Transforming homes from G to A - the University of · PDF fileTransforming homes from G to A...

Lo

wC

ar

bo

nH

ou

sin

gR

etr

ofit

1

Transforminghomes fromG toA

An assessment of the archetyperequirements and recommendations for

improving the energy efficiency ofdwellings in Greater Manchester

Low Carbon Housing RetrofitGreater Manchester

131263_City-South_Manchester_v5__ 19/03/2012 12:00

Lo

wC

ar

bo

nH

ou

sin

gR

etr

ofi

t

2

Foreword

Acknowledgements

Over the past few years there has been a growing recognition of the magnitude of the challenge that theUK and the rest of the world is facing in terms of meeting carbon emissions reduction targets.

Emissions related to domestic housing account for over

25% of our overall output and so housing has a critical

role to play in contributing to the wider goals.

As new technologies emerge for energy reduction and

generation it is easy to forget about the requirements to

properly insulate the fabric of existing buildings – this

document looks at the nature of Greater Manchester’s

housing stock and sets out approaches to move homes

towards the upper end of the energy efficiency scale.

Greater Manchester features many stakeholders fully

committed to the housing retrofit agenda – this document

will assist as initiatives such as Green Deal and the new

Energy Company Obligations are implemented and help

GM along the way towards its ambitious 2050 emission

reduction goals for housing.

Ashley Crumbley

Tom Rock, (Chair) City South Manchester Housing TrustAlan Foster, Homes and Communities Agency (HCA)Andy Kippax, Stockport Metropolitan Borough CouncilAndy Morris, Bolton at HomeCharlie Baker, UrbedGavin Summerson, Building Research EstablishmentMichael O’Doherty, Manchester City CouncilPaul Maidment, Northwards HousingRichard Hartless, Building Research EstablishmentRoss Hall, Building Research EstablishmentShona Thomas, Greater Manchester Low Carbon Housing Retrofit ProgrammeStephen Passmore, Energy Saving TrustStephen Todd, Salford UniversitySteve Parlby, Irwell Valley Housing AssociationTim Barwood, Greater Manchester Low Carbon Housing Retrofit ProgrammeTony Baldwinson, NW Centre for Construction InnovationWilliam Swan, Salford University


Lo

wC

ar

bo

nH

ou

sin

gR

etr

ofit

3

ContentsExecutive Summary and Recommendations

1 Developing a Housing Retrofit Standardfor Existing Stock• Background• The Challenge of the Task Group• Green Deal Guidance• Potential Financial Savings• Aims of the Report• Decision Making• Potential Economic and Social Benefits• Fuel Poverty• Energy Performance Certificate• Summary

2 Housing Retrofit potential in Greater Manchester• Property Archetypes• Identification of Property Types• Options for Improvement• Retrofit Potential• Measures Options –

Basic Measures –Intermediate measures –Major Measures

• Wall Types and Appropriate Treatment• Summary

3 Specific Considerations• Building Regulations and Planning• Flood Damage Risk• Fire Risk• Interstitial and Surface Condensation• Ventilation and Building Physics• Sustainability and the Home• Design Considerations• Technology Advancement• Summary

4 Conclusions

5 Recommendations

Technical Appendices:A: Typical Ranges of MeasuresB: Wall U-Values and ImprovementsC: References and SourcesD: Glossary of technical terms

Imag

eco

urte

syof

Man

ches

terC

ityCo

unci

l


Lo

wC

ar

bo

nH

ou

sin

gR

etr

ofi

t

4

Executive Summary and RecommendationsIntroduction

As we move closer to the Government’s launch of the Green Deal in autumn 2012, it is important for the Associationof Greater Manchester Authorities (AGMA) to ensure they are in a position to deliver the best advice and maximisethe benefits to its residents. Over the past 12 months Greater Manchester’s Low Carbon Economic Area (LCEA)Domestic Retrofit programmes have been focused on this agenda to ensure the region can maximise what theGreen Deal has to offer to GM residents.

In order to achieve this key housing retrofitstakeholders, operating through AGMA’sEnvironment Commission, have startedbringing together a set of independentrecommendations and technical advice thatis relevant to GM’s housing stockcharacteristics, which will help to underpinthe specifying and planning of retrofitprojects. In order to maximise the impact ofGreen Deal uptake and provide a route tomeeting the local and national emissionsreduction challenge for GM, this GreaterManchester Housing Retrofit DesignGuidance has been developed.

Aims of the report

There are more that 1.1 million homes inGreater Manchester which contribute 36% ofthe CO2 emissions for the area1. Thisprovides a significant challenge andopportunity to target domestic housing inorder to meet the local and nationalemissions reduction targets.

It is intended that this report will enable allusers, from individual householders to largescale landlords and those involved inplanning and installing retrofit measures, tounderstand the potential range of energyefficiency measures that may be fitted totheir properties and the most efficient orderin which to install them. In addition toapplying the basic, intermediate and majormeasures, the users’ opportunity for savingmoney by reducing their ongoing energyusage is highlighted. Theserecommendations and packages ofmeasures are linked to the GreaterManchester Climate Change Strategy2

emissions reduction target of 48% by 2020,and the national targets of 34% by 2020 and80% by 2050.

The principle aim is to maximise theinstallation of domestic retrofit measures bymaximising the take up of new and futurefunding mechanisms such as the Green

Deal, Energy Suppliers Obligation (ECO) andthe local ‘Get me Toasty’ insulation schemeand to ensure that such investment producesboth employment opportunities for itsresidents and starts to address theincreasing issue of those in, or moving into,fuel poverty.

The Retrofit Strategy endorses the ‘FabricFirst’ model for this programme.

1GM Low Carbon Housing Retrofit Strategy – discussion draft2Greater Manchester Climate Change Strategy: http://www.agma.gov.uk/cms_media/files/gm_climate_change_strategy_final1.pdf


Lo

wC

ar

bo

nH

ou

sin

gR

etr

ofit

5

3

2

1

1. Investment should first be made to reduce energy use - by improvingthe building fabric of homes (e.g. insulation glazing and air tightness)and their fit-out (e.g. lights. appliances and sanitary ware)

2 Occupiers should be engaged to promote greater ‘carbon literacy’.This should form a part of all activities, and should be supported ineach home by investment in energy monitoring devices and simplemeasures such as master switches.

3 Then investment can be made in reviewable energy technologies tosupply the remaining energy needs (e.g. solar photovoltaics, biomassboilers).

Fabric first!The GM energy hierarchy approach

Diagram from GM Retrofit Strategy draft

The scope of this report is limited to therange of actions appropriate for the physicalstructure of the dwelling, which are seen asthe critical first stage for the GM energyhierarchy as show in this diagram.Behavioural Change, Health/Fuel Poverty, andSkills/Training are addressed in other workgroups as part of the overall Housing Retrofitprogramme.

The wide ranging research and standardsreview carried out for this report has led tothe following conclusions andrecommendations. These will enable aCommon Standard and Framework of retrofitmeasures to be adopted across all areas andorganisations in Greater Manchester, yieldingsubstantial financial savings and a providinga pathway for achieving the local and

national carbon emissions targets in thedomestic housing retrofit sector.

Imag

eby

kind

perm

issi

onof

Ener

gySa

ving

Trus

t


Lo

wC

ar

bo

nH

ou

sin

gR

etr

ofi

t

6

The report concludes that

1 With 1.1 million homes which areproducing more than a third of the CO2

emissions in Greater Manchester, thedeveloping Green Deal represents asignificant opportunity for householdersand landlords to improve the energyefficiency of their properties. This willcontribute significantly towards therecently adopted Greater ManchesterClimate Change Strategy target of 48%carbon emissions reduction by 2020,which exceeds the national target of 34%.

2 A review of the housing stock hasidentified nine major archetypes ofproperties to aid understanding of whatis required.

3 A potential improvement required for eacharchetype to reach the national carbonemissions reduction targets of 34% by2020 and 80% by 2050, has beenidentified in the form of a SAP ratinglinked to an Energy PerformanceCertificate and the associated carbonemissions per meter squared for thatproperty type.

4 Each of these SAP target standards havethen been analysed and a suite of energyefficiency measures designed appropriateto each archetype, identified as basic,intermediate (2020 target) and majorinterventions (2050 target).

5 A full evaluation of the cost and energyrating of each measure is provided in thetechnical appendices.

6 Crucially information is also includedindicating the most efficient and costeffective order in which to install thesemeasures using natural trigger pointswithin the lifespan of the property and it’sownership. Examples of these triggerpoints would include such works as a newroof, new windows, kitchen/bathroomupgrades or an extension. Lifestylechanges are also recognised asappropriate trigger points, includingmoving home, increased or reducedfamily size or occupancy.

7 It is recognised that property owners areunlikely to undertake a full retrofit of theproperty all at once; this document willhelp to ensure that an incremental ‘wholehouse’ approach is as efficient and costeffective as possible.

8 The levels of SAP/EPC/kg CO2 targetsgive property owners the option toupgrade the energy efficiency to thehighest level possible during plannedwork to avoid potential wasteful andcostly revisiting of the same areas later onwhen the higher levels are likely to berequired.

9 A range of specific buildingconsiderations are discussed to ensureusers of this document are informed ofkey issues that are important in anyretrofit planning.

10 It is made clear that in order to reachthese very stretching national targets for2050 all the properties which alreadyexist in Greater Manchester will requiresome form of additional retrofit to ensurethey meet the energy efficiency standardsrequired to achieve the 80% emissionssavings.

11 Development of a Greater Manchesterweb portal and database of thesearchetypes and retrofit solutions couldeffectively be linked to the BuildingResearch Establishment (BRE) NationalRefurbishment Centre3 and the NationalEnergy Efficiency Data-Framework(NEED)4.

12 Finally it is also acknowledged that someof the SAP/EPC/kg CO2 targetsrecommended will have to take advantageof newly developing technologies thatmay not be fully available yet in order tobe cost effective.

3www.rethinkingrefurbishment.com4http://www.decc.gov.uk/assets/decc/11/stats/energy/energy-efficiency/2078-need-data-framework-report.pdf


Lo

wC

ar

bo

nH

ou

sin

gR

etr

ofit

7

Recommendations

Recommendations for this report were developed following the compilation of evidence by the GM Housing RetrofitStandards Group and the associated stakeholder seminar held in July 2010. The recommendations should beadopted to maximise the potential benefits of physical housing retrofit programmes and to endorse long termenergy efficiency changes in behaviour.

The following recommendations are made to inform those responsible for developing strategy and implementing domestic retrofit programmesin both the private and social sector.

Sector Recommendation

SocialLandlords

• That Social Landlords should take into consideration the recommended SAP/EPC/kg CO2 standards when developing,tendering or managing retrofit schemes.

• That they should also take these standards into consideration when preparing future asset plans and maintenancebudgets.

• To link these standards and targets to planned maintenance ‘trigger points’ such as kitchen/bathroom upgrades or newwindows/roofs etc, to ensure effective long term cost efficiencies.

• Take into consideration the items included in the specific considerations section when planning or tendering a project.

LocalAuthorities

• Local Authorities to recommend these SAP/EPC/kg CO2 standards to all social landlords, retrofit developers and privatehouseholders through the Planning and Building Control services.

• To work with private landlords and Landlords Associations to promote the installation of measures to improve the energyefficiency for the private rented stock. This will include promotion through the landlords forums, the Greater ManchesterLandlords Accreditation Scheme and where appropriate, active enforcement under the provision of the Housing Act 2004.

• That householders be proactively made aware of these standards and opportunities for funding linked to the GreenDeal/FITs/RHI etc when contact is made with the sustainability/housing or affordable warmth departments.

RetrofitDevelopers

• That developers, builders and designers include these standards in any retrofit schemes undertaken in GreaterManchester.

• That the higher level standards are recommended to ensure effective long term cost efficiencies for the owners.• Be aware of the potential for linking Green Deal and other local and national funding to these standards.• Take into consideration the items included in the specific considerations section when planning or tendering a project.

SchemeManagers

• To ensure that these standards are embedded in the project management and work plans.• To be aware of the potential for reaching the higher standards when retrofitting at a natural ‘trigger point’, rather than

costly revisiting at a later date.

Homeowners • To use this document to help plan the most efficient and effective energy efficient retrofit programme for their home,to ensure an incremental ‘whole house’ approach is used where possible.

• That these standards are included in the contract documentation for any scheme or project.• Take into consideration the items included in the specific considerations section when planning or contracting a project.

Large scaleSchemeDevelopers/Installers

• The Greater Manchester wide Get me Toasty scheme should take flood risk factors into account prior to recommendingspecific materials for CWI.

• Low Carbon Housing Retrofit/LCEA committee.

Low CarbonHousingRetrofit/LCEAboard

• To carry out an annual review of this report in light of developments in retrofit technology and funding models such asthe Green Deal. This will ensure that this document remains relevant and provides appropriate recommended standardsup to 2020.

• To monitor the developments in domestic energy efficiency and retrofit technologies and encourage trial pilot schemeswhere appropriate.

• To create the photo library of front elevations and develop the Greater Manchester Retrofit Housing Web Portal andDatabase to allow users to access the archetypes and measures packages as well as measuring progress towards theemissions reduction targets.


Lo

wC

ar

bo

nH

ou

sin

gR

etr

ofi

t

8

1. Developing a Retrofit Standard for ExistingHousing Stock in Greater ManchesterBackground: the Greater Manchester context.

A coordinated approach to improving existing housing stock is being developed and Greater Manchester’s LowCarbon Economic Area (LCEA) designation presents an opportunity to introduce a common standards frameworkfor all domestic retrofit works throughout the conurbation.

This report has been prepared by the LCEAHousing Retrofit Standards Group, whichreports to the Low Carbon Housing RetrofitSub-Group of the LCEA Board and to theAssociation of Greater ManchesterAuthorities’ (AGMA) EnvironmentCommission. Understanding the localhousing stock will play a vital part in thesuccess of the forthcoming basic energyefficiency measures programme, ‘Get meToasty’, which seeks to treat 75%(approximately 400,000) of under-insulatedlofts or un-insulated cavities by 2013 inGreater Manchester. This work provides avaluable opportunity to identify the totalretrofit potential for the range of existingdomestic properties, many of which werebuilt before the new building regulationscame into force, it will also ensure that themeasures that are installed achieve their fullenergy saving potential. It will also be crucialwhen work is being planned thathouseholders are given the opportunity tounderstand how to benefit from specifyingand installing higher standards of insulationand energy efficient technologies, and at thesame time being encouraged to thinkdifferently about their energy use to reducedemand.

However, the longer-term ambition is toengage with the whole of the existinghousing stock in order to reach the veryambitious national carbon emission reductiontargets for 2020 and 2050. There are a totalof 1.1 million homes in Greater Manchester,the majority (38%) of which consist of semi-detached properties, followed by terraced(33%), flats or maisonettes (15%) anddetached (14%) properties. Within this stock

it is estimated that 25% of the stock is ofsolid wall construction and that there are stillover 500,000 untreated lofts and cavity wallsacross Greater Manchester5. The RetrofitStrategy proposes a GM wide network oflocal showhomes and streets in everyneighbourhood, where the notion of ‘seeingis believing’ will inspire take up of the GreenDeal.

Loft Insulation

Fit loft insulation and savearound £110 and around

1 tonne of CO2 pa

Hot water tank

Fit an insulating jacketaround the hot water tankand save £20 and 160kg

of CO2 pa

Shower

Have a shower insteadof a bath and use

nearly two thirds lesswater and energy

Boiler

Upgrade to a condensingboiler and save a third on

your heating bills andaround 875kg of CO2 pa

ESR fridge freezer

Upgrading to an EnergySaving Recommended

one can save up to £37and 150kg of CO2 pa

Washing

Wash clothes at 30˚C rather thanat higher temperatures and use

a third less electricity, and soproduces a third less CO2

Energy saving lightbulb

One energy saving lightbulbwill save £7 and around 45kg

of CO2 pa

Cavity wall insulation

Insulate cavity walls and savearound £90 and around

750kg of CO2 pa

Draught proofing

Draught proof windows anddoors and save £20 andaround 155kg of CO2 pa

Appliances

Turn TVs and otherappliances off

standby when notin use

Fill gaps in floors

Fill in gaps in floors andskirting and save around£15 and around 130kg

of CO2 pa

Thermostat

Turn down thethermostat by 1˚C andsave nearly £40 and

around 325kg of CO2 pa

26% Loft26% of heat lost from an uninsulated home isthrough the roof. Fitting sufficient loft insulationis one of the easiest and most cost effective waysof saving energy and money.

18%

WindowsNearly a fifth of heat lost from anuninsulated home can be throughwindows. Double glazing can savearound £90 and 700kg CO2 pa.

33%WallsWalls leak more heat than any other partof the home – around a third in anuninsulated home. If your home has cavitywalls, insulating them is the best way youcan save energy and money.

11%Doors and FloorsGaps around doors and floors account foraround 11% of heat loss in an uninsulatedhome. Sealing up gaps will stop heatescaping.

Energy Saving RecommendedFor the most energy efficient products, always look for theEnergy Saving Recommended logo. KEY

Grants and adviceavailable throughEnergy Saving Trust

No-costor low-costmeasures

For more independent and impartial advice on energy saving in the homecall 0800 512 012 or visit www.energysavingtrust.org.uk© Energy Saving Trust 2007. E&OE

How energy efficientis your home?

5Retrofit Strategy 2011 and Energy Saving Trust’sHEED database 2010


Lo

wC

ar

bo

nH

ou

sin

gR

etr

ofit

9

The Challenge for the RetrofitStandards Group

In July 2010 a stakeholder engagementseminar was held to assess the need for aGreater Manchester Retrofit Standard inresponse to local and national developments.From this the LCEA Retrofit Standards Groupwas formed and tasked with thedevelopment of this standard, through theidentification of property types, measuresand the options for the potentialimprovement in energy performance of adwelling. The range of measures identifiedhas been developed to apply across themajority of property archetypes.

The Group’s initial starting point has been toidentify the most common housing typesfound within Greater Manchester. Then toapply an archetype grouping across threebands, against which the properties can becategorised. Against each archetype a briefdescription of the original construction detailsthat are common to the age and materialsused for that period has been given. It isrecognised that subsequent individualimprovements may have been carried outeither through planned investment or byindividual homeowners. Therefore, it will benecessary for all users to have their dwellinginitially surveyed and assessed to establishthe actual energy rating. The archetype listand measures set out in this report will assistthe user to decide where their propertycurrently falls with regard to therecommended measures described withinthese retrofit proposals.

Many other factors such as location,conservation status, occupation etc willaffect the identified measuresrecommended. These factors are discussedin the GM Retrofit Strategy and the GMGreen Deal Intelligence report which will bepublished in the near future.

The initial physical upgrade of a property toimprove energy performance will providesignificantly enhanced thermal and financialbenefits when combined with the behaviouralchanges described in another key LowCarbon Housing Retrofit report ‘The MissingQuarter’6.

It is crucial that all retrofit schemes acrossGreater Manchester are complemented byawareness and behaviour changeprogrammes to ensure that occupants of theimproved properties understand and take fulladvantage of the upgrades made to theirhomes.

Green Deal Guidance

The Government’s Green Deal scheme aimsto enable households to install home energymeasures that are in part funded by a loanattached to the property rather than thehousehold and repaid from savings in energybills. The scheme has been driven by theneed for a national comprehensive retrofitprogramme and carbon emission targets setfor 2020 and 2050. In addition to its coreaims, the Green Deal provides the potentialto unlock not only a huge economicopportunity, but social benefits throughwarmer homes and mitigation of rising fuel

costs, it also raises the prospect of localaction where residents act together to bringabout improvements to their homes andcommunities.

In 2011, Greater Manchester was chosen byGovernment to trail-blaze a pilot for theGreen Deal scheme within social housingahead of its nationwide launch. GM has asocial housing stock of over 260,000properties and of these up to 25,000 fall inthe ‘hard to treat’ category. The trailblazerwill seek to establish delivery partnershipsand supply chains to build customerconfidence in the Green Deal. It will beessential that long term behaviour changesupport for householders is intrinsic to theGreen Deal approach in order to achieve thebest possible savings. The success of theGreen Deal relies on the application of the‘Golden Rule’ where customer repaymentsare always lower than the savings madethough the energy efficiency works. TheGolden Rule calculations will be based onassumptions and modelling. In its practicalapplication it is critical that households adoptbehaviour that will maximise the benefits ofthe physical measure to ensure that theanticipated savings are made.

6Missing Quarter report: http://manchesterismyplanet.com/behavioural-change

Imag

eby

kind

perm

issi

onof

Ener

gySa

ving

Trus

t


Lo

wC

ar

bo

nH

ou

sin

gR

etr

ofi

t

10

Under the current proposals for Green Dealthe Government has set certain criteria whichmust be met in order for the finance to bemade available, which protects the residentfrom committing themselves to undertakinguneconomic measures within their homes.These criteria are subject to confirmation bythe end of 2011. Further information will alsobe made available regarding the role ofsocial housing providers and the criteria forsocial housing tenants in relation to theGreen Deal.

A full discussion of the Green Dealrequirements and data intelligence isincluded in the GM Green Deal Intelligencereport which will be published in the nearfuture.

Green Deal Criteria7:

The first is called the “Golden Rule”; it statesthat the measures recommended mustproduce sufficient savings on the annualenergy bill to pay back the initial cost ofcarrying out the works.

• The identified measures must be approvedso that the claimed bill savings can bethose accredited to pay back the loan.

• The provider of the loan must giveappropriate advice under the terms of theConsumer Credit Act, under which theindividual’s circumstances shall be takeninto account.

• The loan stays with the property not theindividual, so is paid back as part of thefuture energy bills.

• The present energy provider must beinformed of the proposed measures beforethe funds are released to undertake theworks.

• The measures recommended should beidentified by an accredited DomesticEnergy Assessor “DEA” who hasundertaken an Energy PerformanceCertificate on the property, or be based onthe recommendations contained within anexisting Energy Performance Certificatewhich has been lodged by a DEA.An objective adviser can be used, ifappropriate.

• The loan must be paid back before themeasures undertaken have reachedtheir replacement date, this can be up to25 years.

• Only accredited installers/contractors willbe allowed to undertake the recommendedmeasures, or installations, for the funds tobe released under the Green Deal offer.

• Any Green Deal provider must haveconsent from all relevant parties, includingthe express consent of the current energybill-payer.

• Properties should have the basic energyefficiency measures undertaken prior toimplementing the high tech solutions formaximising energy income.

• The presence of a Green Deal charge mustbe properly disclosed to all futureoccupants whether through selling oroffering the property for rent.

• There is a move at Government level tolook at how micro-generation income cansubsidise retrofit.

These measures have been put in place toprotect residents and will ensure that onlyworks appropriate to reducing the property’soverall energy demands will be approvedunder the Green Deal.

The GM Housing Retrofit strategy is beingdeveloped in advance of the launch of theGreen Deal will support this by identifying themost effective and appropriate combinationsof measures, assembled into packages, forthe different property types. The level ofretrofit activity is being monitored by pro-active information gathering across theregion regarding the property types and themeasures installed in them over time, whichin turn will enable the retrofit packages to beupdated and refined.

7Department of Energy and Climate Change: http://www.decc.gov.uk/Energy Saving Trust: http://www.energysavingtrust.org.uk/

Imag

eby

kind

perm

issi

onof

Ener

gySa

ving

Trus

t


Lo

wC

ar

bo

nH

ou

sin

gR

etr

ofit

11

Retrofit Finance models:

As well as the Green Deal a new EnergyCompany Obligation (ECO) fund is underdevelopment which will be a replacement tothe existing Carbon Emissions ReductionTarget (CERT) and Community Energy SavingProgramme (CESP) funds. A range of otherretrofit funding is available for renewabletechnologies such as the Feed in Tariff (FiT)and Renewable Heat Incentive (RHI). It is theintention that all appropriate retrofit fundingshould be maximised across GreaterManchester and that all schemes should beencouraged to meet the common standardand framework proposed in this report.

In addition to national funding programmes,Greater Manchester has developed the local‘Get me Toasty’ insulation scheme whichprovides free cavity wall and loft insulation tothe majority of private sector households,subject to survey. This programme aims toinstall 400,000 basic measures by 2013.

The above table sets out estimated potentialsavings for introducing these measureswithin the home (based on a 3 bed semidetached house). It should be noted thatsavings cannot be simply added togetherwhere multiple measures are being installed,because the savings from measures areinterdependent. Individuals should be mindfulthat the performance of the actual measuresas noted in the table above will be subject toa range of factors such as the size ofproperty, occupancy and individualpreference for heating their property.The savings shown have been developed

from work done by the Energy Saving Trust(EST) and Building Research Establishment(BRE) along with other material used withinthis report.

Further information on a wide range ofenergy efficiency work and advice isavailable through accessing their web sitesshown below:

www.energysavingtrust.gov.uk

www.bre.co.uk

8These figures are based on the Department for Energy and Climate Change (DECC), Building Research Establishment (BRE) and the EnergySaving Trust’s (EST) advice. All the savings figures are based on a 3 bedroom semi detached property.:(http://www.energysavingtrust.org.uk/business/Business/Information/Energy-Saving-Statistics/Energy-Saving-Assumptions)9These payback periods are based on 2010 fuel prices and are likely to become shorter as fuel prices increase

Imag

eco

urte

syof

Crea

tive

Conc

ern

Potential financial savings from retrofit installed measures

Residents can achieve substantial savings on their annual energy bills byinstalling a range of measures, some of which are shown below:

Indicative Measures (figures for 2010) Approx savings(£/year)8

Payback time(years)9

Cavity wall insulation 110 2

Full Loft insulation 150 1

Loft insulation top-up 45 6

New “A” rated Condensing Boiler 225 8 – 11

Voltage optimisation 35 13

Internal solid wall insulation 365 15 – 23

External solid wall insulation 385 27 – 38

Solar Panels (water) 75 33 – 46

Ground Source Heat Pumps 125 36 – 48

Photovoltaic PV (electric) 92 41 – 60

Double Glazed PVCu Windows 85 41 – 53

Heat Recovery from Air (MVHR) 75 46 – 60

PVCu insulated Doors 15 50 – 57


Lo

wC

ar

bo

nH

ou

sin

gR

etr

ofi

t

12

Aims of the report

It is intended that this report will enable allusers, from individual householders to largescale landlords and those involved inplanning and installing retrofit measures, tounderstand the potential range of energyefficiency measures that may be fitted totheir properties and the most efficient orderin which to install them. In addition toapplying the basic and intermediatemeasures the user’s opportunity for savingmoney by reducing their ongoing energyusage is highlighted. Theserecommendations and packages ofmeasures are linked to the local 2020Greater Manchester Climate Change Strategyemissions saving target of 48%, and thenational targets of 34% by 2020 and 80%by 2050.

This work has been undertaken through theLow Carbon Economic Area DomesticRetrofit programme in order to offerrecommendations and advice on thepotential of energy efficiency measures thatcan benefit all the properties within theGreater Manchester area. The mainarchetypes and their recommendedmeasures are described in this report toassist users in identifying the presentcondition and likely energy efficiency of theirproperties and the potential improvements

and savings which can be achieved byinvesting in the recommended measures.

The principle objective is to provide clearrealistic targets for typical property typeswithin Greater Manchester and a range ofclear, simple and increasingly cost effectiveretrofit package options for our residents,landlords, developers and installers, bybringing together a range of services that willensure they receive the best advice andsupport.

Creating these local archetype standards andretrofit package options for 2020 and 2050will meet the challenges set out in the LCEALow Carbon Housing Retrofit Strategy.

It is anticipated that Greater Manchester willprovide a lead both locally and nationally indriving down the levels of domesticemissions in line with or ahead of thenational timescales.

Decision Making

As well as the physical retrofittinginformation in this report a range of furthersupport and advice is available from thewider AGMA domestic retrofit programmework being undertaken. It is intended thatusers will be able to access the following:

• Guidance on how to best ensure thatbehavioural change programmes areeffective and properly integrated intoretrofit projects as described in the‘Missing Quarter’ report.

• Obtain objective advice on retrofitstandards and appropriate measures to beundertaken as described in this report andin the Retrofit Strategy.

• Support through Greater Manchester’sapproach to Green Deal:

• AGMA is working towards creating themost appropriate delivery programmefor Green Deal for the conurbationthrough the establishment of a GreaterManchester Green Dealpartnership/framework designed to giveconfidence to consumers and strategicdirection to activity. This approach willprovide access to:

• An independent, impartial and expertcustomer advice service that cansupport the customer journey andpromote most appropriate retrofitproject approaches.

• Accredited suppliers whose materialsand performance meets the requiredspecifications and standards.

• Accredited installers/contractorswhose operatives are appropriatelytrained to undertake these works andinstallations within the home.

• The best market prices forguaranteeing both materials andworkmanship.

• Installers/contractors who can ifneeded provide servicing andmaintenance support, if called upon.

• Guarantees that will be honoured byboth suppliers and installers.

Imag

efro

m‘T

heM

issi

ngQu

arte

r’


Lo

wC

ar

bo

nH

ou

sin

gR

etr

ofit

13

It is expected that residents, landlords andowners who wish to consider the Green Dealoffer for their property will find this suite ofadvice and guidance helpful. It is furtherhoped that the user will decide to use TheGreater Manchester Green Deal Partnershipnetwork of selected independent andobjective advisors to support accessing theGreen Deal and other funding options,administration of the works and procurementof the recommended retrofit measures.

Potential Low Carbon Economicand Social Benefits

Our aim is to put every representative hometype in the area on a database accessiblethrough a web portal, so it can be assessedagainst this GM Housing Retrofit Standard, tohighlight the most cost and energy efficiencyinterventions based on property type andother stock intelligence. This database willalso allow forward planning of any retrofittingwork so that when homes change handsfuture householders or managers will be ableto pick up where the previous ones left off.

A core ‘grid’ of 9 principle types of propertiesand approximately 24 types of interventionshave been identified and developed intoretrofit option packages linked to the national2020 and 2050 emissions reduction targets.This will enable adoption of these standardpackages as a Greater Manchester coreprogramme of improvements to homes,providing the AGMA ‘family’ of organisationswith a common framework within which tomaximise a range of low carbon economicand social benefits including:

• Provision of business assistance toConstruction SMEs (small and mediumenterprises) located within the conurbationto maximise the capacity of local firms tobid for and undertake the works.

• Understanding of the range ofinterventions that will help make best useof local existing and potential sources ofConstruction Products. This will help tominimise the environmental impact duringthe manufacturing and transportingstages, and to maximise the localeconomic impact and its multiplier effects.

• The option packages will hopefully enablethe supply chain to develop with moreconfidence about the future and thecapacity needed.

• Greater Manchester’s wide sharing of bestpractice and intelligence on the regionalsupplier base will enable these packagesto be updated and remain relevant.

• Working with local colleges, and with areateams focussed on assisting NEET (not inemployment, education or training) youngpeople to provide additional incentives todevelop and join Construction Courses forsuccessful sandwich placements andimproved job prospects.

• Providing a focus on ‘entry level’construction work opportunities particularlyfor families with complex needs and withinter-generational unemployment, as asupported package with college andmentoring.

• Developing an understanding ofhouseholds in fuel poverty (see below) andusing this to inform the strand of theforthcoming Green Deal programme whichwill allow for the PAYS (pay as you save)principle to be subsidised by public funds.

• To place this framework of specificinterventions in the public domain, with thestability of commitment from across therange of Greater Manchesterorganisations, as a resource to otherprivate sector investors in the DomesticRefurbishment market, including ‘greenmortgage’ providers and other substantialfund holders and investors.

The opportunities to realise the economicpotential of the Green Deal in GreaterManchester are further discussed in the GMHousing Retrofit Strategy.

Fuel Poverty.

The existing Government’s definition of fuelpoverty is when a household spends 10% ormore of its income on fuel costs; however anew definition is under development. Fuelpoverty is an issue that disproportionatelyaffects households on low incomes and canseverely impact on the health and wellbeingof vulnerable households, and in particularthe elderly. Improving the energy efficiency ofproperties will assist greatly in minimisingthe health and financial impacts of fuelpoverty.

Certain national funding streams have beenavailable to target Fuel Poverty, with the newEnergy Company Obligation (ECO) due toreplace the existing Community EnergySaving Programme (CESP) next year.


Lo

wC

ar

bo

nH

ou

sin

gR

etr

ofi

t

14

Energy Performance Certificate10

The principle tool for assessing a dwelling’senergy efficiency performance is theStandard Assessment Procedure “SAP”which categorises the dwelling using sevenband ratings from “A”, the best performing,to “G”, the worst performing, and is normallydisplayed on an issued Energy PerformanceCertificate (EPC).

The title for this document is ‘Transforminghomes from G to A’ based on thisimprovement of energy efficiency SAP ratingwhich will be required from all domesticproperties to meet the GM national emissionsreduction targets. The Retrofit Strategyindicates that to achieve the nationalstandards for 2050 across GreaterManchester 90% of all homes will need toachieve an average of band B.

The EPC certificates also show a variety ofuseful information relating to a dwelling; fromits actual energy rating together with its

potential rating should the owner take actionand invest in the recommended measureslisted in the accompanying report.

An Energy Performance Certificate displayshowing the proposed improvements in SAPbanding is shown below.

If the dwelling has had an EPC assessmentundertaken to establish its SAP rating, as aninitial starting point for planning any retrofitworks the EPC certificate should be viewedto evaluate the current status and review thepotential measures recommended forimproving the energy efficiency.

At the time of writing this report theGovernment is currently looking atintroducing a new layout for the EPCcertificate, which will provide clearer adviceto the owner on what initiatives can beundertaken to enhance their propertiesoverall energy performance and the savingsthat would result.

Summary

The opportunity provided by both the localGM and national emissions reductionstargets and the development of fundingmechanisms such as the Green Deal, EnergyCompany Obligation, FITs and RHI and local‘Get me Toasty’ scheme has led to thedevelopment of a range of work packages forLow Carbon Housing Retrofitting. It is seen asimportant and economically astute toencourage all ten authorities and allorganisations in Greater Manchester to workto a common framework of targets,standards, methodologies and timeframes.

It is recognised that interventions throughworks only will not address the behaviouralchanges necessary to ensure that theoccupants achieve the full potential savingson their energy bills and that advice andsupport are therefore also key factors inreducing emissions. It is recommended thata Greater Manchester housing stockdatabase and web portal be developed tokeep track of improvement and to allowowners to search for their house type and themost effective measures packages.A

EF

G

BC

D

Current Potential

90%of stock

10%of stock

GMaverage

Diag

ram

from

GMRe

trofit

Stra

tegy

draf

tSou

rce:

DCLG

10http://www.direct.gov.uk/en/HomeAndCommunity/BuyingAndSellingYourHome/Energyperformancecertificates/index.htm

Proposed Greater ManchesterEPC Targets


Lo

wC

ar

bo

nH

ou

sin

gR

etr

ofit

15

The journey of improving solid walls with insulation

It’s not just about improving energy efficiency is it?

Before During After

Before During After


Lo

wC

ar

bo

nH

ou

sin

gR

etr

ofi

t

16

Archetype 3 pre 1919

Typical property: Large‘Victorian’/’Edwardian’ detached house,brick built with 225 mm or 340 mm walls.

Includes: All solid wall constructiondetached housing, including ‘finger cavity’stock brick walls, and larger 340 mm solidwalls. As a general rule, this would includeall detached property built before 1919.

2. Housing Retrofit potential inGreater Manchester.Property Archetypes

The initial approach taken by the Retrofit Standards Group has been to categorise the representative property typesthroughout the GM area into set archetypes groupings. The 9 most common GM property types have beenidentified. Archetypes 1 to 8 represent over 95% of the housing stock11, less common, non traditional property typeshave been put together in Archetype 9. This approach ensures that the original construction standards for eachtype are accounted for and appropriate to the retrofit package options being recommended.

Identification of Property Types

A library of photographs of typical front elevations is being collated to assist in identifying the dwellings classifications listed in the archetypes.This approach has enabled the Retrofit Standards Group to ensure it has included as many of the representative archetypes across the GMarea as possible. The aim is to establish a web portal where you will be able to view this library by accessing a Greater Manchester LowCarbon Economic Area website to help identify the correct house type category and package of retrofit options for your property.

A brief description of archetypes 1-9 is shown below and on page 17 for reference purposes:

Categorisation of Wall types Solid Wall(Generally all pre 1919 housing)

Cavity Wall(Generally all brick built post 1919)

All ‘non traditional’construction

Mid – terraced 1 5 9

Semi-detached/end terraced 2 6 9a

Detached 3 7 9b

All flats 4 8 9c


Typical property: ‘Victorian’ 2 storey pre1919 mid terraced house, brick built with225 mm walls and a slate roof.

Includes: All solid wall construction midterraced housing including ‘finger cavity’stock brick walls, and larger 340 mm solidwalls. As a general rule, this would includeall terraced property built before 1919.

Archetype 2 pre 1919Typical property: ‘Victorian’ 2 storey pre1919 ‘end of’ terraced house or smallsemi-detached, brick built with 225 mmwalls and a slate roof.

Includes: All solid wall construction end ofterrace/semi – detached housing, including‘finger cavity’ stock brick walls, and larger340 mm solid walls. As a general rule,this would include all semidetached/endterraced property built before 1919.

11http://data.gov.uk/dataset/english_house_condition_survey


Lo

wC

ar

bo

nH

ou

sin

gR

etr

ofit

17


Typical property: Converted Large‘Victorian’/’Edwardian’ house, brick builtwith 225 mm or 340 mm walls.

Includes: All flats in buildings of solid wallconstruction individually evaluated.


Typical property: 1960’s ‘town house’with 275 mm cavity walls.

Includes: All cavity wall properties,including properties with partial cladding,and tile hung bays. As a general rule, thiswould include all mid terraced propertiesbuilt from 1920 up to 2000.

Archetype 6 1937

Typical property: 1930’s ‘inter war’ semidetached house with 275 mm cavity walls.

Includes: All cavity wall properties,including properties with partial cladding,and tile hung bays. As a general rule, thiswould include all semi detached/endterraced properties built from 1920 up to2000.

Archetype 7 1930

Typical property: 1930’s ‘inter war’detached house with 275 mm cavity walls.

Includes: All cavity wall properties,including properties with partial cladding,and tile hung bays. As a general rule, thiswould include all detached properties builtfrom 1920 up to 2000.


Typical property: 1950’s ‘low rise’ brickbuilt flats, with 275 mm cavity walls.

Includes: All cavity wall properties,including properties with partial cladding,and tile hung bays. As a general rule, thiswould include all low rise brick built flatsconstructed from 1920 up to 2000.

Archetype 9, 9a, & 9b 1974

Typical property: 1960’s ‘non traditional’low rise construction.

Includes: All non traditional construction,including ‘system built’ properties such asWimpey ‘no-fines’ Reema hollow panel,high rise concrete frame flats, and timberframed housing.

Archetype 9c

Typical property: Medium and High riseflats


Lo

wC

ar

bo

nH

ou

sin

gR

etr

ofi

t

18

Options for Improvement through Identified Measures

For each property archetype three approaches have been identified depending on the extent and standard to which theproperties are to be improved, these are linked to the national emissions reduction requirements for 2020 and 2050.

The Standard options are:

• Basic Measures

• Intermediate Measures (2020 Standard)

• Major Measures (including newtechnology) (2050 Standard)

Basic and intermediate measures, as theirname implies will not be sufficient to meetthe national 2050 target meaning that theproperties will have to be retrofitted at leastonce more before then.

The table below shows the “as built” SAPrating and related EPC band for eacharchetype. It shows the level of improvementthat each requires to meet the 3 standards.

Type

*All figures use NHER StockAssessor calculations

As Built* SAP/EPCBand /kgCO2/m2

After Basic Measures*SAP/EPC Band/kgCO2/m2

After intermediateMeasures 2020*SAP/EPC Band/kgCO2/m2

After Major Measures2050* SAP/EPC Band/kgCO2/m2

Archetype 1<1900 mid/terraced house withsolid wall

SAP 1 band G CO2 1 SAP 57 band D CO2 46 SAP 66 band D CO2 61 SAP 87 band B CO2 84

Archetype 2<1900 end/terraced house withsolid wall

SAP 1 band G CO2 1 SAP 55 band D CO2 49 SAP 64 band D CO2 59 SAP 83 band B CO2 80

Archetype 3<1900 large detached housewith solid wall

SAP 1 band G CO2 1 SAP 52 band E CO2 46 SAP 66 band D CO2 61 SAP 80 band C CO2 76

Archetype 4Converted 1900-29 largedetached house with solid wall

SAP 1 band G CO2 1 SAP 56 band D CO2 50 SAP 78 band C CO2 76 SAP 87 band B CO2 85

Archetype 51960 mid terraced house withcavity walls including those withtile hung bays

SAP 48 band E CO2 43 SAP 64 band D CO2 60 SAP 72 band C CO2 70 SAP 88 band B CO2 86

Archetype 61930 Semi detached house withcavity walls including those withtile hung bays


Archetype 71930 detached house withcavity walls including those withtile hung bays


Archetype 81950 low rise cavity brick builtflats

SAP 69 band C CO2 66 SAP 71 band C CO2 67 SAP 77 band C CO2 73 SAP 94 band A CO2 92

Archetype 9, 9a, 9b, & 9c1960 system built mid/terracedwimpy no-fines etc

SAP 53 band E CO2 49 SAP 63 band D CO2 57 SAP 71 band C CO2 67 SAP 85 band B CO2 81


The NHER Assessor software used to developthese target standards is based on reducedSAP (RD SAP) which relies on approximationsand assumptions. Calculations carried outusing full SAP methodology may therefore bedifferent and are likely to be more accurate.

It is apparent from the above table thatespecially with the older stock; it may not bepossible to achieve the set standards by2020 without major investment being made.

Users will also need to consider when thisinvestment is to be made on a property andhow best it will contribute to the 2050targets. These aim to reduce the averagehome’s CO2 emissions from 6 tonnes downto only 1.5 tonnes per year, to meet theoverall 80% reduction targets set by theGovernment for 2050.

The three recommended Basic, Intermediateand Major Standards measures identifiedwhen implemented will impact onSAP/EPC/kg CO2 levels. They have beenbroken down into sub group elements to helpusers decide where their property is inrelation to the works being recommended.This will also help to identify whether theinvestment will be cost effective in the long-term and help to reduce the user’s potentialfuture energy costs.

Specifications for these retrofit packageoptions can be found in TechnicalAppendix A.

Retrofit potential propertyoverview

This sectional view of a property shows whatcan be done in order to enhance the energyefficiency of a property. Specific details forthese elements are listed within each of theBasic, Intermediate and Major retrofitoptions packages. It is important to realisethat not all the work is likely to be carriedout at one time, but will be bestundertaken when a natural ‘trigger point’ isreached eg when work is being carried outsuch as new kitchen/bathroom or roof orwhen family numbers change.

A Solar thermal or photovoltaic panels

B Full Loft insulation & Top up

C Internal heat recovery unit

D Low energy light bulbs

E Ventilation extractor fan

F Double or triple glazed windows

G Hardboard laid over floors & sealedskirting boards to prevent drafts

H External walls, see treatment potentialin the Technical Appendix

I Insulated door and frame fitted

J Voltage optimisation meter fitted toelectric distribution board

K Timber floor overlaid with hardboard &sealed skirting boards to stop drafts

L Insulation fitted externally to preventcold bridge

M Solid floor renewed with insulationlayer installed

N External garden used for groundsource heat recovery or alternativeuse air source heat recovery units

19

Lo

wC

ar

bo

nH

ou

sin

gR

etr

ofit

Diag

ram

cour

tesy

ofCi

tySo

uth

Man

ches

terH

ousi

ngTr

ust


Lo

wC

ar

bo

nH

ou

sin

gR

etr

ofi

t

20

Basic MeasuresThese works will improvethe energy efficiency ofthe properties and reduceenergy usage and theexpenditure on fuel billsand should be consideredas a minimum first stagefor retrofitting.

Although not part of the buildingfabric, installation of energyefficient ‘A’ rated appliancesshould also be an intrinsic partof any basic retrofit project.

Roofs

Pitched Roofs Pitched roofs insulated at ceiling level minimum 270mm. Target U-value max ~ 0.16W/m2K

Pitched roofs insulated at Rafter level Target U-value ~ 0.18W/m2K.

Flat Roofs Usually upgraded as part of a re-roofing project. Target U-value ~ 0.18W/m2K

Walls

Cavity Walls Cavity fill. Performance dependent on cavity width and materials.Target U-value ~ 0.58W/m2K

Draught proofing/Ventilation Provide basic sealing measures around windows and doors, walls, floors, roofs and aroundservice entry points and loft hatches maintaining background ventilation requirements.

Install extraction fans to the current Part F of the Building Regulations.

Heating Controls Central heating systems to be interlocked and controlled by a programmer with separatechannels for heating and hot water; a cylinder thermostat; TRVs.

Low Energy Lighting Install 100% low energy lighting

LoftInsulation

Reducedflow hotwaterfittings

Primarypipeworkinsulation

Thermostaticradiator valves Draught

proofing

Energysavinglightbulbs

Cavitywallinsulation

Reducedinfiltration

Diagram courtesy of EST


Lo

wC

ar

bo

nH

ou

sin

gR

etr

ofit

21

Intermediate Measureslinked to 34% 2020 national emissions targets and the 48% Greater Manchester target.

These measures fit into packages that will make the most sense together both to avoid repeat work but also ensure maximum energy andcost efficiency for each measure.

Roofs

Pitched Roofs Pitched roofs insulated at ceiling level. Target U-value ~ 0.1W/m2K.

Flat Roofs Usually upgraded as part of a re-roofing project. Target U-value ~0.12W/m2K

Walls

Solid External Walls Internal insulation. Performance dependent on system.Target U-value ~ 0.25W/m2K External insulation.Performance dependant on system. Target U-value ~ 0.2W/m2K

Cavity Walls Cavity fill and internal insulation. Performance dependent on cavitywidth and materials. Target U-value ~ 0.2W/m2K.Cavity fill and external insulation. Performance dependent on cavitywidth and materials. Target U-value ~ 0.16W/m2K

Windows and Doors New energy efficient windows and doors. Target U-values Windows~ 0.6-1.2W/m2K, Doors 0.8-1.2 W/m2K.

Ground and Exposed Floors Suspended timber (access and scope of works dependent)

Possible insulation between the joists and draught proof.Target U-value ~ 0.25W/m2K

Ground Supported Slabs – overlay insulation. Performancedependant on system. Target U-value ~ 0.25W/m2K

Perimeter Trench insulation. Performance dependant on system.Target U-value ~ 0.45W/m2K

Thermal Bridging Minimise the effects of thermal bridging by careful detailing.

Draught proofing/Ventilation Draught proof to a target of 5m3/hr at 50Pa. Install low energyextract fans

Heating Systems/Controls Upgrade gas boilers to “A” rated condensing incorporating a fluegas heat recovery unit and high efficiency hot water system.

Controls - as for Basic Measures and use of a weather and/or loadcompensator


Lo

wC

ar

bo

nH

ou

sin

gR

etr

ofi

t

22

Major Measures(Including newtechnology) – linkedto 80% 2050 nationalemissions targets.

While these measures canbe more expensive ordisruptive, the possibilitiesof revenue generation fromsome of these measureswill mean that in somecircumstance they shouldbe considered earlier.

Reduced/Sensor flowhot waterfittings

Air sourceheat pumps,(or groundsource heatpumps inlargerproperties)

Primarypipeworkinsulation

Thermostaticradiator valves Draught proofing

Energy savinglight bulbs

Loftinsulation


Ground and Exposed Floors Replace existing ground floor. Target U-value ~ 0.12W/m2K

Draught proofing/Ventilation Draught proof to a target of 3m3/hr at 50Pa.

Install whole house ventilation either using passive stack, or mechanical ventilation with heat recoveryminimum 85% efficient.

Renewables Install Solar Thermal system

Install PV System

Individual / communal biomass boiler/ heating Install a ground/air source heat pump

Community heating and combined heat and power

Install a micro CHP system (combined heat and power)

Install a waste water/heat recovery system

TripleGlazing

Reducedinfiltration

Cavity wallinsulation

HighperformanceinsulatedDHW cylinder

SolarPhotovoltaic

Solar waterheating

External wallinsulation

The Technical appendices include additional information and recommendations on the range of measures appropriate for your property.These recommendations should be considered when drawing up the property data sheets for identifying the appropriate treatment tomaximise the opportunities under the different funding models such as the Green Deal and local Get me Toasty scheme.


Lo

wC

ar

bo

nH

ou

sin

gR

etr

ofit

23

Wall Types and AppropriateTreatment

Based on the range of 9 archetypesdescribed on page 18, using the as builtwall specifications for the period ofconstruction, a range of wall treatmentshave been shown in Technical Appendix B.The measures described in the table enablethe user to assess the impact of the basicand intermediate treatment measures onthe walls U-values once installed. These arenot by any means exhaustive and in theshort to medium term advice should besought from appropriate designprofessionals before selecting the optimalsolution for a given situation. As the GMstock intelligence data is built up a greater

body of evidence of what works in thesesituations will be available. Eventually userswill be able to select solutions from thisstock intelligence database via the webportal discussed earlier.

Summary

Analysis of the potential for thermalefficiency improvements across the GMhousing stock has identified the following:

• Nine specific archetypes have beenidentified as the most prevalent acrossthe Greater Manchester housing stock.

• Target standards for SAP level linked toEPC band and kgCO2/m

2 are then definedfor three levels of retrofit intervention –Basic, Intermediate and Major.

• These standard levels have beendesigned to match the national 2020 and2050 emissions reductions targets.

• Basic, Intermediate and Major Packagesof measures have been identified for eacharchetype as it was originally built.

It is recognised that property owners areunlikely to undertake a full retrofit of theproperty at the same time. This documentwill help to ensure that an incremental‘whole house’ approach is as efficient andcost effective as possible.

Imag

eby

kind

perm

issi

onof

Ener

gySa

ving

Trus

t


Lo

wC

ar

bo

nH

ou

sin

gR

etr

ofi

t

24

3. Specific ConsiderationsBuilding Regulations and Planning

A further consideration for the designer and/or property owner, when looking at any treatment to external walls, isto take into account the impact the proposed treatment on the existing structure and whether it will meet currentBuilding Regulation requirements.

As a rule of thumb, if the treatment coversmore than 25% of the wall area thenBuilding Regulation requirements will apply;if in doubt check with your local BuildingControl Officer, prior to applying anytreatment.

Whilst our attention in this report is focusedprimarily on wall treatments, this rule ofthumb applies equally to the upgrading ofother ‘retained thermal elements’ such asfloors and roofs.

Improvement works affected by BuildingRegulation control include replacementwindows, external doors with more than 50%glazing, installation of central heating boilersand/or wood burning stoves,new/replacement electrical wiring, and theinstallation of renewable technologies.

Building Regulation requirements are brokendown in two parts, procedural andsubstantive. The procedural requirements inthis instance would be to either useaccredited contractors registered on anationally recognised ‘Competent PersonsScheme - thus allowing them to self certifythat their works comply, or to seek approvaldirectly from a Building Control body. Thesubstantive element is simply a matter ofensuring that the treatment works meet thefunctional requirements of Part L of theBuilding Regulations, details of which areoutlined in the supporting guidance that isApproved Document L1B.

It should be noted that where approval underBuilding Regulations becomes necessary,charges will be applicable for determiningcompliance, unless the work is undertakenunder the auspices of a ‘Competent PersonsScheme’.

The on-going intelligence gathering ofimproved Greater Manchester properties willnot only assist those carrying out the work,the pattern book approach that it will developwill also assist Building Control. As they willnot only be able to contribute to this body of

evidence it will also prove invaluable inassessing applications to ensure that as thepace of retrofit picks up it will not be held upby the statutory procedures.

Planning permission may also be required,particularly for measures that would involvechanges to the external appearance of theproperty. Advice should be sought from thelocal authority.

Risk From Flood Damage

The environmental impact of the risk offlooding is an important consideration whenconsidering any treatment to cavity walls.Flood risk levels for a property can be foundat www.environment-agency.gov.uk

• select the “Home and Leisure” list and

• select “What’s in your backyard“.

• From here you can go straight to a mapand

• enter your “post code” where you will findclear guidance on the likelihood of floodingdamage to your property and in the localarea in general.


Lo

wC

ar

bo

nH

ou

sin

gR

etr

ofit

25

A range of materials are available forinsulating cavity and solid walled properties.Some are more suitable than others in areasof high flood risk, for example; blown mineralfibre filled cavities, if affected by flood waterwill need to have the fibre removed to enablethe drying out process to occur. Propertiesthat are situated in flood risk areas should beinsulated with alternative materials such asbonded EPS beads which drain freely orinjected PUR expanding insulation which canassist in providing an effective water barrieras an integral part of the existing wallconstruction. Guidance from the productmanufacturer should be sought prior toinstallation and consideration given to thebreathability of the resulting wall.

The Greater Manchester Get me Toastycampaign, which promotes Loft and CavityWall Insulation to private householders,should identify flood risk properties as part ofits delivery process and recommend suitablematerials for the affected properties.

Risk from Fire

In England all External Wall Insulationsystems must meet the requirements of theBuilding Regulations approved documents B1(Fire Safety - dwellings) Section B4 (8). Thisdocument can be found at the following link:

http://www.planningportal.gov.uk/uploads/br/BR_PDF_ADB1_2006.pdf

Further guidance and material specificationsis offered by the Insulated Render andCladding Association (INCA):

http://www.inca-ltd.org.uk/pdfs/INCA-Technical-Guide-01-Fire-PR-for-EWI-Systems.pdf

Interstitial and SurfaceCondensation

Condensation is a modern phenomenonaffecting approximately 15% of homes in theUK (BS 5250) and its effect is generallygreater in post-war housing. Condensationmust not be confused with dampness due towater penetration from the outside ordampness caused by the normal drying outof a new building. Condensation, like allforms of dampness, is a particular problembecause damp homes are ‘harder to heat.’

Surface condensation can occur when water

vapour, usually from occupants and theiractivities condenses on an exposed surfaceor interstitial condensation where it is withinthe fabric.

Air containing a large amount of water vapourhas a higher vapour pressure than drier airand therefore moisture from the wetter airdisperses towards drier air. This means thatthe concentration of moist air in a kitchen orbathroom easily disperses throughout adwelling and the moist air at higher pressureinside a dwelling tries to escape by ventilationand through the structure where it maycondense within it.

Air at all temperatures absorbs moisture andthe higher the temperature is the moremoisture it can contain. This air will reach astate when it cannot absorb any more and itwill have therefore have reached saturationpoint. Condensation will occur when thewarm moist air is cooled to its ‘dewpoint’temperature, either by being brought intocontact with cold surfaces or by passing intoa cooler part of the building.

Condensation will also occur on absorbentsurfaces but will not always show until thesurface is very damp. In these cases mouldgrowth can occur consisting of black patcheswhich will cause deterioration of decorativefinishings and potentially health problems forresidents. This type of growth can also formon clothing and shoes etc. stored inunventilated and un-heated built incupboards.

Phot

oco

urte

syof

Prop

erty

Tect

onic

s


Lo

wC

ar

bo

nH

ou

sin

gR

etr

ofi

t

26

The occurrence of condensation is influencedby a number of factors:

1. The number of occupants and theirbehaviour;

2. The type of dwelling and its construction;

3. Heat levels maintained in the property;

4. Type of heating;

5. Length of time the property remainsunheated;

6. Level of insulation and airtightness;

7. Amount of ventilation and

8. Prevailing weather conditions.

To reduce the risk of condensation attentionshould be given to improving ventilation,insulation or heating, or a combination ofthem.

Checklist of considerations:

• Check that condensation is the cause ofthe dampness problem.

• Improve insulation or its continuityparticularly if mould growth is associatedwith cold bridges e.g. uninsulated lintels.This is obviously more expensive thanventilation but the main aims are to keepsurface temperatures above dew point.This measure is linked to heating asinsulation without a suitable heat input will

not provide a satisfactory remedy.Double glazing windows will reduce theoccurrence of surface condensation.

• Provide extract ventilation preferably at

source and possible with humidistat

controlled extractor fans in kitchens and

bathrooms. A limited amount of ventilation

is essential to keep the relative humidity

below 70%, achieving a level below 55%

will also ensure that dust mites are

eliminated. Ventilated hoods above

cookers are particularly useful in extracting

steam generated by cooking. Kitchen and

bathroom doors should be well fitting to

prevent moist air entering cooler rooms.

The amount of openable window (where

provided) should be in line with part F of

the current Building Regulations.

• Ventilate unheated internal stores on

external walls.

• Provide background ventilation by e.g.

trickle ventilators.

• Advise occupants about activities that can

promote condensation and mould growth

e.g. flue less heaters, unvented tumble

driers, excessive indoor clothes drying, and

failure to use/blocking off ventilators.

Clothes drying should be in heated and

well ventilated spaces.

References in Appendix C

Ventilation and Building Physics

When a property is retrofitted to make itmore energy efficient, by improving airtightness to prevent heat loss along with highlevels of wall insulation, there is a need toconsider the flow of moisture through andout of the building. Adequate ventilation isessential to ensure that condensation doesnot become a problem either within thebuilding fabric (a) or within the rooms (b).

a. Moisture trapped and condensing withinthe building roof or walls is known asinterstitial condensation and can causerot, mould and fungal growth.Calculations should be carried out toensure that this does not happen. Thereare some circumstances such as in stonebuildings and some solid wall properties



Lo

wC

ar

bo

nH

ou

sin

gR

etr

ofit

27

where it is advantageous to the buildingfabric for materials to be used that allowmoisture to pass through them.

b. Moisture and stale air from the activitieswithin the home will also need to beremoved both for comfort and forminimisation of allergens such as dustmites. With all the draughts removed thislevel of ventilation will need to bedesigned in. The greater the level ofinsulation the more the ventilationbecomes a whole house solution. This canbe done using passive stack ie’ (no fans)using the buoyancy of the warm air or byMechanical Ventilation with Heat Recovery(MVHR) where a fan pushes the airthorough a heat recovery unit.

The installation of the more expensive heatrecovery measures would generally only beintroduced into a property that hasundergone both the basic and intermediatemeasures recommendations. A propertywhich has undergone such extensive workscan be affected by a restricted air flow whichmay result in the property suffering frominternal condensation.

Moisture in a home is produced principallyby:

1. Bath and shower use,

2. Cooking or

3. Drying clothes indoors or

4. Running an unvented tumble dryer.

Residents may be tempted in thesesituations to open doors or windows to allowthe moisture-laden air to escape, which willalso cause the property to lose heat. It isrecommended that the designer shouldconsider the replacement of ordinary fanswith the installation of new low voltage MVHRextractor fans within the kitchen andbathroom. Modern replacement fans havebeen developed to recover up to 85% of theheat loss during the extraction of the moistair from the room and at the same time bringin fresh air from the outside that is partiallyheated during the heat exchange process.An alternative would be a fully ductedventilation system throughout the propertyeither using a passive stack or with the unitlocated in the loft area that would allow theheat recovery to take place during the airexchange process. This option would beconsiderably more expensive.

Design Considerations

Designers of retrofit works will be aware thatalthough the walls, roof and floor elementsare the primary consideration when lookingat energy efficiency, specific technicaldeterminants such as eaves details, integralgarages, extensions, rooms in the roof andvelux windows will all need to be consideredon a case by case basis.

It is hoped that this document will allowretrofit designers and property owners toadopt a sensible and cost effectivemethodology for assessing the mostappropriate measures to install and the mostsuitable order in which to undertake the work.

Image by kind permission of Energy Saving Trust


Lo

wC

ar

bo

nH

ou

sin

gR

etr

ofi

t

28

There is also a need to consider the effect ofinstalling insulation to an existing wallstructure when considering the generalspecification and performance calculationsfor the U-value. A before and after calculationto establish the dew point should be carriedout by the designer to see if the insulationwill cause any interstitial condensation withinthe existing materials. As noted above failureto do so could lead to mould growth, rot andfungi growth occurring within or on thestructure behind the newly installedinsulation material.

Sustainability and the Home

The Retrofit Standards and HousingIntelligence Groups have taken theopportunity to set out the full range ofmeasures which can be applied to provide asustainable living environment. The listshown in Appendix A includes an extensivereview of measures that can have aconsiderable impact on the following:

• Energy Usage

• Water Usage

• Behavioural Change

• CO2 emissions.

Individual users should consider that in futurethere will be ever increasing demands placedon both energy and water supplies. While theintroduction of new technologies may help, itis recognised that changing our behaviourregarding how we use these scarceresources will make significant savings to a

household’s energy consumption, financialexpenditure and carbon footprint.

Users are recommended to read the ‘MissingQuarter’ report which includes clearguidance on ensuring that behaviour changeadvice is included in any retrofit project orprogramme. It is commonly recognised thatup to 25% of the annual cost of a typicalhome’s energy bill can be saved by adoptinga different approach to energy use.

Technology Advancement

As with all advances in the field of energyefficiency the current range of products inthe marketplace will have a varied impact onreaching the design standards required.Users need to be aware that, due torestrictions on available space within thehome, it may not always be possible toincorporate some products. As thetechnology advances, and improvements aremade to the products performance andoverall size, such restrictions may beovercome. New products will continue toenter the market as the technology develops

through increased innovation. It is anticipatedthat some of the older and harder to treatstock will be able to reach the 2050 target ofan 80% reduction in their annual CO2

emissions, in a more cost effective andaffordable way as a result of such innovations.

This process will be streamlined at the GreaterManchester wide level by developing andusing the stock intelligence database and webportal noted earlier. This will allowdevelopment and testing of new products, plusthe effective dissemination and use of bestpractice information across the whole area.

Summary

This section will allow property owners andretrofit programme designers to assess theirschemes against a range of specific issueswhich will affect all or some of the GreaterManchester housing stock.The topics above are not designed as acomprehensive list of issues but will providea useful check list of specific considerationsfor any proposed works.

Image courtesy of C. Baker Image by kind permission of Energy Saving Trust


Lo

wC

ar

bo

nH

ou

sin

gR

etr

ofit

29

The research and standards reviewcarried out for this report has led tothe following conclusions andrecommendations.

These will enable a Common Standard andFramework of retrofit measures to beadopted across all areas and organisations inGreater Manchester, yielding substantialfinancial savings and a pathway for achievingthe national carbon emissions targets in thedomestic housing retrofit sector.

1. With 1.1 million homes which areproducing more than a third of the CO2

emissions in Greater Manchester, thedeveloping Green Deal represents asignificant opportunity for householdersand landlords to improve the energyefficiency of their properties. This willcontribute significantly towards therecently adopted Greater ManchesterClimate Change Strategy target of48% carbon emissions reduction by2020, which exceeds the nationaltarget of 34%.

2. A review of the housing stock hasidentified 9 major archetypes ofproperties to aid understanding of whatis required.

3. A potential for energy efficiencyimprovement for each archetype to reachthe national carbon emissions reductiontargets of 34% by 2020 and 80% by2050, has been identified in the form of

a SAP rating linked to an EnergyPerformance Certificate and theassociated amount of carbon per metersquared for that property type.

4. Each of these SAP target standards havethen been analysed and a suite of energyefficiency measures designedappropriate to each archetype, identifiedas basic, intermediate (2020 target) andmajor interventions (2050 target).

5. A full evaluation of the cost and energyrating of each measure is included in theTechnical Appendices.

6. Crucially information is also includedindicating the most efficient and costeffective order in which to install thesemeasures using natural trigger pointswithin the lifespan of the property and it’sownership. Examples of these triggerpoints would include such works as anew roof, new windows, kitchen/bathroom upgrades or an extension.Lifestyle changes are also recognised asappropriate trigger points, includingmoving home, increased or reducedfamily size or occupancy.

7. It is recognised that property owners areunlikely to undertake a full retrofit of theproperty all at once; this document willhelp to ensure that an incremental‘whole house’ approach is as efficientand cost effective as possible.

8. These levels of SAP/EPC/kg CO2 targetsgive property owners the option toupgrade the energy efficiency to thehighest level possible during plannedwork to avoid potential wasteful andcostly revisiting of the same areas lateron when the higher levels are likely to berequired.

9. A range of specific buildingconsiderations are discussed to ensureusers of this document are informed ofkey issues that are important in anyretrofit planning.

10. It is made clear that in order to reachthese very stretching national targets for2050 all the properties which alreadyexist in Greater Manchester will requiresome form of retrofit to ensure they meetthe energy efficiency standards requiredto achieve the 80% emissions savings.

11. Finally it is also acknowledged that someof the SAP/EPC/kg CO2 targetsrecommended will have to takeadvantage of newly developingtechnologies that may not be fullyavailable yet.

12. Development of a Greater Manchesterweb portal and database of thesearchetypes and retrofit solutions couldeffectively be linked to the BuildingResearch Establishment (BRE) NationalRefurbishment Centre12 and the NationalEnergy Efficiency Data-Framework(NEED).13

12www.rethinkingrefurbishment.com13http://www.decc.gov.uk/assets/decc/11/stats/energy/energy-efficiency/2078-need-data-framework-report.pdf

4. Conclusions


Lo

wC

ar

bo

nH

ou

sin

gR

etr

ofi

t

30

Recommendations for this report were developed following the compilation of evidence by the GM Housing RetrofitStandards Group and the associated stakeholder seminar held in July 2010. The recommendations should beadopted to maximise the potential benefits of physical housing retrofit programmes and to endorse long termenergy efficiency changes in behaviour.

The following recommendations are made to inform those responsible for developing strategy and implementing domestic retrofit programmesin both the private and social sector.


Social Landlords • That Social Landlords should take into consideration the recommended SAP/EPC/kg CO2 standards whendeveloping, tendering or managing retrofit schemes.

• That they should also take these standards into consideration when preparing future asset plans andmaintenance budgets.

• To link these standards and targets to planned maintenance ‘trigger points’ such as kitchen/bathroom upgradesor new windows etc, to ensure effective long term cost efficiencies.

• Take into consideration the items included in the specific considerations section when planning or tendering aproject.

Local Authorities • Local Authorities to recommend these SAP/EPC/kg CO2 standards to all social landlords, retrofit developers andprivate householders through the Planning and Building Control services.

• To work with private landlords and Landlords Associations to promote the installation of measures to improve theenergy efficiency for the private rented stock. This will include promotion through the landlords forums, the GreaterManchester Landlords Accreditation Scheme and where appropriate, active enforcement under the provision of theHousing Act 2004.

• That householders be proactively made aware of these standards and opportunities for funding linked to the GreenDeal/FITs/RHI etc when contact is made with the sustainability/housing or affordable warmth departments.

Retrofit Developers • That developers, builders and designers include these standards in any retrofit schemes undertaken in GreaterManchester.

• That the higher level standards are recommended to ensure effective long term cost efficiencies for the owners.

• Be aware of the potential for linking Green Deal and other local and national funding to these standards.

• Take into consideration the items included in the specific considerations section when planning or tendering aproject.

5. Recommendations


Lo

wC

ar

bo

nH

ou

sin

gR

etr

ofit

31


Scheme Managers • To ensure that these standards are embedded in the project management and work plans.

• To be aware of the potential for reaching the higher standards when retrofitting at a natural ‘trigger point’, ratherthan costly revisiting at a later date.

Homeowners • To use this document to help plan the most efficient and effective energy efficient retrofit programme for their home,to ensure an incremental ‘whole house’ approach is used where possible.

• That these standards are included in the contract documentation for any scheme or project.

• Take into consideration the items included in the specific considerations section when planning or contracting aproject.

Low CarbonHousingRetrofit/LCEAcommittee

• To carry out an annual review of this report in light of developments in retrofit technology and funding models suchas the Green Deal. This will ensure that this document remains relevant and provides appropriate recommendedstandards up to 2020.

Large scaleSchemeDevelopers/Installers

• The Greater Manchester wide Toasty scheme should take flood risk factors into account prior to recommendingspecific materials for CWI.

• To monitor the developments in domestic energy efficiency and retrofit technologies and encourage trial pilotschemes where appropriate.

• To create the photo library of front elevations and develop the Greater Manchester Retrofit Housing Web Portal andDatabase to allow users to access the archetypes and measures packages as well as measuring progress towardsthe emissions reduction targets.


Lo

wC

ar

bo

nH

ou

sin

gR

etr

ofi

t

32

Greater Manchester Low Carbon EconomicArea Retrofit StandardsTECHNICAL APPENDICES

Appendix A:

Typical range of measures which can be utilised to enhance the properties sustainability and energy performance

Green = Basic Measures Amber = Intermediate measures Purple = Major Measures Blue = Whole House Sustainable

*Costs based on 2010 figures

Sustainability and Energy Measures Aim Quantity Unit Rate* Cost*

Undertake a before and after EPC certificate 2 No £60.00 £120.00

Air tightness test to establish leakage 2 item £60.00 £120.00

Draught stripping all doors and windows 100 m £1.30 £130.00

Lay hardboard covering over floor boards to prevent air leakage 6mm thick 140 m2 £10.00 £1,400.00

Option A - Loft top up insulation to minimum 270mm laid between ceilingrafters and on hatch to achieve set U-value 0.16W/m2K 50 m2 £6.00 £380.00

Option B - loft top up insulation to 400mm, replace loft hatch 0.1W/m2K 50 m2 £10.00 £500.00

Cavity wall insulation 0.35W/m2k 80 m2 £4.00 £320.00

Option A - External wall insulation 0.35W/m2k 80 m2 £72.00 £5,760.00

Option B - external wall insulation - foam @approx 100mm, fibre 120mm 0.25W/m2/K 80 m2 £86.00 £6880.00

Option C - external wall insulation - foam @approx 175mm, fibre 220mm 0.15W/m2/K 80 m2 £100.00 £8000.00

Provide 100% low energy light bulbs fitted internally and externally 10 No £5.00 £50.00

Option A – Internal insulation - Dry lining of all external walls to achieveminimum U-value 0.35W/m2k 80 m2 £45.00 £3,600.00

Option B – Internal insulation - Dry lining of all external walls to achieveintermediate U-value 0.25W/m2k 80 m2 £65.00 £5,200.00

Option A - Install double glazed PVCu windows 1.7W/m2k 9 No £350.00 £3,150.00

Option B - Install double glazed gas filled PVCu windows 1.5W/m2k 9 No £ 375.00 £3,375.00

Option C - Install triple glazed PVCu windows 0.9W/m2k 9 No £420.00 £3,780.00

Option D - Install composite frame triple glazed windows 0.7W/m2K 9 No £550.00 £4,950.00

Option A - Install new insulated PVCu doors (Solid / 50% glazed doors) 1.7W/m2k 2 No £550.00 £1,100.00

Option B - Install new insulated PVCu doors (Solid / 25% glazed doors) 1.0W/m2k 2 No £650.00 £1,300.00

Option A - Overlay existing ground floor with 25mm insulated boarding 10mm thick 70 m2 £12.00 £840.00


Lo

wC

ar

bo

nH

ou

sin

gR

etr

ofit

33

Sustainability and Energy Measures Aim Quantity Unit Rate* Cost*

Option B - Take up ground floor boards and insulate between joists andrelay to achieve 0.7 U-value 70 m2 £35.00 £2,450.00

Option C - Dig out trench around external walls and put in recycledfoamed glass pumice insulation (Misapor) to achieve 0.45W/m2/K U-value 20 m £70.00 £1,400.00

Option D - Take up ground floor boards as option B and insulate trencharound external walls as option B to achieve 0.25W/m2/K U-value 20 m £65.00 £1,300.00

Install Smart meter data display for monitoring energy usage 1 No £65.00 £65.00

Voltage optimisation install a Voltage optimisation meter 1 No £ 400.00 £400.00

Upgrade heating controls including new thermostat programmer in linewith CHeSS (2005) 1 item £120.00 £120.00

Thermostatic radiator valves fitted to all radiators 7 No £ 25.00 £175.00

Install A rated condensing boiler fitted with low levels of NOx 1 No £1,800.00 £1,800.00

Aerated showerhead flow restrictor to reduce flow rate 8 ltr/min 1 item £15.00 £15.00

Alternative to electric shower, install thermostatic mixer taps which cancontrol shower temperature fed direct from combi boiler.

Removescaldingpotential

1 item £345.00 £345.00

Spray taps and flow regulators provided for wash hand basins and kitchensink 8 ltr /min 3 No £85.00 £255.00

SAP Appendix Q extractor fans fitted whole house including bathroom andkitchen 2 No £170.00 £340.00

Install heat recovery system by installing ventilation within house andsystem in loft 1 item £1,350.00 £1,350.00

Option A - Install 2 panel solar thermal system and 215 ltr indirect twincoil cylinder to existing heating system to provide hot water 2No 1 Item £3,500.00 £3,500.00

Option B - Install 2 x 20 evacuated tube solar thermal system as above 2No 1 item £4,300.00 £4,300.00

Option C - install 4 x 20 tube evacuated tubes and twin coil solar thermalstore 4No 1 item £7,150.00 £7,150.00

Option A - Solar photovoltaic panel to provide electricity for lights andappliances 1.1KWp 1 item £4,500.00 £4,500.00

Option B - Solar photovoltaic panel to provide electricity for lights andappliances 2.1KWp 1 item £5,200.00 £5,200.00

Option C - Solar photovoltaic panel to provide electricity for lights andappliances 3.9KWp 1 item £6,500.00 £6,500.00

Install Electric shower 8.5kW 1 item £145.00 £145.00

Fit new bath sized 156ltr 1 item £275.00 £ 275.00

Duel flush WC cisterns 4/2 ltr 2 No £65.00 £130.00

Target water usage to meet the set levels of 115 ltr per person per day Goal 1 item £20.00 £20.00

Water butt for non potable water 200ltr 1 item £225.00 £225.00

Recycling water for WC cistern usage 100ltr 1 item £195.00 £195.00

Monitor water rate flow before and after 2 item £45.00 £90.00

External clothes rotary dryer fitted 1 No £65.00 £65.00

Composting bin supplied 1 No £75.00 £75.00

Waste storage and recycling area as defined by BS 5906 3No bins 1 item £320.00 £320.00

General sustainable homes guide and operational manual 1 item £20.00 £20.00


Lo

wC

ar

bo

nH

ou

sin

gR

etr

ofi

t

34

Wall U-values and ImprovementsBased on Applied InsulationMeasures –

Appendix B

Walls are particularly complex whenconsidered for energy efficiencyimprovements, with a number of differentcommon wall construction designs, andseveral treatments that can be applied toimprove the thermal efficiency. To assist in

demonstrating the effectiveness of the thesevarious treatments, the following illustrationshave been provided as a guide to the typicalU-values that may be obtained for differingtypes of wall construction, from the ‘as built’construction.

This level of detail has not been included forother property elements such as roofs andfloors as these have a much smaller range ofretrofit options.

• The solid wall construction referred to inarchetypes 1 to 4 is covered in Type “A” to“C” treatments.

• Cavity wall construction referred to inarchetypes 5 to 8 is covered by Type “D” to“E” treatments.

• Solid wall treatment referred to in Type “F”would be applicable in system builtproperties referred to in archetype 9.

TECHNICAL APPENDICES

1 2 3

Wallconstruction

existingW/m2K-1

1st visit(basic orinterim)

target0.35W/m2K-1

forecastU-valueW/m2K-1

2nd visit target0.15W/m2K-1


A

25mm plaster,on 215mmbrick wall

fermacelboard fixed tointernal wallthrough30mm aerogelinsulation

add rendered30mmphenolicfoam bondedto 30mmaerogel fixedto wall withplastic pinfixings

215mm solid wall 2.03 IWI part 0.36 EWI to finish 0.16

B

25mm plaster,on 215mmbrick wall

internalsmooth coatpolymerrender vapourcontrol layeron 100mmwoodfibre

add externalpolymerrender on160mmwoodfibreinsulationfixed direct toexternal wall

215mm solid wall porousbrickwork 2.03 IWI part 0.37 EWI to finish 0.16

C

25mm plaster,on brick +half wall

plastered55mmphenolic foamon base coaton internalface

add polymermodifiedrender on120mmmineral woolon externalface fixed withplastic pinfixings

340mm solid wall 1.30 IWI part 0.33 EWI to finish 0.16

Inside Outside

Produced in partnership with Urbed


Lo

wC

ar

bo

nH

ou

sin

gR

etr

ofit

35

There are a substantial range of productsavailable which could equal or better theperformance of the products used in thesecalculations. When undertaking a formaltechnical assessment the designer shouldmake their recommendations based on theproducts offering the highest achievableperformance and value for money to the enduser. The designer will have to bear in mindthat the cost of the works to be undertaken

will have to be repaid back from the savingsachieved through the ongoing energy bill.

Designers should consider the insulationsmaterials available and assess theperformance criteria in use. There arevarious manufactured products availablethat will meet all the possible designcriteria requirements along with more naturaland sustainable products such as sheep’swool etc.

4 5 The specifications here are not the onlysolutions, only suggestions for somescenarios. These are described briefly hereas an aid.

single visit -external

target0.2W/m2K-1


single visit -internal

target0.25W/m2K-1


rendered50mmphenolic foambonded to30mmaerogel fixedto wall withplastic pinfixings

fermacelboard fixed tointernal wallthrough50mm aerogelinsulation

These measures suit a wall with feature internalplaster or limited space so an insulant at or nearthe thickness of the existing plaster is requiredinternally.

Further advice should be sought before using a nonpermeable external insulant on old buildings eg. ifthere is timber within the construction of the wall.

full EWI 0.20 full IWI 0.26

externalpolymerrender on180mmwoodfibreinsulationfixed direct toexternal wall

internalsmoothcoat polymerrender vapourcontrol layeron 150mmwoodfibre

Where there are issues as above and such as withlime mortar and porous bricks a vapour permeableinsulant should be used. Wood fibre also haswicking properties as well as carbon sequestrationand renewable advantages but it is costly.


polymermodifiedrender on160mmmineral woolfixed toexternal facewith plasticpin fixings


Phenolic foam can be used internally as it is muchless toxic in a fire. Mineral wool offers vapourpermeability at a lower cost but without otheradvantages. There are technical issues with itself-supporting at high thicknesses.



Lo

wC

ar

bo

nH

ou

sin

gR

etr

ofi

t

36


Appendix B (continued)

1 2 3

Wallconstruction

existingW/m2K-1

1st visit(basic orinterim)

target0.35W/m2K-1


2nd visit target0.15W/m2K-1


D

20mm plaster,2 standardbrick courses,25mm cavity

injected cavityfill, graphitecoatedpolystyrenebead achieves0.79 W/m2K

add externalpolymerrender on220mmwoodfibreinsulationfixed direct toexternal wall

250mm small cavity wall 1.37 IWI part 0.79 EWI to finish 0.16

E

15mm plaster,2 standardbrick courses,50mm cavity

injected cavityfill, graphitecoatedpolystyrenebead achieves0.49 W/m2K

add polymermodifiedrender on105mmphenolic foamon base coaton externalface

275mm cavity wall 1.39 cavity fill 0.51 EWI to finish 0.15

F

20mm renderon 200mmwimpeyno-fines with15mm plaster

polymermodifiedrender on100mmmineral woolexternalinsulation

add plastered85mmphenolicfoam on basecoat oninternal face

non-trad 2.58 EWI part 0.37 IWI to finish 0.15

Inside Outside


Lo

wC

ar

bo

nH

ou

sin

gR

etr

ofit

37

4 5 The specifications here are not the onlysolutions, only suggestions for somescenarios. These are described briefly here asan aid.

single visit -external

target0.2W/m2K-1


single visit -internal

target0.25W/m2K-1


externalpolymerrender on180mmwoodfibreinsulationfixed direct toexternal wall

internalsmoothcoat polymerrender vapourcontrol layeron 140mmwoodfibre

There may be little advantage to insulating cavitiesthis small and going straight to the external wallinsulation. Where there are issues with moisture ina property, wicking permeable external insulantswill assist in creating a better internal environmentas well as insulating the property.


polymermodifiedrender on100mmphenolic foamon base coaton externalface


Where there is a big enough cavity for any moisturecondensing in the cavity to run to ground and alsoso there is clear separation between internal andexternal leaf, phenolic foam is a cost effectiveinsulation method due to its low thermalconductivity.


rain-screencladding onproprietarysupport railswith 200mmmineral woolinsulationbetween

fermacelboard onbattens with20mm rubbercoatedVacuuminsulatedpanelsbetween onlevellingbasecoat

The assumption here is that in non trad propertiesmovement and cracking mean that it is inadvisableto put vapour impermeable insulants on the outsideof the property however as vapour pressure isalmost always outward foams are suggested here.



Lo

wC

ar

bo

nH

ou

sin

gR

etr

ofi

t

38

Appendix C:

References & Sources

1. Department for Energy and ClimateChange: http://www.decc.gov.uk/

2. Energy Saving Trust:http://www.energysavingtrust.org.uk/

3. Building Research Establishment:http://www.bre.co.uk/

4. Greater Manchester Climate ChangeStrategy:http://www.agma.gov.uk/cms_media/files/gm_climate_change_strategy_final1.pdf

5. The Building Regulations Part L1B,October 2010.http://www.legislation.gov.uk/uksi/2010/2214/contents/made

6. Sustainable refurbishment CE 309,Energy Saving Trust.http://www.energysavingtrust.org.uk/business/Business/Housing-professionals/ Existing-housing/House-types

7. Detailed House type scenarios includingEPC/CO2 and financial savings for 8principle archetypes:http://www.energysavingtrust.org.uk/Publication-Download/?oid=1532044&cg=bestpracticedocs&ci=energyst

8. Moving Beyond the Decent HomesStandard 2009, Sustainable HousingAction Partnership.http://www.shap.uk.com/

9. Greener Homes for Redbridge, Propertyportfolio.http://www.east-homes.co.uk/CMSPage.aspx?ssbid=2987

10. Domestic low and zero carbontechnologies: CE 317, Energy SavingTrust:http://www.energysavingtrust.org.uk/business/Global-Data/Publications/CE-317-Domestic-low-and-zero-carbon-technologies

11. Energy Saving Trust publicationsincluding: Materials Chart: CE71http://www.energysavingtrust.org.uk/business/Business/Housing-professionals/Publications-and-case-studies

12. National Refurbishment Centre and Portal:http://www.rethinkingrefurbishment.com/

13. Old Homes Super Homes:http://superhome.urbed.coop/

14. Retrofit for the Future:http://retrofitforthefuture.org/viewproject.php?id=186

15. Isothane Ltdhttp://www.isothane.com/

16. Vent Axia Ltdhttp://www.vent-axia.com/

Interstitial and surface condensationreferences

17. British Standard 5250: Code of Practicefor Control of Condensation in Buildings,2002 and revisions, BSI.

18. Garratt, J and Nowak, F, Tacklingcondensation, BRE Report 174 (BR 174),Building Research Establishment,Watford, 1991.

19. The Building Regulations Part F,October 2010



Lo

wC

ar

bo

nH

ou

sin

gR

etr

ofit

39

Appendix D: Glossary of terms

Glossary of Terms

AGMA Association of Greater ManchesterAuthorities

BRE Building Research Establishment

BS British Standard

CERT Carbon Emission Reduction Target

CESP Community Energy SavingProgramme

CHP Combined Heat and Power

CO2 Carbon Dioxide

CWI Cavity Wall Insulation

DEA Domestic Energy Assessor

DECC Department of Energy and ClimateChange

ECO Energy Company Obligation

ELENA European Local Energy Assistance

EPC Energy Performance Certificate

EPS Expanding Polystyrene

ERDF European Regional DevelopmentFund

EST Energy Saving Trust

FiTs Feed-in Tariffs

GM Greater Manchester

KW Kilo Watts

KWh Kilo Watt Hours

LSOA Local Super Output Areas

MCC Manchester City Council

mm millimetres

MVHR Mechanical Ventilation and HeatRecovery

NHER National Home Energy Rating

OFGem Office of the Gas and ElectricityMarkets

PUR Polyurethane Foam

PVCu Polyvinyl Chloride Un-plasticised

PV Photovoltaic

RHI Renewable Heat Incentive

RDSAP Reduced Data Standard AssessmentProcedure

SAP Standard Assessment Procedures

SWI Solid Wall Insulation

TRV Thermostatic Radiator Valve

U-Value Measure of thermal efficiency of abuilding element


Low Carbon Housing RetrofitGreater Manchester

Published by City South Manchester Housing Trustfor the Retrofit Standards Group

Printed by ERDF NW, Northwards Housing, Salford University andWigan and Leigh Housing for the Retrofit Standards Group


Transforming homes from G to A - the University of · PDF fileTransforming homes from G to A...

Documents

Transcript of Transforming homes from G to A - the University of · PDF fileTransforming homes from G to A...