part l_regs

8112019 Part L_Regs

httpslidepdfcomreaderfullpart-lregs 131

The Building Regulations 2010

In effect from 1 October 2010

L1B Conservation of fuel and power

in existing dwellings

L1B APPROVEDDOCUMENT

Conservation of fuel and power

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MAIN CHANGES IN THE

2010 EDITION1 This Approved Document L1B came into force

on 1 October 2010 in support of the Buildingand Approved Inspectors (Amendment)Regulations 2010 SI 2010 No 719 The mainchanges to the legal requirements and the

supporting guidance in this edition of Approved Document L1B are as follows

Changes in the legal requirements

2 The exemption from the energy efficiencyprovisions for extensions consisting of aconservatory or porch is amended to grantthe exemption only where any existing wallswindows or doors are retained or replaced ifremoved and where the heating system ofthe building is not extended into theconservatory or porch

3 The list of work in Schedule 4 (work thatneed not be notified to building control) isamended to include the installation ofthermal insulation in a roof space or loftspace where this is the only work carried outand the work is not carried out to complywith any requirement in the BuildingRegulations

Changes in the technical guidance

4 In this Approved Document the guidance isgenerally based upon an elemental approachto demonstrating compliance with additionalguidance that provides greater flexibility Themain technical changes comprise a generalstrengthening of energy efficiency standardsthat are considered reasonable for work onthermal elements controlled fittings andcontrolled services in existing dwellings

5 Amended guidance is given for historic andtraditional buildings which may have anexemption from the energy efficiencyrequirements or where special considerationsapply

6 Amended guidance is given where anextension is a conservatory or porch that isnot exempt from the energy efficiencyrequirements

7 The guidance for the renovation of a thermalelement through the provision of a new layeror through the replacement of an existinglayer has been expanded

8 Guidance is provided for swimming poolbasins (walls and floor) in existing dwellings

Main changes made by the

2010 and 2011 amendmentsThis 2010 edition incorporating the further2010 amendments reflects the changes madeas a result of the Building Regulations 2010Building Approved inspector etc Regulationsand the Building (Amendment) Regulations

2011 The changes mainly reflect regulationnumber changes as a result of re-ordering Therehave been no amendments to the substantiverequirements in Schedule 1(ie Parts A to P) ofthe Building Regulations

Please note the simplification of the definitionof lsquoroom for residential purposesrsquo in regulation2 of the Building Regulations 2010 and theamendment of the definition of ldquorenovationrdquoin regulation 2(1) of the Building (Amendment)Regulations 2011 Please also note that L1(c) hasnow become regulation 40

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Approved Document L1B Conservation of fuel and power

PAGE

Section 1 Introduction 2

What is an Approved Document 2

Consideration of technical risk 2

How to use this Approved Document 2

Where you can get further help 3

Responsibility for compliance 3

Section 2 The requirements 4

LIMITATION ON REQUIREMENTS 6

Section 3 General guidance 7

Key terms 7

Types of work covered by this

Approved Document 8Dwellings within the scope of theenergy efficiency requirements 8

Dwellings exempt from the energyefficiency requirements 8

Notification of work covered by theenergy efficiency requirements 9

Materials and workmanship 10

The Workplace (Health Safety andWelfare) Regulations 1992 11

Section 4 Guidance relating tobuilding work 12

THE EXTENSION OF A DWELLING 12

Reference method 12

Optional approaches with moredesign flexibility 12

Conservatories and porches 12

Swimming pool basins 13

MATERIAL CHANGE OF USE ANDCHANGE OF ENERGY STATUS 13

Material change of use 13

Change of energy status 13

Option providing more design flexibility 14

WORK ON CONTROLLED FITTINGS AND SERVICES 14

Controlled fittings 14

Controlled services 15

COMMISSIONING OF FIXED BUILDINGSERVICES 15

PAGE

Section 5 Guidance on thermal elements 17

THE PROVISION OF THERMAL ELEMENTS 17

U-values 17

Continuity of insulation and airtightness 17

RENOVATION OF THERMAL ELEMENTS 17

RETAINED THERMAL ELEMENTS 18

Section 6 Consequential improvements toenergy performance 19

Section 7 Providing information 20

Appendix A Work to thermal elements 21

Appendix B Documents referred to 24

Appendix C Standards referred to 25

Index 26

Contents L1BN L I N E V E R I N

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L1B

Conservation of fuel and power Approved Document L1B

2

Section 1 Introduction

What is an Approved Document

11 This Approved Document which takeseffect on 1 October 2010 has been approvedand issued by the Secretary of State to providepractical guidance on ways of complying with the

energy efficiency requirements (see Section 2)and regulation 7 of the Building Regulations 2010(SI 20102214) for England and Wales Regulation2(1) of the Building Regulations defines theenergy efficiency requirements as therequirements of regulations 23 26 28 29 40and Part L of Schedule 1 The BuildingRegulations 2010 are referred to throughout theremainder of this Document as lsquothe BuildingRegulationsrsquo

12 The intention of issuing Approved Documentsis to provide guidance about compliance withspecific aspects of building regulations in some

of the more common building situations Theyset out what in ordinary circumstances may beaccepted as reasonable provision for compliancewith the relevant requirement(s) of buildingregulations to which they refer

13 If guidance in an Approved Documentis followed there will be a presumption ofcompliance with the requirement(s) covered bythe guidance However this presumption can beoverturned so simply following guidance doesnot guarantee compliance for example if theparticular case is unusual in some way thenlsquonormalrsquo guidance may not be applicable It is

also important to note that there may well beother ways of achieving compliance with therequirements There is therefore no obligationto adopt any particular solution contained inthis Approved Document if you would preferto meet the relevant requirement in someother way Persons intending to carry outbuilding work should always check with theirbuilding control body either the local authorityor an approved inspector that their proposalscomply with building regulations

14 It is important to note that this ApprovedDocument as well as containing guidance also

contains extracts from the Regulations Suchregulatory text must be complied with as statedFor example the requirement that fixed building services must be commissioned (regulation 44)is a regulatory requirement There is therefore noflexibility to ignore this requirement neither cancompliance with this particular regulation bedemonstrated via any route other than that setout in regulation 44

15 The guidance contained in this ApprovedDocument relates only to the particularrequirements of the Building Regulations that thedocument addresses (set out in Section 2)

However building work may be subject to morethan one requirement of building regulations Insuch cases the work will also have to comply

with any other applicable requirements ofbuilding regulations

16 There are Approved Documents that giveguidance on each of the Parts of Schedule 1 andon regulation 7 A full list of these is provided at

the back of this document

Consideration of technical risk

17 Building work to existing dwellings mustsatisfy all the technical requirements set outin regulations 23 22 28 and 29 of and Schedule1 to the Building Regulations When consideringthe incorporation of energy efficiency measuresin dwellings attention should alsobe paid in particular to the need to comply withPart B (fire safety) Part C (site preparation andresistance to contaminants and moisture) Part E(resistance to the passage of sound) Part F

(ventilation) paragraph G3 (hot water supply andsystems) Part J (combustion appliances and fuelstorage systems) and Part P (electrical safety)of Schedule 1 to the Building Regulations aswell as Part L The adoption of any particularenergy efficiency measure should not involveunacceptable technical risk of for instanceexcessive condensation Designers and buildersshould refer to the relevant Approved Documentsand to other generally available good practiceguidance to help minimise these risks

How to use this Approved Document

18 This Approved Document is subdividedinto seven sections as detailed below Thesesections are followed by supporting appendices

This introductory section sets out the generalcontext in which the guidance in this ApprovedDocument must be considered

Section 2 sets out the relevant legal requirementscontained in the Building Regulations

Section 3 contains general guidance includingthe definition of key terms the types of buildingwork covered by this Approved Documentthe types of building work that are exempt

procedures for notifying work materials andworkmanship and health and safety issues

Section 4 gives guidance on reasonableprovision for various types of building work

Section 5 deals with the particular case of workto thermal elements

Section 6 gives guidance in support of therequirement for consequential improvements for buildings over 1000 m2

Section 7 describes the information that shouldbe provided to occupiers to help them achievereasonable standards of energy efficiency inpractice

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INTRODUCTION L1B

19 In this document the following conventionshave been adopted to assist understanding andinterpretation

a Texts shown against a green background areextracts from the Building Regulations 2010(SI 20102214) or Building (ApprovedInspectors etc) Regulations 2010 (SI 20102215)and set out the legal requirements that relateto compliance with the energy efficiency requirements of building regulations As statedpreviously there is no flexibility in respect ofsuch text it defines a legal requirement notguidance for typical situations It should alsobe remembered that as noted abovebuilding works must comply with all the otherapplicable requirements of building regulations

b Key terms are defined in paragraph 31 andare printed in bold italic text

c Details of technical publications referred toin the text of this Approved Document will be

given in footnotes and repeated as referencesat the end of the document A reference to apublication is likely to be made for one of twomain reasons The publication may containadditional or more comprehensive technicaldetail which it would be impractical toinclude in full in the Approved Document butwhich is needed to fully explain ways ofmeeting the requirements or it is a source ofmore general information The reason for thereference will be indicated in each case Thereference will be to a specified edition of thedocument The Approved Document may beamended from time to time to include newreferences or to refer to revised editionswhere this aids compliance

d Additional commentary in italic text appearsafter some numbered paragraphs Thiscommentary is intended to assist understandingof the immediately preceding paragraph orsub-paragraph or to direct readers tosources of additional information but is notpart of the technical guidance itself

Where you can get further help

110 If you do not understand the technical

guidance or other information set out in this Approved Document and the additional detailedtechnical references to which it directs you thereare a number of routes through which you canseek further assistance

bull the Department for Communities andLocal Government websitewwwcommunitiesgovuk

bull the Planning Portal websitewwwplanningportalgovuk

bull if you are the person undertaking the buildingwork you can seek assistance either from

your local authority building control service orfrom your approved inspector (depending onwhich building control service you are using

bull persons registered with a competent personself-certification scheme may be able to gettechnical advice from their scheme operator

bull if your query is of a highly technical natureyou may wish to seek the advice of aspecialist or industry technical body forthe relevant subject

Responsibility for compliance111 It is important to remember that if youare the person (eg designer builder installer)carrying out building work to which anyrequirement of building regulations applies youhave a responsibility to ensure that the workcomplies with any such requirement The buildingowner may also have a responsibility for ensuringcompliance with building regulation requirementsand could be served with an enforcement noticein cases of non-compliance

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L1B

21 This Approved Document which takeseffect on 1 October 2010 deals with the energyefficiency requirements in the BuildingRegulations Regulation 2(1) of the BuildingRegulations defines the energy efficiency requirements as the requirements of regulations23 26 28 40 and Part L of Schedule 1 Theenergy efficiency requirements relevantto existing dwellings are in regulations 23 28 29and 40 of and Part L of Schedule 1 to thoseRegulations as set out below

Requirements relating to thermal elements ndash Regulation 23

(1) Where a person intends to renovate a thermal element

such work shall be carried out as is necessary to ensure that the

whole thermal element complies with the requirements of

paragraph L1(a)(i) of Schedule 1

(2) Where a thermal element is replaced the new thermal

element shall comply with the requirements of paragraph L1(a)

(i) of Schedule 1

Consequential improvements to energy performance

Regulation 28

(1) Paragraph (2) applies to an existing building with a total

useful floor area over 1000 m2 where the proposed building

work consists of or includesmdash

(a) an extension

(b) the initial provision of any fixed building services or

(c) an increase to the installed capacity of any fixed

building services

(2) Subject to paragraph (3) where this paragraph applies

such work if any shall be carried out as is necessary to ensure

that the building complies with the requirements of Part L of

Schedule 1

(3) Nothing in paragraph (2) requires work to be carried out if

it is not technically functionally or economically feasible

Energy performance certificates ndash Regulation 29

(1) This regulation applies wheremdash

(a) a building is erected or

(b) a building is modified so that it has a greater or fewer

number of parts designed or altered for separate use than it

previously had where the modif ication includes the provision

or extension of any of the fixed services for heating hot water

air conditioning or mechanical ventilation

(2) The person carrying out the work shallmdash

(a) give an energy performance certificate for the building

to the owner of the building and

(b) give to the local authority notice to that effect

including the reference number under which the energy

performance certificate has been registered in accordance withregulation 17F(4)

Section 2 The requirements

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THE REQUIREMENTS L1B

Energy performance certificates ndash Regulation 29 (continued)

(3) The energy performance certificate and notice shall be

given not later than f ive days after the work has been completed

(4) An energy performance certificate mustmdash

(a) express the asset rating of the building in a way

approved by the Secretary of State under regulation 24

(b) include a reference value such as a current legal

standard or benchmark

(c) be issued by an energy assessor who is accredited to

produce energy performance certificates for that category of

building and

(d) include the following informationmdash

(i) the reference number under which the certificate

has been registered in accordance with regulation 30(4)

(ii) the address of the building

(iii) an estimate of the total useful floor area of the

building

(iv) the name of the energy assessor who issued it

(v) the name and address of the energy assessorrsquos

employer or if he is self-employed the name under which he

trades and his address

(vi) the date on which it was issued and

(vii) the name of the approved accreditation scheme of

which the energy assessor is a member

(5) The energy performance certificate must be accompanied

by a recommendation report containing recommendations for

the improvement of the energy performance of the building

issued by the energy assessor who issued the energy

performance certificate

(6) Certification for apartments or units designed or alteredfor separate use in blocks may be basedmdash

(a) except in the case of a dwelling on a common

certification of the whole building for blocks with a common

heating system or

(b) on the assessment of another representative apartment

or unit in the same block

(7) Wheremdash

(a) a block with a common heating system is divided into

parts designed or altered for separate use and

(b) one or more but not all of the parts are dwellings

certification for those parts which are not dwellings may be based on a common certification of all the parts which are not

dwellings

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L1B THE REQUIREMENTS

6


Requirement Limits on application

Schedule 1 ndash Part L Conservation of fuel and power

L1 Reasonable provision shall be made for the conservation of

fuel and power in buildings by

(a) limiting heat gains and lossesmdash

(i) through thermal elements and other parts of the

building fabric and

(ii) from pipes ducts and vessels used for space

heating space cooling and hot water services

(b) providing fixed building services whichmdash

(i) are energy efficient

(ii) have effective controls and

(iii) are commissioned by testing and adjusting as

necessary to ensure they use no more fuel and power than is

reasonable in the circumstances and

Regulation 40 providing to the owner sufficient informationabout the building the fixed building services and their

maintenance requirements so that the building can be operated

in such a manner as to use no more fuel and power than is

reasonable in the circumstances

LIMITATION ON REQUIREMENTS

22 In accordance with regulation 8 of theBuilding Regulations the requirements in Parts Ato D F to K and N (except for paragraphs G2 H2and J7) of Schedule 1 to the Building Regulations

do not require anything to be done except for thepurpose of securing reasonable standards ofhealth and safety for persons in or about buildings(and any others who may be affected by buildingsor matters connected with buildings)

23 Paragraph G2 is excluded as it deals withwater efficiency and paragraphs H2 and J7 areexcluded from regulation 8 because they dealdirectly with prevention of the contamination ofwater Parts E and M (which deal respectivelywith resistance to the passage of sound andaccess to and use of buildings) are excludedfrom regulation 8 because they address the

welfare and convenience of building users Part Lis excluded from regulation 8 because it addressesthe conservation of fuel and power

24 In addition regulation 4(2) of the BuildingRegulations states that where the work is beingcarried out in order to comply with regulation 23(requirements relating to renovation or replacementof a thermal element ) regulation 22 (requirementsrelating to a change of a buildingrsquos energy status)or regulation 28 ( consequential improvements to energy performance) and is not a materialalteration it need comply only with the requirementsof Part L

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L1B

Key terms

31 The following are key terms used in thisdocument

BCB means Building Control Body a local

authority or an approved inspectorCommissioning means the advancement ofa fixed building service following installationreplacement or alteration of the whole or partof the system from the state of static completionto working order by testing and adjusting asnecessary to ensure that the system as a wholeuses no more fuel and power than is reasonable inthe circumstances without prejudice to the needto comply with health and safety requirementsFor each system commissioning includessetting-to-work regulation (that is testing andadjusting repetitively) to achieve the specified

performance the calibration setting up andtesting of the associated automatic controlsystems and recording of the system settingsand the performance test results that have beenaccepted as satisfactory

Consequential improvements means thoseenergy efficiency improvements required byregulation 28

Controlled service or fitting means a service orfitting in relation to which Part G (sanitation hotwater safety and water efficiency) H (drainageand waste disposal) J (combustion appliancesand fuel storage systems) L (conservation of fuel

and power) or P (electrical safety) of Schedule 1to the Building Regulations imposes a requirement

Dwelling means a self-contained unit includinga house or a flat designed to be used separatelyto accommodate a single household ( Rooms for residential purposes are not dwellings so ApprovedDocument L2B applies to work in such buildings)

Energy efficiency requirements means therequirements of regulations 23 26 28 29 and40 of and Part L of Schedule 1 to the BuildingRegulations

In respect of existing dwellings the applicable requirements consist of Part L and regulations 23 38 and 40

Fixed building services means any part of orany controls associated with

a fixed internal or external lighting systems butdoes not include emergency escape lightingor specialist process lighting or

b fixed systems for heating hot water airconditioning or mechanical ventilation

Room for residential purposes means a room ora suite of rooms which is not a dwelling-house or aflat and which is used by one or more persons tolive and sleep and includes a room in a hostel anhotel a boarding house a hall of residence or a

residential home but does not include a room in ahospital or other similar establishment used forpatient accommodation

lsquo Renovationrsquo in relation to a thermal elementmeans the provision of a new layer in the thermalelement (other than where that new layer isprovided solely as a means of repair to a flatroof) or the replacement of an existing layer butexcludes decorative finishes and lsquorenovatersquo shallbe construed accordingly

Simple payback means the amount of time itwill take to recover the initial investment through

energy savings and is calculated by dividingthe marginal additional cost of implementing anenergy efficiency measure by the value of theannual energy savings achieved by that measuretaking no account of VAT When making thiscalculation the following guidance should be used

a the marginal additional cost is the additionalcost (materials and labour) of incorporating(eg) additional insulation not the whole costof the work

b the cost of implementing the measure shouldbe based on prices current at the date theproposals are made known to the BCB andbe confirmed in a report signed by a suitablyqualified person

c the annual energy savings should beestimated using SAP 20091

d for the purposes of this Approved Documentthe energy prices that are current at the timeof the application to building control shouldbe used when evaluating the annual energysavings Current energy prices can be obtainedfrom the DECC website2

Thermal element is defined in regulation 2(3)of the Building Regulations as follows

2(3) In these Regulations lsquothermal elementrsquomeans a wall floor or roof (but does not includewindows doors roof windows or roof-lights)which separates a thermally conditioned part ofthe building (lsquothe conditioned spacersquo) from

a the external environment (including theground) or

b in the case of floors and walls another part ofthe building which is

i unconditioned

1 wwwbrecouksap20092 wwwdeccgovukencontentcmsstatisticspublicationpricespricesaspx

Section 3 General guidance

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L1B GENERAL GUIDANCE

ii an extension falling within class VII inSchedule 2 or

iii where this paragraph applies conditionedto a different temperature

and includes all parts of the element between thesurface bounding the conditioned space and theexternal environment or other part of the building

as the case may be2(4) Paragraph 2(3)(b)(iii) only applies to a buildingwhich is not a dwelling where the other part ofthe building is used for a purpose which is notsimilar or identical to the purpose for which theconditioned space is used

Note that this definition encompasses the walls and floor of a swimming pool basin where this is part of an existing dwelling


Approved Document

32 This Approved Document is intended togive guidance on what in ordinary circumstancesmay be considered reasonable provision forcompliance with the requirements of regulation23 and 28 of and Part L of Schedule 1 to theBuilding Regulations for those carrying outbuilding work to existing dwellings In addition itgives guidance on compliance with regulations43 44 and 27 of the Building Regulations and20(1) (4) and (6) of the Building (ApprovedInspectors etc) Regulations 2010 (SI 20102215)(lsquothe Approved Inspectors Regulationsrsquo)

Buildings exclusively containing rooms for residential purposes such as nursing homes student accommodation and similar are notdwellings and in such cases ApprovedDocument L2B applies

33 In particular this Approved Documentgives guidance on compliance with the energyefficiency requirements where the followingoccurs

a the construction of an extension (seeparagraphs 41 to 49)

b a material change of use or a change to the

buildingrsquos energy status including such workas loft and garage conversions (paragraphs411 to 416)

c the provision or extension of a controlled service or controlled fitting (paragraphs417 to 437)

d the replacement or renovation of a thermalelement (Section 5)

34 Where the activities include building workin a dwelling that is part of a mixed-use buildingaccount should also be taken of the guidance in Approved Document L2B in relation to those

parts of the building that are not dwellingsincluding any common areas

It should be noted that dwellings are defined as self-contained units Rooms for residential

purposes are not dwellings and so ApprovedDocument L2B applies to them

Dwellings within the scope of the

energy efficiency requirements

35 The energy efficiency requirements ofthe Building Regulations apply only to buildings

which are roofed constructions having walls andwhich use energy to condition the indoor climateFor dwellings the requirements will apply to

bull the erection of a dwelling (guidance on this isgiven in Approved Document L1A)

bull the extension of a dwelling other than someextensions falling within Class VII in Schedule2 to the Building Regulations or

bull the carrying out of any building work to or inconnection with an existing dwelling or anextension to an existing dwelling

Dwellings exempt from theenergy efficiency requirements

36 There are two exemptions from the energyefficiency requirements that may apply tobuilding work to existing dwellings or extensionsto existing dwellings

a Buildings which are

bull listed in accordance with section 1 ofthe Planning (Listed Buildings andConservation Areas) Act 1990

bull in a conservation area designated in

accordance with section 69 of that Act orbull included in the schedule of monuments

maintained under section 1 of the AncientMonuments and Archaeological Areas Act 1979

For these buildings the exemption appliesonly to the extent that compliance with theenergy efficiency requirements wouldunacceptably alter the character orappearance of such existing dwellingsGuidance on these buildings is given inparagraphs 37 to 314 below

b Carports covered yards covered ways andsome conservatories or porches attached toexisting dwellings Guidance on these isgiven at paragraphs 315 and 316 below

Historic and traditional buildings which mayhave an exemption

37 As mentioned above in paragraph 36a thefollowing classes of buildings have an exemptionfrom the energy efficiency requirements wherecompliance would unacceptably alter thecharacter or appearance of the buildings

a listed buildings

b buildings in conservation areas and

c scheduled ancient monuments

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GENERAL GUIDANCE L1B

9


Historic and traditional buildings wherespecial considerations may apply

38 There are three further classes of buildingswhere special considerations in making reasonableprovision for the conservation of fuel or powermay apply

a buildings which are of architectural and

historical interest and which are referred to asa material consideration in a local authorityrsquosdevelopment plan or local developmentframework

b buildings which are of architectural andhistorical interest within national parks areasof outstanding natural beauty registeredhistoric parks and gardens registeredbattlefields the curtilages of scheduledancient monuments and world heritage sites

c buildings of traditional construction withpermeable fabric that both absorbs andreadily allows the evaporation of moisture

39 When undertaking work on or inconnection with a building that falls within oneof the classes listed above the aim should be toimprove energy efficiency as far as is reasonablypracticable The work should not prejudice thecharacter of the host building or increase the riskof long-term deterioration of the building fabricor fittings

310 The guidance given by English Heritage3 should be taken into account in determiningappropriate energy performance standards forbuilding work in historic buildings

311 In general new extensions to historic ortraditional dwellings should comply with thestandards of energy efficiency as set out in this Approved Document The only exception wouldbe where there is a particular need to matchthe external appearance or character of theextension to that of the host building (seeparagraph 42)

312 Particular issues relating to work in historicbuildings that warrant sympathetic treatment andwhere advice from others could therefore bebeneficial include

a restoring the historic character of a buildingthat has been subject to previousinappropriate alteration eg replacementwindows doors and rooflights

b rebuilding a former historic building (egfollowing a fire or filling a gap site in a terrace)

c making provisions enabling the fabric of historicbuildings to lsquobreathersquo to control moisture andpotential long-term decay problems

313 In assessing reasonable provision forenergy efficiency improvements for historicbuildings of the sort described in paragraphs 37

and 38 it is important that the BCB takes intoaccount the advice of the local authorityrsquos

3 wwwenglish-heritageorguk

conservation officer The views of the conservationofficer are particularly important where buildingwork requires planning permission andor listedbuilding consent

314 Other classes of buildings to which specialconsiderations apply are usually non-domestic incharacter and so are covered in ADL2A and ADL2B

Conservatories and porches

315 Regulation 21 of the Building Regulationsexempts some conservatory and porch extensionsfrom the energy efficiency requirements Theexemption applies only for conservatories or porches

bull which are at ground level

bull where the floor area is less than 30 m2

bull where the existing walls doors and windowsin the part of the dwelling which separatesthe conservatory are retained or if removedreplaced by walls windows and doors whichmeet the energy efficiency requirements and

bull where the heating system of the dwelling isnot extended into the conservatory or porch

316 Where any conservatory or porch doesnot meet all the requirements in the precedingparagraph it is not exempt and must complywith the relevant energy efficiency requirements(see paragraphs 48 and 49 below)

Notification of work covered by

the Energy Efficiency requirements

317 In most instances in order to comply withthe Building Regulations it will be necessary tonotify a BCB before the work starts Where youchoose to use the local authority and any workrelates to the common parts of a block of flatsthis must be by deposit of full plans For otherexisting dwellings this could be either in the formof a deposit of full plans or by a building noticeThere is no set procedure where the BCB is an Approved Inspector provided they have beennotified at least 5 days before work starting

318 In certain situations however you do notneed to notify a BCB

a Where the work is being carried out by aperson registered with a relevant competentperson self-certification scheme listed inSchedule 3 to the Building Regulations noadvance notification to the BCB is needed(see paragraphs 319 to 322)

b Where the work involves an emergency repaireg to a failed boiler or a leaking hot watercylinder in accordance with regulation 12(7)of the Building Regulations there is no needto delay making the repair in order to makean advance notification to the BCB Howeverin such cases it will still be necessary for thework to comply with the relevant requirementsand to give a notice to the BCB at the earliestopportunity unless an installer registered under

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10


an appropriate competent person schemecarries out the work A completion certificatecan then be issued in the normal way

c Where the work is of a minor nature asdescribed in the schedule of non-notifiablework (Schedule 4 to the Building Regulations)the work must still comply with the relevantrequirements but need not be notified to the BCB (see paragraphs 323 to 325)

Competent person self-certification schemes

319 It is not necessary to notify a BCB inadvance of work which is to be carried out bya person registered with a competent personself-certification scheme listed in Schedule 3 tothe Building Regulations In order to join such ascheme a person must demonstrate competenceto carry out the type of work the scheme coversand also the ability to comply with all relevantrequirements in the Building Regulations

320 Where work is carried out by a personregistered with a competent person schemeregulation 20 of the Building Regulations 2010and regulation 20(1) of the Building (ApprovedInspectors etc) Regulations 2010 require that theoccupier of the building be given within 30 days ofthe completion of the work a certificate confirmingthat the work complies fully with all applicablebuilding regulation requirements There is also arequirement to give the BCB a notice of the workcarried out again within 30 days of the completionof the work These certificates and notices areusually made available through the scheme operator

321 BCBs are authorised to accept thesecertificates and notices as evidence of compliancewith the requirements of the Building RegulationsLocal authority inspection and enforcementpowers remain unaffected although they arenormally used only in response to a complaintthat work does not comply

322 A list of authorised self-certification schemesand the types of work for which they are authorisedcan be found at wwwcommunitiesgovuk

Work which need not be notified

323 Schedule 4 to the Building Regulations

sets out types of work where there is no requirementto notify a BCB that work is to be carried outThese types of work are mainly of a minor naturewhere there is no significant risk to health safetyor energy efficiency Note that the health safetyand energy efficiency requirements continue toapply to these types of work and that only theneed to notify a BCB has been removed In additionwhere only non-notifiable work is carried out by amember of a competent person self-certificationscheme there is no requirement for a certificateof building regulations compliance to be given tothe occupier or the BCB

324 The types of non-notifiable work inSchedule 4 relevant to the energy efficiency requirements of the Regulations are

a In a heating hot water ventilation or air-

conditioning system the replacement of anypart which is not a combustion appliance(such as a radiator valve or pump) or theaddition of an output device (such as aradiator or fan) or the addition of a controldevice (such as a thermostatic radiator valve)However the work will remain notifiablewhenever commissioning is possible and

necessary to enable a reasonable use of fueland power (see paragraphs 430 to 437)

b The installation of a stand-alone self-contained fixed heating hot water ventilationor air-conditioning service Such servicesmust consist only of a single appliance andany associated controls and must not beconnected to or form part of any other fixed building service Examples of non-notifiableservices would be a fixed electric heater amechanical extractor fan in a kitchen orbathroom and a room air-conditioning unitHowever if any of the following apply the

work will remain notifiable building worki the service is a combustion appliance

ii any electrical work associated with theinstallation is notifiable

iii commissioning is possible and wouldaffect the servicersquos energy efficiency (seeparagraphs 430 to 438)

iv in the case of a ventilation appliance theappliance is installed in a room containinga natural draught open-flued combustionappliance or service such as a gas firewhich uses a chimney as its flue

c Installation of thermal insulation in a roofspace or loft space where this is the onlywork carried out and the work is not carriedout to comply with any requirement in theBuilding Regulations ie the work is carriedout voluntarily

325 Schedule 4 also sets out what typesof electrical installation work in dwellings arenon-notifiable Full information on this is givenin Approved Document P

Materials and workmanship

326 Any building work which is subject to therequirements imposed by Schedule 1 to theBuilding Regulations should in accordance withregulation 7 be carried out with proper materialsand in a workmanlike manner

327 You may show that you have compliedwith regulation 7 in a number of ways Theseinclude demonstrating the appropriate use of

bull a product bearing CE marking in accordancewith the Construction Products Directive(89106EC)4 as amended by the CE MarkingDirective (9368EC)5 the Low Voltage

4 As implemented by the Construction Products Regulations 1991

(SI 19911620)5 As implemented by the Construction Products (Amendment) Regulations

1994 (SI 19943051)

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11


Directive (200695EC)6 and the EMCDirective (2004108 EC)7

bull a product complying with an appropriatetechnical specification (as defined in thoseDirectives mentioned above) a BritishStandard or an alternative national technicalspecification of a Member State of theEuropean Union or Turkey 8 or of anotherState signatory to the Agreement on theEuropean Economic Area (EEA) that providesan equivalent level of safety and protection

bull a product covered by a national or Europeancertificate issued by a European Technical Approval Issuing body provided theconditions of use are in accordance with theterms of the certificate

328 You will find further guidance in the Approved Document which specifically supportsregulation 7 on materials and workmanship

Independent certification schemes329 There are many UK product certificationschemes Such schemes certify compliance withthe requirements of a recognised standard that isappropriate to the purpose for which the materialis to be used Materials which are not so certifiedmay still conform to a relevant standard

330 Many certification bodies that approveproducts under such schemes are accreditedby the United Kingdom Accreditation Service(UKAS) Such bodies can issue certificates onlyfor the categories of product covered under theterms of their accreditation

331 BCBs may take into account thecertification of products components materialsor structures under such schemes as evidence ofcompliance with the relevant standard Similarly BCBs may accept the certification of the installationor maintenance of products componentsmaterials or structures under such schemes asevidence of compliance with the relevant standardNonetheless before accepting that certificationconstitutes compliance with building regulationsa BCB should establish in advance that therelevant scheme is adequate for that purpose

Standards and technical specifications332 Building regulations are made for specificpurposes including securing the health safetywelfare and convenience of people in or aboutbuildings furthering the conservation of fuel andpower furthering the protection or enhancementof the environment and facilitating sustainabledevelopment Guidance contained in standardsand technical approvals referred to in ApprovedDocuments may be relevant to compliance withbuilding regulations to the extent that it relates tothose purposes However it should be noted that

6 As implemented by the Electrical Equipment (Safety) Regulations 1994

(SI 19943260)7 As implemented by the Electromagnetic Compatibility Regulations 2006

(SI 20063418)8 Decision No 195 of the ECndashTurkey Association Council of 22 December 1995

guidance in standards and technical approvalsmay also address other aspects of performancesuch as serviceability or aspects which althoughthey relate to health and safety are not coveredby building regulations

333 When an Approved Document makesreference to a named standard or document therelevant version of the standard or document isthe one listed at the end of the ApprovedDocument Until the reference in the ApprovedDocument is revised the standard or documentlisted remains the approved source but if theissuing body has published a revised or updatedversion any content that addresses the relevantrequirements of the Building Regulations may beused as a source of guidance

334 The appropriate use of a product thatcomplies with a European Technical Approval asdefined in the Construction Products Directivewill meet the relevant requirements

335 The Department for Communities andLocal Government intends to issue periodicamendments to its Approved Documents toreflect emerging harmonised Europeanstandards Where a national standard is to bereplaced by a European harmonised standardthere will be a coexistence period during whicheither standard may be referred to At the endof the coexistence period the national standardwill be withdrawn

The Workplace (Health Safety and

Welfare) Regulations 1992

336 The Workplace (Health Safety andWelfare) Regulations 1992 as amended apply tothe common parts of flats and similar buildings ifpeople such as cleaners wardens and caretakersare employed to work in these common partsThese Regulations contain some requirementswhich affect building design The main requirementsare now covered by the Building Regulationsbut for further information see Workplace health safety and welfare Workplace (Health Safety andWelfare) Regulations 1992 Approved Code ofPractice and guidance HSE publication L24 1996

337 Where the requirements of the BuildingRegulations that are covered by this ApprovedDocument do not apply to dwellings theprovisions may still be required in the situationsdescribed above in order to satisfy the WorkplaceRegulations

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L1B

THE EXTENSION OF A DWELLING

Reference method

Fabric standards

41 Reasonable provision would be for theproposed extension to incorporate the following

a newly constructed thermal elements thatmeet the standards set out in paragraphs 51to 56

b doors windows roof windows and rooflightsthat meet the standards set out in paragraphs419 to 423

c improvements to fabric elements that are tobecome thermal elements following theguidance in paragraphs 56 to 511

Area of windows roof windows and doors42 In most circumstances reasonableprovision would be to limit the total area ofwindows roof windows and doors in extensionsso that it does not exceed the sum of

a 25 per cent of the floor area of the extensionplus

b the total area of any windows or doors whichas a result of the extension works no longerexist or are no longer exposed

As a general guide if the area of glazing is much less than 20 per cent of the total floor area some

parts of the extension and especially the part ofthe dwelling it covers may experience poor levelsof daylight resulting in increased use of electric lighting Areas of glazing greater than 25 per cent may be acceptable especially if this is required to make the extension consistent with the external appearance or character of the host buildingIn such cases and where practical either theU-value of the window should be improved relative to the standard set out in paragraph 41b or other compensating measures appliedfollowing the guidance set out in paragraphs 44 to 47

Heating and lighting in the extension

43 Where a fixed building service isprovided or extended as part of constructing theextension reasonable provision would be tofollow the guidance in paragraphs 426 to 437

Optional approaches with more

design flexibility

44 The approach set out in paragraphs 41to 43 is somewhat prescriptive The followingparagraphs offer more flexible approaches to

demonstrating that reasonable provision hasbeen made These alternative approaches allowsome elements of the design to be relaxedthrough compensating measures elsewhere

Area-weighted U-value method

45 One way of complying would be toshow that the area-weighted U-value of all theelements in the extension is no greater than thatof an extension of the same size and shape that

complies with the fabric standards referred to inparagraph 41 and the opening area standardsin paragraph 42 Any fixed building service provided or extended as part of constructingthe extension should follow the guidance inparagraphs 424 to 437

The area-weighted U-value is given by thefollowing expression

(U1 A 1 ) (U2 x A 2 ) (U3 x A 3 ) hellip)983092 (A 1 A 2 A 3 hellip)

Whole dwelling calculation method

46 Where even greater design flexibility isrequired reasonable provision would be to useSAP 2009 to show that the calculated carbondioxide (CO

2 ) emission rate from the dwelling

with its proposed extension is no greater than forthe dwelling plus a notional extension built to thestandards of paragraphs 41 to 43 The openingsin the notional extension should conform withparagraph 42 with door area set equal to thedoor area of the proposed extension with theremainder of the openings being classified aswindows The data in SAP 2009 Appendix Scan be used to estimate the performance of theelements of the existing building where these

are unknown

Approved Document C gives limiting values for individual elements to minimise condensation risk

47 If as part of achieving the standard set outin paragraph 46 upgrades are proposed to theexisting dwelling such upgrades should beimplemented to a standard that is no worse thanset out in the relevant guidance contained in this Approved Document The relevant standards forimproving retained thermal elements are as setout in column (b) of Table 3

Where it is proposed to upgrade the original

building the standards set out in this ApprovedDocument are cost-effective and should be implemented in full It will be worthwhile implementing them even if the improvement is greater than necessary to achieve complianceIn some cases therefore the standard of theextended dwelling may be better than that required by paragraph 46 alone Paragraph 47 sets limits on design flexibility and ensures that no cost-effective improvement opportunities aretraded away


48 Where the extension is a conservatoryor porch that is not exempt from the energyefficiency requirements (see paragraphs 315

Section 4 Guidance relating to building work

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GUIDANCE RELATING TO BUILDING WORK L1B

and 316 above) then reasonable provisionwould be to provide

a Effective thermal separation between theheated area in the existing dwelling iethe walls doors and windows betweenthe dwelling and the extension should beinsulated and draught proofed to at leastthe same extent as in the existing dwelling

b Independent temperature and onoff controlsto any heating system installed within theextension Any fixed building service installedwithin the extension should also conform to thestandards set out in paragraphs 424 to 437

c Glazed elements should meet the standardsset out in Table 1 and opaque elementsshould meet the standards set out in Table 2However the limitations on total area ofwindows roof windows and doors as setout at paragraph 42 above do not apply

49 Removing and not replacing any or all ofthe thermal separation between the dwelling andan existing exempt extension or extending thedwellingrsquos heating system into the extensionmeans the extension ceases to be exempt (seeparagraphs 315 and 316 above) This constitutesa change to the buildingrsquos energy status(Regulation 22) In such situations the extensionshould be treated as a conventional extensionand reasonable provision would be to demonstratethat the extension meets the guidance set out inparagraphs 41 to 47 above

Swimming pool basins

410 Where a swimming pool is being providedin a building the U-value of the basin (walls andfloor) should be not worse than 025 Wm2K ascalculated according to BS EN ISO 133709

MATERIAL CHANGE OF USE AND

CHANGE OF ENERGY STATUS

Material change of use

411 Material changes of use (see regulation 5of the Building Regulations) covered by thisdocument are where after the change

a the building is used as a dwelling wherepreviously it was not

b the building contains a flat where previouslyit did not or

c the building which contains at least onedwelling contains a greater or lesser numberof dwellings than it did previously

9 BS EN ISO 13370 Thermal performance of buildings Heat transfer via

the ground Calculation methods

Change of energy status

412 A change to a buildingrsquos energy status isdefined in regulation 2(1) as

any change which results in a building becominga building to which the energy efficiencyrequirements of these Regulations apply wherepreviously it was not

413 The requirements relating to a changeto energy status are in regulation 22

Where there is a change in a buildingrsquos energystatus such work if any shall be carried outto ensure that the building complies with theapplicable requirements of regulation 40 andPart L of Schedule 1

414 In this regulation lsquobuildingrsquo means thebuilding as a whole or parts of the building thathave been designed or altered to be usedseparately

For example this could occur where a previouslyunheated building or parts of the building that have been designed or altered to be used separately were to be heated in future or where a previously exempt building were no longerwithin the exempted categories A material alteration (regulation 3(2) and (3)) may result in a change in buildings energy status

415 In normal circumstances reasonableprovision where there is a material change ofuse or a change to the buildingrsquos energy statuswould be

a Where controlled services or fittings arebeing provided or extended to meet thestandards set out in paragraphs 417 to 437If the area of openings in the newly createddwelling is more than 25 per cent of the totalfloor area either the area of openings shouldbe reduced to be not greater than 25 per centor the larger area should be compensated forin some other way using the proceduredescribed in paragraph 416

b Where the work involves the provision of athermal element to meet the standards setout in paragraphs 51 to 56

For the purposes of Building Regulations provision means both new and replacement elements

c Where any thermal element is beingretained to upgrade it following the guidancegiven in paragraphs 511 to 513

d Where an existing window (including roofwindow or rooflight) or door which separatesa conditioned space from an unconditionedspace or the external environment has aU-value that is worse than 33 Wm2K toprovide replacement units following theguidance in paragraphs 419 to 423

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L1B GUIDANCE RELATING TO BUILDING WORK

14


Option providing more design

flexibility

416 To provide more design flexibility SAP2009 can be used to demonstrate that the totalCO

2 emissions from all the dwellings in the

building as it will become are no greater than ifeach dwelling had been improved following the

guidance set out in paragraph 415

WORK ON CONTROLLED

FITTINGS AND SERVICES

417 Controlled services or fittings aredefined in regulation 2 as follows

Controlled service or fitting means a service orfitting in relation to which Part G H J L or P ofSchedule 1 imposes a requirement

418 In the context of this Approved Documentthe application of the term controlled fitting to awindow roof window rooflight or door refers to awhole unit ie including the frame Consequentlyreplacing the glazing whilst retaining an existingframe is not providing a controlled fitting andso such work is not notifiable and does not haveto meet the Part L standards although wherepractical it would be sensible to do so Similararguments apply to a new door in an existing frame

Controlled fittings

419 Where windows roof windows rooflightsor doors are to be provided reasonable provision

in normal cases would be the installation ofdraught-proofed units whose performance is noworse than given in Table 1 In addition insulatedcavity closers should be installed where appropriateWhere the replacement windows are unable tomeet the requirements of Table 1 because of theneed to maintain the external appearance of thefaccedilade or the character of the building replacementwindows should meet a centre pane U-valueof 12Wm2K or single glazing should besupplemented with low-e secondary glazing Inthis latter case the weather stripping should be onthe secondary glazing to minimise condensationrisk between the primary and secondary glazing

420 U-values shall be calculated using themethods and conventions set out in BR 44310and should be based on the whole unit (ie in thecase of a window the combined performance ofthe glazing and frame) The U-value of thewindow can be calculated for

a the smaller of the two standard windowsdefined in BS EN 14351-111 or

b the standard window configuration set outin BR 443 or

c the specific size and configuration of theactual window

10 BR 443 Conventions for U-value calculations BRE 200611 EN 14351-1 Windows and doors ndash Product standard performance

characteristics 2006

SAP 2009 Table 6e gives values for differentwindow configurations that can be used in the absence of test data or calculated values

421 The U-values for roof windows androoflights given in this Approved Document arebased on the U-value having been assessedwith the roof window or rooflight in the verticalposition If a particular unit has been assessedin a plane other than the vertical the standardsgiven in this Approved Document should bemodified by making an adjustment that isdependent on the slope of the unit followingthe guidance in BR 443

Table 1 Standards for controlledfittings

Fitting Standard

Window roof window orrooflight

WER Band C or better (seeparagraph 422) or U-value

16 Wm2

KDoors with gt50 of internalface glazed

U-value = 18 Wm2K

Other doors U-value = 18 Wm2K

422 The Window Energy Rating (WER) is givenby the following equation

WER 1967 ((1 f) gglass ) ndash 685 (U (00165 AL))

Where f is the frame factor ie the percentage ofthe window obscured by frame and gaskets

gglass is the normal total solar energy transmittanceof the glass as determined by BS EN 410

U is the whole window U-value as specified inparagraph 420 and 421 and

AL is the air leakage through the window inm3 hm2 at 50 Pa pressure difference based ontesting to BS 6375ndash12009 Note that AL isbased on the whole window area not per unitlength of opening light

The following rating bands define the windowenergy rating label

Band A WER

0Band B 0 WER ndash10

Band C ndash10 WER ndash20

Band D ndash20 WER ndash30

Band E ndash30 WER ndash50

Band F ndash50 WER ndash70

Band G ndash70 WER

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15


BCBs may accept a WER declaration from acertification scheme that provides a quality-assuredprocess and supporting audit trail from calculatingthe performance of the window through to installationas evidence of compliance Notwithstanding thesuggested performance values set out aboveguidance on energy-efficient windows isavailable from the Energy Saving Trust12

423 If a window is enlarged or a new onecreated then the area of windows roof windowsrooflights and doors should not exceed 25 percent of the total floor area of the dwelling unlesscompensating measures are included elsewherein the work

Controlled services

424 Whenever a fixed building service isextended or provided reasonable provisionwould be demonstrated by following theguidance set out in the Domestic BuildingServices Compliance Guide13 The Guide coversthe following services

a heating and hot water systems (includinginsulation of pipes ducts and vessels

b mechanical ventilation

c mechanical coolingair-conditioning

d fixed internal lighting

e fixed external lighting

f renewable energy systems

425 The efficiency claimed for the fixed building service should be based on the appropriate teststandard as set out in the Domestic BuildingServices Compliance Guide and the test datashould be certified by a notified body It would bereasonable for BCBs to accept such data at facevalue In the absence of such quality-assureddata BCBs should satisfy themselves that theclaimed performance is justified

426 When replacing an existing appliancethe efficiency of the new appliance should notbe significantly less than the efficiency of theappliance being replaced If the replacementinvolves a fuel switch then the relative carbonemissions associated with the new and existingfuels should be considered when assessing thereasonableness of the proposed new applianceThe Domestic Building Services Compliance Guidecontains the detailed guidance on this issue

427 If a renewable energy generator suchas a wind turbine or photovoltaic array is beingreplaced the new system should have anelectrical output that is not less than theoriginal installation

12 httpwwwenergysavingtrustorgukHome-improvements-and-

productsHome-insulation-glazingGlazing13 Domestic Building Services Compliance Guide DCLG 2010 edition

428 When replacing a heating applianceconsideration should be given to connectingto any existing local heat networks If the workinvolves pipework changes consideration shouldbe given to providing capped off connections tofacilitate subsequent connection to a plannedlocal heat network

429 If a particular technology is not coveredin the Domestic Building Services ComplianceGuide reasonable provision would be demonstratedby showing that the proposed technology givesa performance that is no worse than a referencesystem of the same type whose details are givenin the Guide

COMMISSIONING OF FIXED

BUILDING SERVICES

430 Paragraph L1(b)(iii) of Schedule 1 to theBuilding Regulations requires fixed building services to be commissioned by testing andadjustment as necessary to ensure that they useno more fuel and power than is reasonable in thecircumstances In order to demonstrate that theheating and hot water systems have beenadequately commissioned regulation 44 states

44 Commissioning

(1) This regulation applies to building work inrelation to which paragraph F1(2) of Schedule 1imposes a requirement but does not apply tothe provision or extension of any fixed system formechanical ventilation or any associated controlswhere testing and adjustment is not possible

(2) This regulation applies to building work inrelation to which paragraph L1(b) of Schedule 1imposes a requirement but does not apply tothe provision or extension of any fixed buildingservice where testing and adjustment is notpossible or would not affect the energy efficiencyof that fixed building service

(3) Where this regulation applies the personcarrying out the work shall for the purpose ofensuring compliance with paragraph F1(2) orL1(b) of Schedule 1 give to the local authority anotice confirming that the fixed building services

have been commissioned in accordance with aprocedure approved by the Secretary of State

(4) The notice shall be given to the local authorityndash

a not later than the date on which the noticerequired by regulation 16(4) is required to begiven or

b where that regulation does not apply not morethan 30 days after completion of the work

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431 Reasonable provision would be to preparea commissioning plan identifying the systemsthat need to be tested and the tests that will becarried out The notice required by regulation20C should confirm that the commissioning planhas been followed and that every system hasbeen inspected in an appropriate sequence andto a reasonable standard and that the test results

confirm that performance is reasonably inaccordance with the design requirements

432 Not all fixed building services will need tobe commissioned With some systems adjustmentis not possible as the only controls are lsquoonrsquo andlsquooffrsquo switches Examples of this would be somemechanical extraction systems or single fixedelectrical heaters In other cases commissioning would be possible but in the specific circumstanceswould have no effect on energy use

Fixed building services which do not requirecommissioning should be identified in thecommissioning plan along with the reasonfor not requiring commissioning

433 Where commissioning is carried out itmust be done in accordance with a procedureapproved by the Secretary of State For heatingand hot water systems the approved proceduresare set out in the Domestic Building ServicesCompliance Guide For ventilation systemsan approved procedure would be to followthe guidance in the Domestic VentilationCompliance Guide14

434 Commissioning is often carried out by theperson who installs the system In other cases it

may be carried out by a subcontractor or by aspecialist firm It is important that whoever carriesit out follows the relevant approved procedure indoing so

435 Where a building notice or full plans havebeen given to a local authority BCB the notice ofcompletion of commissioning should be given tothat BCB within 5 days of the completion of thecommissioning work In other cases for examplewhere work is carried out by a person registeredwith a competent person scheme (see paragraphs319 to 322) it must be given within 30 days

14 Domestic Ventilation Compliance Guide DCLG 2010

436 Where an approved inspector is the BCBthe notice of completion of commissioning should generally be given to the approvedinspector within 5 days of the completion ofwork However where the work is carried outby a person registered with a competent personscheme (see paragraph 319 to 322) the noticemust be given within 30 days Where the

installation of fixed building services whichrequire commissioning is carried out by aperson registered with a competent personscheme the notice of commissioning will begiven by that person

437 Until the BCB receives the commissioningnotice it cannot be reasonably satisfied that Part Lhas been complied with and consequently isunlikely to be able to give a completionfinalcertificate

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L1B

51 New thermal elements must comply withPart L1(a)(i) of Schedule 1 to the BuildingRegulations Work on existing thermal elements must comply with regulation 23 of the BuildingRegulations which states

23ndash(1) Where a person intends to renovate athermal element such work shall be carried outas is necessary to ensure that the whole thermalelement complies with the requirements ofparagraph L1(a)(i) of Schedule 1

(2) Where a thermal element is replaced the newthermal element shall comply with the requirementsof paragraph L1(a)(i) of Schedule 1

THE PROVISION OF THERMAL

ELEMENTS

U-values52 U-values shall be calculated using themethods and conventions set out in BR 443

53 Reasonable provision for newly constructedthermal elements such as those constructedas part of an extension would be to meet thestandards set out in Table 2

54 Reasonable provision for those thermalelements constructed as replacements forexisting elements would be to meet the standardsset out in Table 2

Table 2 Standards for new thermalelements

Element1 Standard (Wm2K)2

Wall 028

Pitched roof ndash insulation at ceiling level 016

Pitched roof ndash insulation at rafter level 018

Flat roof or roof with integral insulation 018

Floors3 0224

Swimming pool basin 025

Notes

1 lsquoRoofrsquo includes the roof parts of dormer windows and lsquowallrsquoincludes the wall parts (cheeks) of dormer windows

2 Area-weighted average values

3 A lesser provision may be appropriate where meeting such astandard would result in a reduction of more than 5 in theinternal floor area of the room bounded by the wall

4 A lesser provision may be appropriate where meeting such a standardwould create significant problems in relation to adjoining floor levelsThe U-value of the floor of an extension can be calculated using theexposed perimeter and floor area of the whole enlarged dwelling

Continuity of insulation and

airtightness

55 The building fabric should be constructedso that there are no reasonably avoidable thermal

bridges in the insulation layers caused by gapswithin the various elements at the joints betweenelements and at the edges of elements suchas those around window and door openingsReasonable provision should also be made toreduce unwanted air leakage through the newenvelope parts The work should comply with allthe requirements of Schedule 1 but particularattention should be paid to Parts F and J

56 A suitable approach to showing therequirement has been achieved would be toadopt Accredited Construction Details atwwwplanningportalgovuk

It is impractical to expect thermal bridge andtemperature factor calculations for work inexisting buildings

RENOVATION OF THERMAL

ELEMENTS

57 For the purposes of this Approved Document renovation of a thermal element through

a the provision of a new layer means either ofthe following activities

i Cladding or rendering the external surface

of the thermal element or

ii Dry-lining the internal surface of athermal element

b the replacement of an existing layer meanseither of the following activities

i Stripping down the element to expose thebasic structural components (brick blockwork timbermetal frame joistsrafters etc) and then rebuilding toachieve all the necessary performancerequirements As discussed in paragraph39 particular considerations apply to

renovating elements of traditionalconstruction or

ii Replacing the water proof membrane ona flat roof

58 Where a thermal element is subject to a renovation through undertaking an activity listedin paragraph 57a or 57b the performance of thewhole element should be improved to achieveor better the relevant U-value set out in column(b) of Table 3 provided the area to be renovatedis greater than 50 per cent of the surface of theindividual element or 25 per cent of the total

building envelope When assessing this areaproportion the area of the element should betaken as that of the individual element not all theelements of that type in the building The area of

Section 5 Guidance on thermal elements

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L1B GUIDANCE ON THERMAL ELEMENTS

the element should also be interpreted in thecontext of whether the element is beingrenovated from inside or outside eg if removingall the plaster finish from the inside of a solidbrick wall the area of the element is the area ofexternal wall in the room If removing externalrender it is the area of the elevation in which thatwall sits

This means that if all the roofing on the flat roof of an extension is being stripped down the area ofthe element is the roof area of the extension notthe total roof area of the dwelling Similarly if the rear wall of a single-storey extension was being re-rendered it should be upgraded to the standardsof Table 3 column (b) even if it was less than50 per cent of the total area of the buildingelevation when viewed from the rear If plaster is being removed from a bedroom wall the relevant area is the area of the external wall in the room not the area of the external elevation whichcontains that wall section This is because the

marginal cost of dry-lining with insulated plasterboard rather than plain plasterboard is small

59 If achievement of the relevant U-value setout in column (b) of Table 3 is not technically orfunctionally feasible or would not achieve a simple payback of 15 years or less the elementshould be upgraded to the best standard that istechnically and functionally feasible and whichcan be achieved within a simple payback of nogreater than 15 years Guidance on this approachis given in Appendix A

510 When renovating thermal elements thework should comply with all the requirements inSchedule 1 but particular attention should bepaid to Parts F and J

RETAINED THERMAL ELEMENTS

511 Part L of Schedule 1 to the BuildingRegulations applies to retained thermalelements in the following circumstances

a where an existing thermal element is part ofa building subject to a material change of use

b where an existing element is to become part ofthe thermal envelope where previously it wasnot eg as part of a loft or garage conversionwhere the space is now to be heated

512 Reasonable provision would be to upgradethose thermal elements whose U-value is worsethan the threshold value in column (a) of Table 3to achieve the U-values given in column (b) ofTable 3 provided this is technically functionallyand economically feasible A reasonable test ofeconomic feasibility is to achieve a simple payback of 15 years or less Where the standardgiven in column (b) is not technically functionally

or economically feasible then the thermalelement should be upgraded to the beststandard that is technically and functionallyfeasible and delivers a simple payback period of15 years or less Generally this lesser standardshould not be worse than 07 Wm2K

Examples of where lesser provision than column(b) might apply are where the thickness of the additional insulation might reduce usable floor area of any room by more than 5 per cent orcreate difficulties with adjoining floor levels orwhere the weight of the additional insulation might not be supported by the existing structural

frame513 When upgrading retained thermalelements the work should comply with allthe requirements in Schedule 1 but particularattention should be paid to Parts F and J

Table 3 Upgrading retained thermal elements

Element1 (a) Threshold U-value Wm2middotK 8 (b) Improved U-value Wm2middotK 8

Wall ndash cavity insulation2 070 055

Wall ndash external or internal insulation3 070 030

Floor45 070 025

Pitched roof ndash insulation at ceiling level 035 016

Pitched roof ndash insulation between rafters6 035 018

Flat roof or roof with integral insulation7 035 018

1 lsquoRoofrsquo includes the roof parts of dormer windows and lsquowallrsquo includes the wall parts (cheeks) of dormer windows

2 This applies only in the case of a wall suitable for the installation of cavity insulation Where this is not the case it should be treated as lsquowall ndash external orinternal insulationrsquo

3 A lesser provision may be appropriate where meeting such a standard would result in a reduction of more than 5 in the internal floor area of the roombounded by the wall

4 The U-value of the floor of an extension can be calculated using the exposed perimeter and floor area of the whole enlarged building

5 A lesser provision may be appropriate where meeting such a standard would create significant problems in relation to adjoining floor levels

6 A lesser provision may be appropriate where meeting such a standard would create limitations on head room In such cases the depth of the insulationplus any required air gap should be at least to the depth of the rafters and the thermal performance of the chosen insulant should be such as to achievethe best practicable U-value

7 A lesser provision may be appropriate if there are particular problems associated with the load-bearing capacity of the frame or the upstand height


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L1B

61 Regulation 28 of the Building Regulationsmay require additional work to be undertaken tomake an existing building more energy efficient

when certain types of building work are proposed62 This requirement arises in existing buildingswith a total useful floor area of over 1000 m2 where the proposed work consists of

a an extension

b the initial provision of any fixed building service (other than a renewable energygenerator)

c an increase to the installed capacity of anyfixed building service (other than arenewable energy generator)

63 Consequential improvements shouldonly be carried out to the extent that they aretechnically functionally and economically feasible

64 Only a relatively small number of existingdwellings will exceed 1000 m2 in size Where thereis doubt the BCB can be consulted for advice

65 Technical guidance on achieving compliancewith regulation 28 is not given in this ApprovedDocument but where the regulation applies it isavailable in Approved Document L2B

Section 6 Consequential improvements toenergy performance

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L1B

71 On completion of the work in accordancewith regulation 40 the owner of the dwelling should be provided with sufficient informationabout the building the fixed building services and their operating and maintenancerequirements so that the dwelling can be operatedin such a manner as to use no more fuel andpower than is reasonable in the circumstancesThis requirement applies only to the work thathas actually been carried out eg if the workinvolves replacing windows there is no obligationon the contractor to provide details on theoperation of the heating system

72 Where the work involves the provision of anew heating system a way of complying wouldbe to provide a suitable set of operating andmaintenance instructions aimed at achievingeconomy in the use of fuel and power in termsthat householders can understand in a durableformat that can be kept and referred to over theservice life of the system(s) The instructionsshould be directly related to the particularsystem(s) installed as part of the work that hasbeen carried out

73 Without prejudice to the need to complywith health and safety requirements anyinstructions should explain to the occupier of thedwelling how to operate the system(s) efficientlyThis should include

a the making of adjustments to timingtemperature and flow control settings

b what routine maintenance is needed toenable operating efficiency to be maintainedat a reasonable level through the servicelive(s) of the system(s)

Section 7 Providing information

N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

Appendix A Work to thermal elements

1 Where work involves the renovation of athermal element an opportunity exists forcost-effective insulation improvements to beundertaken at marginal additional cost Thisappendix provides guidance on the cost-effectiveness of insulation measures whenundertaking various types of work on athermal element

2 Table A1 sets out the circumstances and thelevel of performance that would be consideredreasonable provision in ordinary circumstancesWhen dealing with existing dwellings someflexibility in the application of standards is necessaryto ensure that the context of each scheme canbe taken into account while securing as far aspossible the reasonable improvement The finalcolumn in Table A1 provides guidance on anumber of specific issues that may need to beconsidered in determining an appropriate courseof action As part of this flexible approach it willbe necessary to take into account technical riskand practicality in relation to the dwelling underconsideration and the possible impacts on anyadjoining building In general the proposed worksshould take account of

a the requirements of any other relevant partsof Schedule 1 to the Building Regulations

b the general guidance on technical risk relatingto insulation improvements contained inBR 26215

c for buildings falling within the categories setout in paragraphs 37 to 38 the guidanceproduced by English Heritage

Where it is not reasonable in the context of theworks project to achieve the performance set outin Table A1 the level of performance achievedshould be as close to this as practically possible

3 Table A1 incorporates in outline form examplesof construction that would achieve the proposedperformance but designers are free to use anyappropriate construction that satisfies the energyperformance standard so long as they do notcompromise performance with respect to any

other part of the Building Regulations4 General guidance is available from suchsources as the Energy Saving Trust and relevantBritish Standards

15 BR 262 Thermal insulation Avoiding risks BRE 2002

N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B WORK TO THERMAL ELEMENTS

Table A1 Cost-effective U-value targets when undertaking renovation works to

thermal elements

Proposed works Target U-value(Wm2K)

Typical construction Comments (reasonablenesspracticability and cost- effectiveness)

Pitched roof constructions16

Renewal of roof covering ndash No

living accommodation in the roofvoid ndash existing insulation (if any) atceiling level No existing insulationexisting insulation less than50 mm in poor condition andor likely to be significantlydisturbed or removed as partof the planned work

016 Provide loft insulation ndash

250 mm mineral fibre orcellulose fibre as quiltlaid between and acrossceiling joists or loose fill orequivalent

Assess condensation risk in roof space and

make appropriate provision in accordancewith the requirements of Part C relatingto the control of condensation Additionalprovision may be required to provide accessto and insulation of services in the roof void

Renewal of roof covering ndash Existinginsulation in good condition andwill not be significantly disturbedby proposed works Existinginsulation thickness 50 mm or morebut less than 100 mm

016 Top up loft insulation to atleast 250 mm mineral fibreor cellulose fibre as quiltlaid between and acrossceiling joists or loose fillor equivalent This may beboarded out

Assess condensation risk in roof space andmake appropriate provision in line with therequirements of Part C relating to the controlof condensation Additional provision maybe required to provide insulation and accessto services in the roof void

Where the loft is already boarded out and

the boarding is not to be removed as part ofthe work the practicality of insulation workswould need to be considered

Renewal of the ceiling to cold loftspace Existing insulation at ceilinglevel removed as part of the works

016 Provide loft insulation ndash250 mm mineral fibre orcellulose fibre as quiltlaid between and acrossceiling joists or loose fillor equivalent This may beboarded out

Assess condensation risk in roof space andmake appropriate provision in accordancewith the requirements of Part C relatingto the control of condensation Additionalprovision may be required to provide insulationand access to services in the roof void

Where the loft is already boarded out andthe boarding is not to be removed as partof the work insulation can be installed fromthe underside but the target U-value maynot be achievable

Renewal of roof covering ndashLiving accommodation in roofspace (room-in- the-roof typearrangement) with or withoutdormer windows

018 Cold structure ndash Insulation(thickness dependent onmaterial) placed betweenand below rafters

Warm structure ndash Insulationplaced between and aboverafters

Assess condensation risk (particularlyinterstitial condensation) and makeappropriate provision in accordance withthe requirements of Part C relating to thecontrol of condensation (Clause 84 ofBS 52502002 and BS EN ISO 137882002

Practical considerations with respect to anincrease in structural thickness (particularlyin terraced dwellings) may necessitate alower performance target

Dormer window constructions

Renewal of cladding to side walls 030 Insulation (thicknessdependent on material)placed between andor

fixed to outside of wallstuds Or fully externalto existing structuredepending on construction

Assess condensation risk and makeappropriate provision in accordance with therequirements of Part C

Renewal of roof covering ndash Follow guidance onimprovement to pitched orflat roofs as appropriate


E R I N

N L I N E V E R I N

8112019 Part L_Regs


WORK TO THERMAL ELEMENTS L1B

23


16 Specification of thickness of insulation is based on lambda values (conductivity) of 004 WmK


thermal elements



Flat roof constructions

Renewal of roof covering ndash Existing

insulation if any less than 100mm mineral fibre (or equivalentresistance) or in poor conditionand likely to be significantlydisturbed or removed as partof the planned work

018 Insulation placed between

and over joists as requiredto achieve the targetU-value ndash Warm structure

Assess condensation risk and make

appropriate provision in accordance withthe requirements of Part C Also see BS62292003 for design guidance

Renewal of the ceiling to flat roofarea Existing insulation removedas part of the works

018 Insulation placed betweenand to underside of joiststo achieve target U-value

Assess condensation risk and makeappropriate provision in accordance withthe requirements of Part C Also see BS62292003 for design guidance

Where ceiling height would be adverselyaffected a lower performance target may beappropriate

Solid wall constructions

Renewal of internal finish toexternal wall or applying a finish forthe first time

030 Dry-lining to inner face ofwall ndash insulation betweenstuds fixed to wall toachieve target U-value ndashthickness dependenton insulation and studmaterial used

Insulated wall board fixedto internal wall surfaceto achieve the requiredU-value ndash thicknessdependent on materialused

Assess the impact on internal floor area Ingeneral it would be reasonable to accept areduction of no more than 5 in the areaof a room However the use of the roomand the space requirements for movementand arrangements of fixtures fittings andfurniture should be assessed

In situations where acoustic attenuationissues are particularly important (egwhere insulation is returned at party walls)a less demanding U-value may be moreappropriate In such cases the U-valuetarget may have to be increased to 035 orabove depending on the circumstances

Assess condensation and other moisturerisks and make appropriate provision inaccordance with the requirements of PartC This will usually require the provision ofa vapour control and damp protection tocomponents Guidance on the risks involvedis provided in BR 262 and on the technicaloptions in Energy Saving Trust publications

Renewal of finish or cladding toexternal wall area or elevation(render or other cladding) orapplying a finish or cladding for thefirst time

030 External insulation systemwith rendered finish orcladding to give requiredU-value

Assess technical risk and impact ofincreased wall thickness on adjoiningbuildings

Ground floor constructions

Renovation of a solid or suspendedfloor involving the replacement ofscreed or a timber floor deck

See comment Solid floor ndash replace screedwith an insulated floor deckto maintain existing floorlevel

Suspended timber floor ndashfit insulation between floor joists prior to replacementof floor deck

The cost-effectiveness of floor insulation iscomplicated by the impact of the size andshape of the floor (perimeterarea ratio)In many cases existing un-insulated floorU-values are already relatively low whencompared with wall and roof U-valuesWhere the existing floor U-value is greaterthan 070 Wm2K then the addition ofinsulation is likely to be cost-effective Analysis shows that the costndashbenefit curvefor the thickness of added insulation is veryflat and so a target U-value of 025 Wm2Kis appropriate subject to other technicalconstraints (adjoining floor levels etc)

V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

BRE

wwwbrecouk

BR 262 Thermal insulation avoiding risks 2001ISBN 978 186081 515 7

BRE Report BR 443 Conventions for U-valuecalculations 2006 (Available at wwwbrecouk uvalues)

Department for Business

Innovation and Skills

wwwbisgovuk

Technical Standards and Regulations Directive9834EC (Available at wwwbisgovukpolicies innovationinfrastructureStandardisationtech-standards-directive)

Department for Energy andClimate Change (DECC)

wwwdeccgovuk

The Governmentrsquos Standard AssessmentProcedure for energy rating of dwellings SAP2009 (Available at wwwbrecouksap2009)

Current Energy Prices (wwwdeccgovuken contentcmsstatisticspublicationspricespricesaspx)

Department for Communities and

Local Government (DCLG)wwwcommunitiesgovuk

Accredited Construction Details for Part L (Available to download fromwwwplanningportalgovukengland professionalsen1115314255826html)

Energy Saving Trust (EST)

wwwestorguk

Energy Efficient Glazing ndash guidance(Available at wwwenergysavingtrustorguk

Home-improvements-and-productsHome-insulation-glazingGlazing)

English Heritage

wwwenglish-heritageorguk

Building Regulations and Historic Buildings 2002(revised 2004) and other guidance

Health and Safety Executive (HSE)

wwwhsegovuk

L24 Workplace Health Safety and Welfare

Workplace (Health Safety and Welfare)Regulations1992 Approved Code of Practiceand Guidance The Health and SafetyCommission 1992 ISBN 978 0 71760 413 5

NBS (on behalf of the Department

for Communities and Local

Government)

wwwthebuildingregscom

Domestic Building Services Compliance GuideDCLG 2010

Domestic Ventilation Compliance GuideDCLG 2010

(Both available to download from wwwplanningportalgovuk)

Legislation

Ancient Monuments and Archaeological Areas Act 1979

Listed Buildings and Conservation Areas) Act 1990

SI 19911620 Construction ProductsRegulations 1991

SI 19943051 Construction Products (Amendment)Regulations 1994

SI 19943260 Electrical Equipment (Safety)Regulations 1994

SI 20002214 The Building Regulations 2010

SI 20002215 The Building (Approved Inspectorsetc) Regulations 2010

SI 20063418 Electromagnetic Compatibility

Regulations 2006Decision No 195 of the EC-Turkey AssociationCouncil of 22 December 1995

Appendix B Documents referred to

N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

BS EN ISO 133702007 Thermal performance ofbuildings Heat transfer via the groundCalculation methods

BS EN 14351-12006 Windows and doors

Product standard performance characteristicsWindows and external pedestrian doorsetswithout resistance to fire andor smoke leakagecharacteristics

BS EN 4101998 Glass in building Determinationof luminous and solar characteristics of glazing

BS 6375-12009 Performance of windowsand doors Classification for weathertightnessand guidance on selection and specification

BS 52502002 Code of practice for controlof condensation in buildings

BS EN ISO 137882002 Hygrothermal

performance of building components andbuilding elements

BS 62292003 Flat roofs with continuouslysupported coverings Code of practice

Appendix C Standards referred to

N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

Index

A

Accredited construction detailsschemes 56

Airtightness 55 Ancient monuments 36 37 Approved Document L1B

Conventions 19Purpose 11ndash16Types of work covered 32ndash34

Architectural interest 38 Area-weighted U-value 45

B

BCBSee Building Control Body (BCB)

British Standards Appendix CBR 262 2002 Appendix A BS EN 14351 2006 420BS EN ISO 13370 410

Building Control Body (BCB)Definition 31

Notice of completion ofcommissioning 435ndash437Notification of work 317ndash318

Building fabricStandards 41See also Thermal elements

Building log book 72ndash73Building Regulations 21ndash24

Appendix BBuilding services

See Fixed building services

C

Cavity walls Table 3CE marking 327Certification

Competent person self-certificationschemes 319ndash322

Product certification schemes329ndash331

Change of energy status 412ndash415Change of use 411 415Cladding 57Commissioning

Definition 31Fixed building services 430ndash437

Common areas 336Competent person self-certification

schemes 319ndash322Compliance with requirements

12ndash13 111Materials and workmanship 327

331Self-certification 321

Consequential improvements 21 3161ndash65

Conservation areas 36 37Conservatories 315ndash316 48ndash49Controlled fittings 417ndash423 Table 1

Definition 31Controlled services 422 424ndash429

Definition 31

D

DERSee Dwelling CO

2 Emission Rate

(DER)Design flexibility 44ndash47 416Doors Table 1 42 48 415 419

Dormer windows Table A1Dry lining 57Dwelling

Definition 31Dwelling CO

2 Emission Rate (DER)

46ndash47

E

Emergency repairs 318Energy efficiency requirements 21

Compliance with 12ndash13 111Definition 31Exemptions 36Fixed building services 425ndash426

Energy performance

Consequential improvements 3161ndash65See also Dwelling CO

2 Emission Rate

(DER)Energy Performance Certificate

21ndash24Energy status change 412ndash415European standards 335European Technical Approval 327

334Exemptions 36Extensions 35 41ndash410

Consequential improvements 62Historic or traditional dwelling 311

F

FabricSee Building fabric

Fixed building services 424ndash427Commissioning 430ndash437Consequential improvements 62Definition 31Replacement 426System efficiencies 425ndash426See also Controlled services Heating

and hot water systems LightingFlat roofs 57 58 Table A1Floors

Upgrades Table 3U-values Table 2 Table A1

GGlazing

See Windows

H

Health and safety 336ndash337Heating and hot water systems

Commissioning 430ndash437Controls 48Extensions 43Non-notifiable work 324See also Fixed building services

Historic buildings 36ndash313

I

Independent certification schemes 329ndash331

Information provision 71ndash73Insulation

See Thermal insulation

Internal lighting 43

L

Legislation Appendix BEuropean 327See also Building Regulations

Lighting 43Limitation on requirements 22ndash24Listed buildings 36 37Low and zero carbon (LZC)

technologies 427 429

M

Maintenance instructions 72ndash73

Material change of use 411 415Materials and workmanship 326ndash328Minor works 323ndash325Mixed-use buildings 34Multiple dwellings 411

N

National parks 38Non-notifiable work 323ndash325Notice of completion of

commissioning 435ndash437Notification of work 317ndash318

O

Operating and maintenanceinstructions 72ndash73

P

Payback period 59 512Porches 315ndash316Product certification schemes

329ndash331Publications (excluding BSI and

European Standards) Appendix BConstruction Products Regulations

1991 (SI 19911620) 327Conventions for U-value calculations

(BR 443 2006) 420Domestic Building Services

Compliance Guide (DCLG 2010)424Domestic Ventilation Compliance

Guide (DCLG 2010) 433Electrical Equipment (Safety)

Regulations 1994 (SI 19943260)327

Electromagnetic CompatibilityRegulations 2006 (SI 20063418)327

N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



INDEX L1B

R

Rendering 57 58Renewable energy systems 427Renovation 33 47

Definition 31Historic and traditional buildings 312Thermal elements 51 57ndash510

Appendix A Table A1Replacement

Appliances 426ndash428Thermal elements 51 58Windows 419 423

Replacement windows 415Replastering 58Rooflights Table 1 421Roofs

Renovation 57 58Upgrades Table 3U-values Table 2 Table A1

Roof windows 42 48 415 419 421Table 1

Room for residential purposesDefinition 31

S

SAP 2009 46Self-certification schemes 319ndash322Simple payback 59 512

Definition 31Standard Assessment Procedure

(SAP 2009) 46Standards 332ndash335

See also British StandardsSwimming pools Table 2 410

T

Technical specifications 332ndash335Thermal bridges 55ndash56Thermal elements 51ndash513

Definition 31Renovation 57ndash510 Appendix A

Table A1Replacement 51 58Retained 511ndash513Upgrades 59 512ndash513 Table 3U-values 52ndash54

Thermal insulation 324 55ndash56 Appendix A

Thermal separation 48 49Traditional construction 38

U

Upgrades 47Thermal elements 59 512ndash513

Table 3

U-values 415 51 Table 2 Area-weighted 45Controlled fittings 419ndash423 Table 1Renovation targets Table A1

W

WallsUpgrades Table 3U-values Table 2 Table A1

Whole dwelling calculation method 46ndash47

Window Energy Rating (WER) 422Windows

Area of glazing 42

Conservatories and porches 48Replacement 415U-values 419ndash423 Table 1

Workmanship 326ndash328Workplace (Health Safety and

Welfare) Regulations 1992 336ndash337

N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs


APPROVED DOCUMENTSThe following documents have been approvedand issued by the First Secretary of State for thepurpose of providing practical guidance withrespect to the requirements of the BuildingRegulations 2010

Approved Document A Structure

2004 edition incorporating 2010 amendments Approved Document B (Fire safety) ndash Volume1 Dwellinghouses2006 edition incorporating 2010 amendments

Approved Document B (Fire safety) ndash Volume2 Buildings other than dwellinghouses2006 edition incorporating 2007 and 2010amendments

Approved Document C Site preparation andresistance to contaminants and moisture2004 edition incorporating 2010 amendments

Approved Document D Toxic substances1992 edition incorporating 2002 and 2010amendments

Approved Document E Resistance to thepassage of sound2003 edition incorporating 2004 and 2010amendments

Approved Document F Ventilation2010 edition incorporating further 2010 amendments

Approved Document G Sanitation hot watersafety and water efficiency2010 edition incorporating further 2010 amendments

Approved Document H Drainage and wastedisposal2002 edition incorporating 2010 amendments

Approved Document J Combustionappliances and fuel storage systems2010 edition incorporating further 2010 amendments

Approved Document K Protection from falling

collision and impact1998 edition incorporating 2000 and 2010amendments

Approved Document L1A Conservation offuel and power ndash New dwellings2010 edition incorporating further 2010 amendments

Approved Document L1B Conservation offuel and power ndash Existing dwellings2010 edition incorporating further 2010 and 2011amendments

Approved Document L2A Conservation offuel and power ndash New buildings other than

dwellings2010 edition incorporating further 2010 amendments

Approved Document L2B Conservation offuel and power ndash Existing buildings other thandwellings2010 edition incorporating further 2010 and 2011amendments

Approved Document M Access to and use ofbuildings2004 edition incorporating 2010 amendments

Approved Document N Glazing ndash safety inrelation to impact opening and cleaning

1998 edition incorporating 2000 and 2010amendments

Approved Document P Electrical safety ndashDwellings2006 edition incorporating 2010 amendments

Approved Document to support regulation 7Materials and workmanship1999 edition incorporating 2010 amendments

N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs


Published by NBS part of RIBA Enterprises Ltd and available from

RIBA Bookshops Mail Order

15 Bonhill Street

London EC2P 2EA

Telephone ordersGeneral enquiries 020 7256 7222

Fax orders 020 7374 2737

Email orders salesribabookshopscom

Or order online at

wwwthenbscombuildingregs

RIBA Bookshops

RIBA 66 Portland Place London WIB 1AD Telephone 020 7256 7222

Birmingham amp Midland Institute Margaret Street Birmingham B3 3SP Telephone 0121 233 2321

RSUA 2 Mount Charles Belfast BT7 1NZ Telephone 02890 323 760

CUBE 113-115 Portland Street Manchester M1 6DW Telephone 0161 236 7691

milkandsugar 82 Wood Street Liverpool L1 4DQ Telephone 0151 707 4380

ISBN 978 1 85946 325 3

Stock code 72233

copy Crown Copyright 2010

Reprint December 2010 with corrections

Copyright in the typographical arrangement rests with the Crown

This publication excluding logos may be reproduced free of charge in any formator medium for research private study or for internal circulation within anorganisation This is subject to it being reproduced accurately and not used in amisleading context The material must be acknowledged as Crown copyright andthe title of the publication specified This documentpublication is value addedIf you wish to re-use please apply for a Click-Use Licence for value addedmaterial at wwwopsigovukclick-usesystemonlinepLoginasp or by writing tothe Office of Public Sector Information Information Policy Team Kew RichmondSurrey TW9 4DU Email licensingopsigovuk If you require this publication inan alternative format please email alternativeformatscommunitiesgsigovuk

wwwthenbscom

B ui l d i n g

R e g ul at i o

n s 2 0 1 0

A P P R OV E D

D O C UME NT L 1 B

C o

n s er v a t i on of f u el an d p ow

er

N L I N E V E R I N

8112019 Part L_Regs


MAIN CHANGES IN THE

2010 EDITION1 This Approved Document L1B came into force

on 1 October 2010 in support of the Buildingand Approved Inspectors (Amendment)Regulations 2010 SI 2010 No 719 The mainchanges to the legal requirements and the

supporting guidance in this edition of Approved Document L1B are as follows

Changes in the legal requirements

2 The exemption from the energy efficiencyprovisions for extensions consisting of aconservatory or porch is amended to grantthe exemption only where any existing wallswindows or doors are retained or replaced ifremoved and where the heating system ofthe building is not extended into theconservatory or porch

3 The list of work in Schedule 4 (work thatneed not be notified to building control) isamended to include the installation ofthermal insulation in a roof space or loftspace where this is the only work carried outand the work is not carried out to complywith any requirement in the BuildingRegulations

Changes in the technical guidance

4 In this Approved Document the guidance isgenerally based upon an elemental approachto demonstrating compliance with additionalguidance that provides greater flexibility Themain technical changes comprise a generalstrengthening of energy efficiency standardsthat are considered reasonable for work onthermal elements controlled fittings andcontrolled services in existing dwellings

5 Amended guidance is given for historic andtraditional buildings which may have anexemption from the energy efficiencyrequirements or where special considerationsapply

6 Amended guidance is given where anextension is a conservatory or porch that isnot exempt from the energy efficiencyrequirements

7 The guidance for the renovation of a thermalelement through the provision of a new layeror through the replacement of an existinglayer has been expanded

8 Guidance is provided for swimming poolbasins (walls and floor) in existing dwellings

Main changes made by the

2010 and 2011 amendmentsThis 2010 edition incorporating the further2010 amendments reflects the changes madeas a result of the Building Regulations 2010Building Approved inspector etc Regulationsand the Building (Amendment) Regulations

2011 The changes mainly reflect regulationnumber changes as a result of re-ordering Therehave been no amendments to the substantiverequirements in Schedule 1(ie Parts A to P) ofthe Building Regulations

Please note the simplification of the definitionof lsquoroom for residential purposesrsquo in regulation2 of the Building Regulations 2010 and theamendment of the definition of ldquorenovationrdquoin regulation 2(1) of the Building (Amendment)Regulations 2011 Please also note that L1(c) hasnow become regulation 40

N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



PAGE










Key terms 7









Reference method 12












PAGE



U-values 17









Index 26


N L I N E V E R I N

8112019 Part L_Regs


L1B


2





























N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



INTRODUCTION L1B

















N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B









(i) of Schedule 1


Regulation 28




(a) an extension



building services




Schedule 1


















N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs














building and






building
















heating system or



(7) Wheremdash





dwellings

N L I N E V E R I N

8112019 Part L_Regs



6








building fabric and



















I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

Key terms



























i unconditioned



N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs










Approved Document































a listed buildings



I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



9

































L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



10





























1994 (SI 19943051)

I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



11





















L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B


Reference method

Fabric standards













design flexibility












are unknown








N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

































N L I N E V E R I N

8112019 Part L_Regs



14



flexibility





WORK ON CONTROLLED





Controlled fittings












Fitting Standard



16 Wm2


U-value = 18 Wm2K









Band A WER






Band G ndash70 WER

N

N L I N E V E R I N

8112019 Part L_Regs



15




Controlled services
















BUILDING SERVICES


44 Commissioning








I N

N L I N E V E R I N

8112019 Part L_Regs



16














N

N L I N E V E R I N

8112019 Part L_Regs



L1B





ELEMENTS






Wall 028




Floors3 0224


Notes






airtightness






ELEMENTS













N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





















Floor45 070 025












I N

N L I N E V E R I N

8112019 Part L_Regs



L1B



a an extension







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





thermal elements






























E R I N

N L I N E V E R I N

8112019 Part L_Regs



23




thermal elements





























V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

BRE

wwwbrecouk





wwwbisgovuk



wwwdeccgovuk







wwwestorguk



English Heritage




wwwhsegovuk





Government)





Legislation











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

Index

A





B









C













Definition 31

D

DERSee Dwelling CO

2 Emission Rate





46ndash47

E



Energy performance


2 Emission Rate





F





GGlazing

See Windows

H




I





L




M



N



O


P








Regulations 1994 (SI 19943260)327


N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



INDEX L1B

R









S





T






U


Table 3


W




Area of glazing 42




N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

























N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs




15 Bonhill Street

London EC2P 2EA


Fax orders 020 7374 2737


Or order online at


RIBA Bookshops






ISBN 978 1 85946 325 3

Stock code 72233





wwwthenbscom

B ui l d i n g

R e g ul at i o

n s 2 0 1 0

A P P R OV E D

D O C UME NT L 1 B

C o


er

N L I N E V E R I N

8112019 Part L_Regs



PAGE










Key terms 7









Reference method 12












PAGE



U-values 17









Index 26


N L I N E V E R I N

8112019 Part L_Regs


L1B


2





























N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



INTRODUCTION L1B

















N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B









(i) of Schedule 1


Regulation 28




(a) an extension



building services




Schedule 1


















N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs














building and






building
















heating system or



(7) Wheremdash





dwellings

N L I N E V E R I N

8112019 Part L_Regs



6








building fabric and



















I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

Key terms



























i unconditioned



N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs










Approved Document































a listed buildings



I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



9

































L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



10





























1994 (SI 19943051)

I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



11





















L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B


Reference method

Fabric standards













design flexibility












are unknown








N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

































N L I N E V E R I N

8112019 Part L_Regs



14



flexibility





WORK ON CONTROLLED





Controlled fittings












Fitting Standard



16 Wm2


U-value = 18 Wm2K









Band A WER






Band G ndash70 WER

N

N L I N E V E R I N

8112019 Part L_Regs



15




Controlled services
















BUILDING SERVICES


44 Commissioning








I N

N L I N E V E R I N

8112019 Part L_Regs



16














N

N L I N E V E R I N

8112019 Part L_Regs



L1B





ELEMENTS






Wall 028




Floors3 0224


Notes






airtightness






ELEMENTS













N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





















Floor45 070 025












I N

N L I N E V E R I N

8112019 Part L_Regs



L1B



a an extension







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





thermal elements






























E R I N

N L I N E V E R I N

8112019 Part L_Regs



23




thermal elements





























V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

BRE

wwwbrecouk





wwwbisgovuk



wwwdeccgovuk







wwwestorguk



English Heritage




wwwhsegovuk





Government)





Legislation











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

Index

A





B









C













Definition 31

D

DERSee Dwelling CO

2 Emission Rate





46ndash47

E



Energy performance


2 Emission Rate





F





GGlazing

See Windows

H




I





L




M



N



O


P








Regulations 1994 (SI 19943260)327


N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



INDEX L1B

R









S





T






U


Table 3


W




Area of glazing 42




N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

























N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs




15 Bonhill Street

London EC2P 2EA


Fax orders 020 7374 2737


Or order online at


RIBA Bookshops






ISBN 978 1 85946 325 3

Stock code 72233





wwwthenbscom

B ui l d i n g

R e g ul at i o

n s 2 0 1 0

A P P R OV E D

D O C UME NT L 1 B

C o


er

N L I N E V E R I N

8112019 Part L_Regs


L1B


2





























N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



INTRODUCTION L1B

















N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B









(i) of Schedule 1


Regulation 28




(a) an extension



building services




Schedule 1


















N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs














building and






building
















heating system or



(7) Wheremdash





dwellings

N L I N E V E R I N

8112019 Part L_Regs



6








building fabric and



















I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

Key terms



























i unconditioned



N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs










Approved Document































a listed buildings



I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



9

































L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



10





























1994 (SI 19943051)

I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



11





















L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B


Reference method

Fabric standards













design flexibility












are unknown








N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

































N L I N E V E R I N

8112019 Part L_Regs



14



flexibility





WORK ON CONTROLLED





Controlled fittings












Fitting Standard



16 Wm2


U-value = 18 Wm2K









Band A WER






Band G ndash70 WER

N

N L I N E V E R I N

8112019 Part L_Regs



15




Controlled services
















BUILDING SERVICES


44 Commissioning








I N

N L I N E V E R I N

8112019 Part L_Regs



16














N

N L I N E V E R I N

8112019 Part L_Regs



L1B





ELEMENTS






Wall 028




Floors3 0224


Notes






airtightness






ELEMENTS













N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





















Floor45 070 025












I N

N L I N E V E R I N

8112019 Part L_Regs



L1B



a an extension







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





thermal elements






























E R I N

N L I N E V E R I N

8112019 Part L_Regs



23




thermal elements





























V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

BRE

wwwbrecouk





wwwbisgovuk



wwwdeccgovuk







wwwestorguk



English Heritage




wwwhsegovuk





Government)





Legislation











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

Index

A





B









C













Definition 31

D

DERSee Dwelling CO

2 Emission Rate





46ndash47

E



Energy performance


2 Emission Rate





F





GGlazing

See Windows

H




I





L




M



N



O


P








Regulations 1994 (SI 19943260)327


N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



INDEX L1B

R









S





T






U


Table 3


W




Area of glazing 42




N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

























N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs




15 Bonhill Street

London EC2P 2EA


Fax orders 020 7374 2737


Or order online at


RIBA Bookshops






ISBN 978 1 85946 325 3

Stock code 72233





wwwthenbscom

B ui l d i n g

R e g ul at i o

n s 2 0 1 0

A P P R OV E D

D O C UME NT L 1 B

C o


er

N L I N E V E R I N

8112019 Part L_Regs



INTRODUCTION L1B

















N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B









(i) of Schedule 1


Regulation 28




(a) an extension



building services




Schedule 1


















N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs














building and






building
















heating system or



(7) Wheremdash





dwellings

N L I N E V E R I N

8112019 Part L_Regs



6








building fabric and



















I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

Key terms



























i unconditioned



N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs










Approved Document































a listed buildings



I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



9

































L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



10





























1994 (SI 19943051)

I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



11





















L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B


Reference method

Fabric standards













design flexibility












are unknown








N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

































N L I N E V E R I N

8112019 Part L_Regs



14



flexibility





WORK ON CONTROLLED





Controlled fittings












Fitting Standard



16 Wm2


U-value = 18 Wm2K









Band A WER






Band G ndash70 WER

N

N L I N E V E R I N

8112019 Part L_Regs



15




Controlled services
















BUILDING SERVICES


44 Commissioning








I N

N L I N E V E R I N

8112019 Part L_Regs



16














N

N L I N E V E R I N

8112019 Part L_Regs



L1B





ELEMENTS






Wall 028




Floors3 0224


Notes






airtightness






ELEMENTS













N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





















Floor45 070 025












I N

N L I N E V E R I N

8112019 Part L_Regs



L1B



a an extension







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





thermal elements






























E R I N

N L I N E V E R I N

8112019 Part L_Regs



23




thermal elements





























V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

BRE

wwwbrecouk





wwwbisgovuk



wwwdeccgovuk







wwwestorguk



English Heritage




wwwhsegovuk





Government)





Legislation











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

Index

A





B









C













Definition 31

D

DERSee Dwelling CO

2 Emission Rate





46ndash47

E



Energy performance


2 Emission Rate





F





GGlazing

See Windows

H




I





L




M



N



O


P








Regulations 1994 (SI 19943260)327


N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



INDEX L1B

R









S





T






U


Table 3


W




Area of glazing 42




N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

























N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs




15 Bonhill Street

London EC2P 2EA


Fax orders 020 7374 2737


Or order online at


RIBA Bookshops






ISBN 978 1 85946 325 3

Stock code 72233





wwwthenbscom

B ui l d i n g

R e g ul at i o

n s 2 0 1 0

A P P R OV E D

D O C UME NT L 1 B

C o


er

N L I N E V E R I N

8112019 Part L_Regs



L1B









(i) of Schedule 1


Regulation 28




(a) an extension



building services




Schedule 1


















N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs














building and






building
















heating system or



(7) Wheremdash





dwellings

N L I N E V E R I N

8112019 Part L_Regs



6








building fabric and



















I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

Key terms



























i unconditioned



N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs










Approved Document































a listed buildings



I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



9

































L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



10





























1994 (SI 19943051)

I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



11





















L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B


Reference method

Fabric standards













design flexibility












are unknown








N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

































N L I N E V E R I N

8112019 Part L_Regs



14



flexibility





WORK ON CONTROLLED





Controlled fittings












Fitting Standard



16 Wm2


U-value = 18 Wm2K









Band A WER






Band G ndash70 WER

N

N L I N E V E R I N

8112019 Part L_Regs



15




Controlled services
















BUILDING SERVICES


44 Commissioning








I N

N L I N E V E R I N

8112019 Part L_Regs



16














N

N L I N E V E R I N

8112019 Part L_Regs



L1B





ELEMENTS






Wall 028




Floors3 0224


Notes






airtightness






ELEMENTS













N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





















Floor45 070 025












I N

N L I N E V E R I N

8112019 Part L_Regs



L1B



a an extension







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





thermal elements






























E R I N

N L I N E V E R I N

8112019 Part L_Regs



23




thermal elements





























V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

BRE

wwwbrecouk





wwwbisgovuk



wwwdeccgovuk







wwwestorguk



English Heritage




wwwhsegovuk





Government)





Legislation











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

Index

A





B









C













Definition 31

D

DERSee Dwelling CO

2 Emission Rate





46ndash47

E



Energy performance


2 Emission Rate





F





GGlazing

See Windows

H




I





L




M



N



O


P








Regulations 1994 (SI 19943260)327


N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



INDEX L1B

R









S





T






U


Table 3


W




Area of glazing 42




N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

























N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs




15 Bonhill Street

London EC2P 2EA


Fax orders 020 7374 2737


Or order online at


RIBA Bookshops






ISBN 978 1 85946 325 3

Stock code 72233





wwwthenbscom

B ui l d i n g

R e g ul at i o

n s 2 0 1 0

A P P R OV E D

D O C UME NT L 1 B

C o


er

N L I N E V E R I N

8112019 Part L_Regs














building and






building
















heating system or



(7) Wheremdash





dwellings

N L I N E V E R I N

8112019 Part L_Regs



6








building fabric and



















I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

Key terms



























i unconditioned



N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs










Approved Document































a listed buildings



I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



9

































L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



10





























1994 (SI 19943051)

I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



11





















L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B


Reference method

Fabric standards













design flexibility












are unknown








N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

































N L I N E V E R I N

8112019 Part L_Regs



14



flexibility





WORK ON CONTROLLED





Controlled fittings












Fitting Standard



16 Wm2


U-value = 18 Wm2K









Band A WER






Band G ndash70 WER

N

N L I N E V E R I N

8112019 Part L_Regs



15




Controlled services
















BUILDING SERVICES


44 Commissioning








I N

N L I N E V E R I N

8112019 Part L_Regs



16














N

N L I N E V E R I N

8112019 Part L_Regs



L1B





ELEMENTS






Wall 028




Floors3 0224


Notes






airtightness






ELEMENTS













N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





















Floor45 070 025












I N

N L I N E V E R I N

8112019 Part L_Regs



L1B



a an extension







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





thermal elements






























E R I N

N L I N E V E R I N

8112019 Part L_Regs



23




thermal elements





























V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

BRE

wwwbrecouk





wwwbisgovuk



wwwdeccgovuk







wwwestorguk



English Heritage




wwwhsegovuk





Government)





Legislation











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

Index

A





B









C













Definition 31

D

DERSee Dwelling CO

2 Emission Rate





46ndash47

E



Energy performance


2 Emission Rate





F





GGlazing

See Windows

H




I





L




M



N



O


P








Regulations 1994 (SI 19943260)327


N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



INDEX L1B

R









S





T






U


Table 3


W




Area of glazing 42




N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

























N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs




15 Bonhill Street

London EC2P 2EA


Fax orders 020 7374 2737


Or order online at


RIBA Bookshops






ISBN 978 1 85946 325 3

Stock code 72233





wwwthenbscom

B ui l d i n g

R e g ul at i o

n s 2 0 1 0

A P P R OV E D

D O C UME NT L 1 B

C o


er

N L I N E V E R I N

8112019 Part L_Regs



6








building fabric and



















I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

Key terms



























i unconditioned



N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs










Approved Document































a listed buildings



I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



9

































L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



10





























1994 (SI 19943051)

I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



11





















L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B


Reference method

Fabric standards













design flexibility












are unknown








N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

































N L I N E V E R I N

8112019 Part L_Regs



14



flexibility





WORK ON CONTROLLED





Controlled fittings












Fitting Standard



16 Wm2


U-value = 18 Wm2K









Band A WER






Band G ndash70 WER

N

N L I N E V E R I N

8112019 Part L_Regs



15




Controlled services
















BUILDING SERVICES


44 Commissioning








I N

N L I N E V E R I N

8112019 Part L_Regs



16














N

N L I N E V E R I N

8112019 Part L_Regs



L1B





ELEMENTS






Wall 028




Floors3 0224


Notes






airtightness






ELEMENTS













N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





















Floor45 070 025












I N

N L I N E V E R I N

8112019 Part L_Regs



L1B



a an extension







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





thermal elements






























E R I N

N L I N E V E R I N

8112019 Part L_Regs



23




thermal elements





























V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

BRE

wwwbrecouk





wwwbisgovuk



wwwdeccgovuk







wwwestorguk



English Heritage




wwwhsegovuk





Government)





Legislation











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

Index

A





B









C













Definition 31

D

DERSee Dwelling CO

2 Emission Rate





46ndash47

E



Energy performance


2 Emission Rate





F





GGlazing

See Windows

H




I





L




M



N



O


P








Regulations 1994 (SI 19943260)327


N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



INDEX L1B

R









S





T






U


Table 3


W




Area of glazing 42




N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

























N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs




15 Bonhill Street

London EC2P 2EA


Fax orders 020 7374 2737


Or order online at


RIBA Bookshops






ISBN 978 1 85946 325 3

Stock code 72233





wwwthenbscom

B ui l d i n g

R e g ul at i o

n s 2 0 1 0

A P P R OV E D

D O C UME NT L 1 B

C o


er

N L I N E V E R I N

8112019 Part L_Regs



L1B

Key terms



























i unconditioned



N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs










Approved Document































a listed buildings



I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



9

































L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



10





























1994 (SI 19943051)

I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



11





















L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B


Reference method

Fabric standards













design flexibility












are unknown








N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

































N L I N E V E R I N

8112019 Part L_Regs



14



flexibility





WORK ON CONTROLLED





Controlled fittings












Fitting Standard



16 Wm2


U-value = 18 Wm2K









Band A WER






Band G ndash70 WER

N

N L I N E V E R I N

8112019 Part L_Regs



15




Controlled services
















BUILDING SERVICES


44 Commissioning








I N

N L I N E V E R I N

8112019 Part L_Regs



16














N

N L I N E V E R I N

8112019 Part L_Regs



L1B





ELEMENTS






Wall 028




Floors3 0224


Notes






airtightness






ELEMENTS













N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





















Floor45 070 025












I N

N L I N E V E R I N

8112019 Part L_Regs



L1B



a an extension







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





thermal elements






























E R I N

N L I N E V E R I N

8112019 Part L_Regs



23




thermal elements





























V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

BRE

wwwbrecouk





wwwbisgovuk



wwwdeccgovuk







wwwestorguk



English Heritage




wwwhsegovuk





Government)





Legislation











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

Index

A





B









C













Definition 31

D

DERSee Dwelling CO

2 Emission Rate





46ndash47

E



Energy performance


2 Emission Rate





F





GGlazing

See Windows

H




I





L




M



N



O


P








Regulations 1994 (SI 19943260)327


N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



INDEX L1B

R









S





T






U


Table 3


W




Area of glazing 42




N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

























N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs




15 Bonhill Street

London EC2P 2EA


Fax orders 020 7374 2737


Or order online at


RIBA Bookshops






ISBN 978 1 85946 325 3

Stock code 72233





wwwthenbscom

B ui l d i n g

R e g ul at i o

n s 2 0 1 0

A P P R OV E D

D O C UME NT L 1 B

C o


er

N L I N E V E R I N

8112019 Part L_Regs










Approved Document































a listed buildings



I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



9

































L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



10





























1994 (SI 19943051)

I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



11





















L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B


Reference method

Fabric standards













design flexibility












are unknown








N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

































N L I N E V E R I N

8112019 Part L_Regs



14



flexibility





WORK ON CONTROLLED





Controlled fittings












Fitting Standard



16 Wm2


U-value = 18 Wm2K









Band A WER






Band G ndash70 WER

N

N L I N E V E R I N

8112019 Part L_Regs



15




Controlled services
















BUILDING SERVICES


44 Commissioning








I N

N L I N E V E R I N

8112019 Part L_Regs



16














N

N L I N E V E R I N

8112019 Part L_Regs



L1B





ELEMENTS






Wall 028




Floors3 0224


Notes






airtightness






ELEMENTS













N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





















Floor45 070 025












I N

N L I N E V E R I N

8112019 Part L_Regs



L1B



a an extension







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





thermal elements






























E R I N

N L I N E V E R I N

8112019 Part L_Regs



23




thermal elements





























V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

BRE

wwwbrecouk





wwwbisgovuk



wwwdeccgovuk







wwwestorguk



English Heritage




wwwhsegovuk





Government)





Legislation











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

Index

A





B









C













Definition 31

D

DERSee Dwelling CO

2 Emission Rate





46ndash47

E



Energy performance


2 Emission Rate





F





GGlazing

See Windows

H




I





L




M



N



O


P








Regulations 1994 (SI 19943260)327


N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



INDEX L1B

R









S





T






U


Table 3


W




Area of glazing 42




N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

























N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs




15 Bonhill Street

London EC2P 2EA


Fax orders 020 7374 2737


Or order online at


RIBA Bookshops






ISBN 978 1 85946 325 3

Stock code 72233





wwwthenbscom

B ui l d i n g

R e g ul at i o

n s 2 0 1 0

A P P R OV E D

D O C UME NT L 1 B

C o


er

N L I N E V E R I N

8112019 Part L_Regs



9

































L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



10





























1994 (SI 19943051)

I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



11





















L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B


Reference method

Fabric standards













design flexibility












are unknown








N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

































N L I N E V E R I N

8112019 Part L_Regs



14



flexibility





WORK ON CONTROLLED





Controlled fittings












Fitting Standard



16 Wm2


U-value = 18 Wm2K









Band A WER






Band G ndash70 WER

N

N L I N E V E R I N

8112019 Part L_Regs



15




Controlled services
















BUILDING SERVICES


44 Commissioning








I N

N L I N E V E R I N

8112019 Part L_Regs



16














N

N L I N E V E R I N

8112019 Part L_Regs



L1B





ELEMENTS






Wall 028




Floors3 0224


Notes






airtightness






ELEMENTS













N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





















Floor45 070 025












I N

N L I N E V E R I N

8112019 Part L_Regs



L1B



a an extension







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





thermal elements






























E R I N

N L I N E V E R I N

8112019 Part L_Regs



23




thermal elements





























V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

BRE

wwwbrecouk





wwwbisgovuk



wwwdeccgovuk







wwwestorguk



English Heritage




wwwhsegovuk





Government)





Legislation











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

Index

A





B









C













Definition 31

D

DERSee Dwelling CO

2 Emission Rate





46ndash47

E



Energy performance


2 Emission Rate





F





GGlazing

See Windows

H




I





L




M



N



O


P








Regulations 1994 (SI 19943260)327


N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



INDEX L1B

R









S





T






U


Table 3


W




Area of glazing 42




N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

























N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs




15 Bonhill Street

London EC2P 2EA


Fax orders 020 7374 2737


Or order online at


RIBA Bookshops






ISBN 978 1 85946 325 3

Stock code 72233





wwwthenbscom

B ui l d i n g

R e g ul at i o

n s 2 0 1 0

A P P R OV E D

D O C UME NT L 1 B

C o


er

N L I N E V E R I N

8112019 Part L_Regs



10





























1994 (SI 19943051)

I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



11





















L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B


Reference method

Fabric standards













design flexibility












are unknown








N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

































N L I N E V E R I N

8112019 Part L_Regs



14



flexibility





WORK ON CONTROLLED





Controlled fittings












Fitting Standard



16 Wm2


U-value = 18 Wm2K









Band A WER






Band G ndash70 WER

N

N L I N E V E R I N

8112019 Part L_Regs



15




Controlled services
















BUILDING SERVICES


44 Commissioning








I N

N L I N E V E R I N

8112019 Part L_Regs



16














N

N L I N E V E R I N

8112019 Part L_Regs



L1B





ELEMENTS






Wall 028




Floors3 0224


Notes






airtightness






ELEMENTS













N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





















Floor45 070 025












I N

N L I N E V E R I N

8112019 Part L_Regs



L1B



a an extension







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





thermal elements






























E R I N

N L I N E V E R I N

8112019 Part L_Regs



23




thermal elements





























V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

BRE

wwwbrecouk





wwwbisgovuk



wwwdeccgovuk







wwwestorguk



English Heritage




wwwhsegovuk





Government)





Legislation











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

Index

A





B









C













Definition 31

D

DERSee Dwelling CO

2 Emission Rate





46ndash47

E



Energy performance


2 Emission Rate





F





GGlazing

See Windows

H




I





L




M



N



O


P








Regulations 1994 (SI 19943260)327


N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



INDEX L1B

R









S





T






U


Table 3


W




Area of glazing 42




N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

























N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs




15 Bonhill Street

London EC2P 2EA


Fax orders 020 7374 2737


Or order online at


RIBA Bookshops






ISBN 978 1 85946 325 3

Stock code 72233





wwwthenbscom

B ui l d i n g

R e g ul at i o

n s 2 0 1 0

A P P R OV E D

D O C UME NT L 1 B

C o


er

N L I N E V E R I N

8112019 Part L_Regs



11





















L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B


Reference method

Fabric standards













design flexibility












are unknown








N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

































N L I N E V E R I N

8112019 Part L_Regs



14



flexibility





WORK ON CONTROLLED





Controlled fittings












Fitting Standard



16 Wm2


U-value = 18 Wm2K









Band A WER






Band G ndash70 WER

N

N L I N E V E R I N

8112019 Part L_Regs



15




Controlled services
















BUILDING SERVICES


44 Commissioning








I N

N L I N E V E R I N

8112019 Part L_Regs



16














N

N L I N E V E R I N

8112019 Part L_Regs



L1B





ELEMENTS






Wall 028




Floors3 0224


Notes






airtightness






ELEMENTS













N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





















Floor45 070 025












I N

N L I N E V E R I N

8112019 Part L_Regs



L1B



a an extension







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





thermal elements






























E R I N

N L I N E V E R I N

8112019 Part L_Regs



23




thermal elements





























V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

BRE

wwwbrecouk





wwwbisgovuk



wwwdeccgovuk







wwwestorguk



English Heritage




wwwhsegovuk





Government)





Legislation











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

Index

A





B









C













Definition 31

D

DERSee Dwelling CO

2 Emission Rate





46ndash47

E



Energy performance


2 Emission Rate





F





GGlazing

See Windows

H




I





L




M



N



O


P








Regulations 1994 (SI 19943260)327


N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



INDEX L1B

R









S





T






U


Table 3


W




Area of glazing 42




N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

























N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs




15 Bonhill Street

London EC2P 2EA


Fax orders 020 7374 2737


Or order online at


RIBA Bookshops






ISBN 978 1 85946 325 3

Stock code 72233





wwwthenbscom

B ui l d i n g

R e g ul at i o

n s 2 0 1 0

A P P R OV E D

D O C UME NT L 1 B

C o


er

N L I N E V E R I N

8112019 Part L_Regs



L1B


Reference method

Fabric standards













design flexibility












are unknown








N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

































N L I N E V E R I N

8112019 Part L_Regs



14



flexibility





WORK ON CONTROLLED





Controlled fittings












Fitting Standard



16 Wm2


U-value = 18 Wm2K









Band A WER






Band G ndash70 WER

N

N L I N E V E R I N

8112019 Part L_Regs



15




Controlled services
















BUILDING SERVICES


44 Commissioning








I N

N L I N E V E R I N

8112019 Part L_Regs



16














N

N L I N E V E R I N

8112019 Part L_Regs



L1B





ELEMENTS






Wall 028




Floors3 0224


Notes






airtightness






ELEMENTS













N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





















Floor45 070 025












I N

N L I N E V E R I N

8112019 Part L_Regs



L1B



a an extension







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





thermal elements






























E R I N

N L I N E V E R I N

8112019 Part L_Regs



23




thermal elements





























V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

BRE

wwwbrecouk





wwwbisgovuk



wwwdeccgovuk







wwwestorguk



English Heritage




wwwhsegovuk





Government)





Legislation











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

Index

A





B









C













Definition 31

D

DERSee Dwelling CO

2 Emission Rate





46ndash47

E



Energy performance


2 Emission Rate





F





GGlazing

See Windows

H




I





L




M



N



O


P








Regulations 1994 (SI 19943260)327


N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



INDEX L1B

R









S





T






U


Table 3


W




Area of glazing 42




N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

























N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs




15 Bonhill Street

London EC2P 2EA


Fax orders 020 7374 2737


Or order online at


RIBA Bookshops






ISBN 978 1 85946 325 3

Stock code 72233





wwwthenbscom

B ui l d i n g

R e g ul at i o

n s 2 0 1 0

A P P R OV E D

D O C UME NT L 1 B

C o


er

N L I N E V E R I N

8112019 Part L_Regs

































N L I N E V E R I N

8112019 Part L_Regs



14



flexibility





WORK ON CONTROLLED





Controlled fittings












Fitting Standard



16 Wm2


U-value = 18 Wm2K









Band A WER






Band G ndash70 WER

N

N L I N E V E R I N

8112019 Part L_Regs



15




Controlled services
















BUILDING SERVICES


44 Commissioning








I N

N L I N E V E R I N

8112019 Part L_Regs



16














N

N L I N E V E R I N

8112019 Part L_Regs



L1B





ELEMENTS






Wall 028




Floors3 0224


Notes






airtightness






ELEMENTS













N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





















Floor45 070 025












I N

N L I N E V E R I N

8112019 Part L_Regs



L1B



a an extension







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





thermal elements






























E R I N

N L I N E V E R I N

8112019 Part L_Regs



23




thermal elements





























V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

BRE

wwwbrecouk





wwwbisgovuk



wwwdeccgovuk







wwwestorguk



English Heritage




wwwhsegovuk





Government)





Legislation











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

Index

A





B









C













Definition 31

D

DERSee Dwelling CO

2 Emission Rate





46ndash47

E



Energy performance


2 Emission Rate





F





GGlazing

See Windows

H




I





L




M



N



O


P








Regulations 1994 (SI 19943260)327


N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



INDEX L1B

R









S





T






U


Table 3


W




Area of glazing 42




N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

























N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs




15 Bonhill Street

London EC2P 2EA


Fax orders 020 7374 2737


Or order online at


RIBA Bookshops






ISBN 978 1 85946 325 3

Stock code 72233





wwwthenbscom

B ui l d i n g

R e g ul at i o

n s 2 0 1 0

A P P R OV E D

D O C UME NT L 1 B

C o


er

N L I N E V E R I N

8112019 Part L_Regs



14



flexibility





WORK ON CONTROLLED





Controlled fittings












Fitting Standard



16 Wm2


U-value = 18 Wm2K









Band A WER






Band G ndash70 WER

N

N L I N E V E R I N

8112019 Part L_Regs



15




Controlled services
















BUILDING SERVICES


44 Commissioning








I N

N L I N E V E R I N

8112019 Part L_Regs



16














N

N L I N E V E R I N

8112019 Part L_Regs



L1B





ELEMENTS






Wall 028




Floors3 0224


Notes






airtightness






ELEMENTS













N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





















Floor45 070 025












I N

N L I N E V E R I N

8112019 Part L_Regs



L1B



a an extension







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





thermal elements






























E R I N

N L I N E V E R I N

8112019 Part L_Regs



23




thermal elements





























V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

BRE

wwwbrecouk





wwwbisgovuk



wwwdeccgovuk







wwwestorguk



English Heritage




wwwhsegovuk





Government)





Legislation











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

Index

A





B









C













Definition 31

D

DERSee Dwelling CO

2 Emission Rate





46ndash47

E



Energy performance


2 Emission Rate





F





GGlazing

See Windows

H




I





L




M



N



O


P








Regulations 1994 (SI 19943260)327


N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



INDEX L1B

R









S





T






U


Table 3


W




Area of glazing 42




N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

























N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs




15 Bonhill Street

London EC2P 2EA


Fax orders 020 7374 2737


Or order online at


RIBA Bookshops






ISBN 978 1 85946 325 3

Stock code 72233





wwwthenbscom

B ui l d i n g

R e g ul at i o

n s 2 0 1 0

A P P R OV E D

D O C UME NT L 1 B

C o


er

N L I N E V E R I N

8112019 Part L_Regs



15




Controlled services
















BUILDING SERVICES


44 Commissioning








I N

N L I N E V E R I N

8112019 Part L_Regs



16














N

N L I N E V E R I N

8112019 Part L_Regs



L1B





ELEMENTS






Wall 028




Floors3 0224


Notes






airtightness






ELEMENTS













N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





















Floor45 070 025












I N

N L I N E V E R I N

8112019 Part L_Regs



L1B



a an extension







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





thermal elements






























E R I N

N L I N E V E R I N

8112019 Part L_Regs



23




thermal elements





























V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

BRE

wwwbrecouk





wwwbisgovuk



wwwdeccgovuk







wwwestorguk



English Heritage




wwwhsegovuk





Government)





Legislation











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

Index

A





B









C













Definition 31

D

DERSee Dwelling CO

2 Emission Rate





46ndash47

E



Energy performance


2 Emission Rate





F





GGlazing

See Windows

H




I





L




M



N



O


P








Regulations 1994 (SI 19943260)327


N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



INDEX L1B

R









S





T






U


Table 3


W




Area of glazing 42




N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

























N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs




15 Bonhill Street

London EC2P 2EA


Fax orders 020 7374 2737


Or order online at


RIBA Bookshops






ISBN 978 1 85946 325 3

Stock code 72233





wwwthenbscom

B ui l d i n g

R e g ul at i o

n s 2 0 1 0

A P P R OV E D

D O C UME NT L 1 B

C o


er

N L I N E V E R I N

8112019 Part L_Regs



16














N

N L I N E V E R I N

8112019 Part L_Regs



L1B





ELEMENTS






Wall 028




Floors3 0224


Notes






airtightness






ELEMENTS













N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





















Floor45 070 025












I N

N L I N E V E R I N

8112019 Part L_Regs



L1B



a an extension







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





thermal elements






























E R I N

N L I N E V E R I N

8112019 Part L_Regs



23




thermal elements





























V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

BRE

wwwbrecouk





wwwbisgovuk



wwwdeccgovuk







wwwestorguk



English Heritage




wwwhsegovuk





Government)





Legislation











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

Index

A





B









C













Definition 31

D

DERSee Dwelling CO

2 Emission Rate





46ndash47

E



Energy performance


2 Emission Rate





F





GGlazing

See Windows

H




I





L




M



N



O


P








Regulations 1994 (SI 19943260)327


N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



INDEX L1B

R









S





T






U


Table 3


W




Area of glazing 42




N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

























N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs




15 Bonhill Street

London EC2P 2EA


Fax orders 020 7374 2737


Or order online at


RIBA Bookshops






ISBN 978 1 85946 325 3

Stock code 72233





wwwthenbscom

B ui l d i n g

R e g ul at i o

n s 2 0 1 0

A P P R OV E D

D O C UME NT L 1 B

C o


er

N L I N E V E R I N

8112019 Part L_Regs



L1B





ELEMENTS






Wall 028




Floors3 0224


Notes






airtightness






ELEMENTS













N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





















Floor45 070 025












I N

N L I N E V E R I N

8112019 Part L_Regs



L1B



a an extension







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





thermal elements






























E R I N

N L I N E V E R I N

8112019 Part L_Regs



23




thermal elements





























V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

BRE

wwwbrecouk





wwwbisgovuk



wwwdeccgovuk







wwwestorguk



English Heritage




wwwhsegovuk





Government)





Legislation











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

Index

A





B









C













Definition 31

D

DERSee Dwelling CO

2 Emission Rate





46ndash47

E



Energy performance


2 Emission Rate





F





GGlazing

See Windows

H




I





L




M



N



O


P








Regulations 1994 (SI 19943260)327


N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



INDEX L1B

R









S





T






U


Table 3


W




Area of glazing 42




N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

























N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs




15 Bonhill Street

London EC2P 2EA


Fax orders 020 7374 2737


Or order online at


RIBA Bookshops






ISBN 978 1 85946 325 3

Stock code 72233





wwwthenbscom

B ui l d i n g

R e g ul at i o

n s 2 0 1 0

A P P R OV E D

D O C UME NT L 1 B

C o


er

N L I N E V E R I N

8112019 Part L_Regs





















Floor45 070 025












I N

N L I N E V E R I N

8112019 Part L_Regs



L1B



a an extension







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





thermal elements






























E R I N

N L I N E V E R I N

8112019 Part L_Regs



23




thermal elements





























V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

BRE

wwwbrecouk





wwwbisgovuk



wwwdeccgovuk







wwwestorguk



English Heritage




wwwhsegovuk





Government)





Legislation











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

Index

A





B









C













Definition 31

D

DERSee Dwelling CO

2 Emission Rate





46ndash47

E



Energy performance


2 Emission Rate





F





GGlazing

See Windows

H




I





L




M



N



O


P








Regulations 1994 (SI 19943260)327


N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



INDEX L1B

R









S





T






U


Table 3


W




Area of glazing 42




N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

























N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs




15 Bonhill Street

London EC2P 2EA


Fax orders 020 7374 2737


Or order online at


RIBA Bookshops






ISBN 978 1 85946 325 3

Stock code 72233





wwwthenbscom

B ui l d i n g

R e g ul at i o

n s 2 0 1 0

A P P R OV E D

D O C UME NT L 1 B

C o


er

N L I N E V E R I N

8112019 Part L_Regs



L1B



a an extension







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





thermal elements






























E R I N

N L I N E V E R I N

8112019 Part L_Regs



23




thermal elements





























V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

BRE

wwwbrecouk





wwwbisgovuk



wwwdeccgovuk







wwwestorguk



English Heritage




wwwhsegovuk





Government)





Legislation











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

Index

A





B









C













Definition 31

D

DERSee Dwelling CO

2 Emission Rate





46ndash47

E



Energy performance


2 Emission Rate





F





GGlazing

See Windows

H




I





L




M



N



O


P








Regulations 1994 (SI 19943260)327


N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



INDEX L1B

R









S





T






U


Table 3


W




Area of glazing 42




N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

























N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs




15 Bonhill Street

London EC2P 2EA


Fax orders 020 7374 2737


Or order online at


RIBA Bookshops






ISBN 978 1 85946 325 3

Stock code 72233





wwwthenbscom

B ui l d i n g

R e g ul at i o

n s 2 0 1 0

A P P R OV E D

D O C UME NT L 1 B

C o


er

N L I N E V E R I N

8112019 Part L_Regs



L1B







N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





thermal elements






























E R I N

N L I N E V E R I N

8112019 Part L_Regs



23




thermal elements





























V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

BRE

wwwbrecouk





wwwbisgovuk



wwwdeccgovuk







wwwestorguk



English Heritage




wwwhsegovuk





Government)





Legislation











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

Index

A





B









C













Definition 31

D

DERSee Dwelling CO

2 Emission Rate





46ndash47

E



Energy performance


2 Emission Rate





F





GGlazing

See Windows

H




I





L




M



N



O


P








Regulations 1994 (SI 19943260)327


N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



INDEX L1B

R









S





T






U


Table 3


W




Area of glazing 42




N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

























N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs




15 Bonhill Street

London EC2P 2EA


Fax orders 020 7374 2737


Or order online at


RIBA Bookshops






ISBN 978 1 85946 325 3

Stock code 72233





wwwthenbscom

B ui l d i n g

R e g ul at i o

n s 2 0 1 0

A P P R OV E D

D O C UME NT L 1 B

C o


er

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs





thermal elements






























E R I N

N L I N E V E R I N

8112019 Part L_Regs



23




thermal elements





























V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

BRE

wwwbrecouk





wwwbisgovuk



wwwdeccgovuk







wwwestorguk



English Heritage




wwwhsegovuk





Government)





Legislation











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

Index

A





B









C













Definition 31

D

DERSee Dwelling CO

2 Emission Rate





46ndash47

E



Energy performance


2 Emission Rate





F





GGlazing

See Windows

H




I





L




M



N



O


P








Regulations 1994 (SI 19943260)327


N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



INDEX L1B

R









S





T






U


Table 3


W




Area of glazing 42




N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

























N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs




15 Bonhill Street

London EC2P 2EA


Fax orders 020 7374 2737


Or order online at


RIBA Bookshops






ISBN 978 1 85946 325 3

Stock code 72233





wwwthenbscom

B ui l d i n g

R e g ul at i o

n s 2 0 1 0

A P P R OV E D

D O C UME NT L 1 B

C o


er

N L I N E V E R I N

8112019 Part L_Regs





thermal elements






























E R I N

N L I N E V E R I N

8112019 Part L_Regs



23




thermal elements





























V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

BRE

wwwbrecouk





wwwbisgovuk



wwwdeccgovuk







wwwestorguk



English Heritage




wwwhsegovuk





Government)





Legislation











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

Index

A





B









C













Definition 31

D

DERSee Dwelling CO

2 Emission Rate





46ndash47

E



Energy performance


2 Emission Rate





F





GGlazing

See Windows

H




I





L




M



N



O


P








Regulations 1994 (SI 19943260)327


N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



INDEX L1B

R









S





T






U


Table 3


W




Area of glazing 42




N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

























N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs




15 Bonhill Street

London EC2P 2EA


Fax orders 020 7374 2737


Or order online at


RIBA Bookshops






ISBN 978 1 85946 325 3

Stock code 72233





wwwthenbscom

B ui l d i n g

R e g ul at i o

n s 2 0 1 0

A P P R OV E D

D O C UME NT L 1 B

C o


er

N L I N E V E R I N

8112019 Part L_Regs



23




thermal elements





























V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

BRE

wwwbrecouk





wwwbisgovuk



wwwdeccgovuk







wwwestorguk



English Heritage




wwwhsegovuk





Government)





Legislation











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

Index

A





B









C













Definition 31

D

DERSee Dwelling CO

2 Emission Rate





46ndash47

E



Energy performance


2 Emission Rate





F





GGlazing

See Windows

H




I





L




M



N



O


P








Regulations 1994 (SI 19943260)327


N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



INDEX L1B

R









S





T






U


Table 3


W




Area of glazing 42




N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

























N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs




15 Bonhill Street

London EC2P 2EA


Fax orders 020 7374 2737


Or order online at


RIBA Bookshops






ISBN 978 1 85946 325 3

Stock code 72233





wwwthenbscom

B ui l d i n g

R e g ul at i o

n s 2 0 1 0

A P P R OV E D

D O C UME NT L 1 B

C o


er

N L I N E V E R I N

8112019 Part L_Regs



L1B

BRE

wwwbrecouk





wwwbisgovuk



wwwdeccgovuk







wwwestorguk



English Heritage




wwwhsegovuk





Government)





Legislation











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

Index

A





B









C













Definition 31

D

DERSee Dwelling CO

2 Emission Rate





46ndash47

E



Energy performance


2 Emission Rate





F





GGlazing

See Windows

H




I





L




M



N



O


P








Regulations 1994 (SI 19943260)327


N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



INDEX L1B

R









S





T






U


Table 3


W




Area of glazing 42




N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

























N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs




15 Bonhill Street

London EC2P 2EA


Fax orders 020 7374 2737


Or order online at


RIBA Bookshops






ISBN 978 1 85946 325 3

Stock code 72233





wwwthenbscom

B ui l d i n g

R e g ul at i o

n s 2 0 1 0

A P P R OV E D

D O C UME NT L 1 B

C o


er

N L I N E V E R I N

8112019 Part L_Regs



L1B











N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



L1B

Index

A





B









C













Definition 31

D

DERSee Dwelling CO

2 Emission Rate





46ndash47

E



Energy performance


2 Emission Rate





F





GGlazing

See Windows

H




I





L




M



N



O


P








Regulations 1994 (SI 19943260)327


N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



INDEX L1B

R









S





T






U


Table 3


W




Area of glazing 42




N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

























N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs




15 Bonhill Street

London EC2P 2EA


Fax orders 020 7374 2737


Or order online at


RIBA Bookshops






ISBN 978 1 85946 325 3

Stock code 72233





wwwthenbscom

B ui l d i n g

R e g ul at i o

n s 2 0 1 0

A P P R OV E D

D O C UME NT L 1 B

C o


er

N L I N E V E R I N

8112019 Part L_Regs



L1B

Index

A





B









C













Definition 31

D

DERSee Dwelling CO

2 Emission Rate





46ndash47

E



Energy performance


2 Emission Rate





F





GGlazing

See Windows

H




I





L




M



N



O


P








Regulations 1994 (SI 19943260)327


N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs



INDEX L1B

R









S





T






U


Table 3


W




Area of glazing 42




N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

























N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs




15 Bonhill Street

London EC2P 2EA


Fax orders 020 7374 2737


Or order online at


RIBA Bookshops






ISBN 978 1 85946 325 3

Stock code 72233





wwwthenbscom

B ui l d i n g

R e g ul at i o

n s 2 0 1 0

A P P R OV E D

D O C UME NT L 1 B

C o


er

N L I N E V E R I N

8112019 Part L_Regs



INDEX L1B

R









S





T






U


Table 3


W




Area of glazing 42




N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs

























N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs




15 Bonhill Street

London EC2P 2EA


Fax orders 020 7374 2737


Or order online at


RIBA Bookshops






ISBN 978 1 85946 325 3

Stock code 72233





wwwthenbscom

B ui l d i n g

R e g ul at i o

n s 2 0 1 0

A P P R OV E D

D O C UME NT L 1 B

C o


er

N L I N E V E R I N

8112019 Part L_Regs

























N L I N E V E R I N

N L I N E V E R I N

8112019 Part L_Regs




15 Bonhill Street

London EC2P 2EA


Fax orders 020 7374 2737


Or order online at


RIBA Bookshops






ISBN 978 1 85946 325 3

Stock code 72233





wwwthenbscom

B ui l d i n g

R e g ul at i o

n s 2 0 1 0

A P P R OV E D

D O C UME NT L 1 B

C o


er

N L I N E V E R I N

8112019 Part L_Regs




15 Bonhill Street

London EC2P 2EA


Fax orders 020 7374 2737


Or order online at


RIBA Bookshops






ISBN 978 1 85946 325 3

Stock code 72233





wwwthenbscom

B ui l d i n g

R e g ul at i o

n s 2 0 1 0

A P P R OV E D

D O C UME NT L 1 B

C o


er

N L I N E V E R I N