131263_City-South_Manchester_v5__ 19/03/2012 12:00 Page 1
Transforming
homes from G to A
Low Carbon Housing Retrofit
1
An assessment of the archetype
requirements and recommendations for
improving the energy efficiency of
dwellings in Greater Manchester
Low Carbon Housing Retrofit
Greater Manchester
131263_City-South_Manchester_v5__ 19/03/2012 12:00 Page 2
Foreword
Over the past few years there has been a growing recognition of the magnitude of the challenge that the
UK and the rest of the world is facing in terms of meeting carbon emissions reduction targets.
Emissions related to domestic housing account for over
Greater Manchester features many stakeholders fully
25% of our overall output and so housing has a critical
committed to the housing retrofit agenda – this document
role to play in contributing to the wider goals.
will assist as initiatives such as Green Deal and the new
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
Energy Company Obligations are implemented and help
GM along the way towards its ambitious 2050 emission
reduction goals for housing.
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.
Ashley Crumbley
Acknowledgements
Low Carbon Housing Retrofit
2
Tom Rock, (Chair)
Alan Foster,
Andy Kippax,
Andy Morris,
Charlie Baker,
Gavin Summerson,
Michael O’Doherty,
Paul Maidment,
Richard Hartless,
Ross Hall,
Shona Thomas,
Stephen Passmore,
Stephen Todd,
Steve Parlby,
Tim Barwood,
Tony Baldwinson,
William Swan,
City South Manchester Housing Trust
Homes and Communities Agency (HCA)
Stockport Metropolitan Borough Council
Bolton at Home
Urbed
Building Research Establishment
Manchester City Council
Northwards Housing
Building Research Establishment
Building Research Establishment
Greater Manchester Low Carbon Housing Retrofit Programme
Energy Saving Trust
Salford University
Irwell Valley Housing Association
Greater Manchester Low Carbon Housing Retrofit Programme
NW Centre for Construction Innovation
Salford University
Image courtesy of Manchester City Council
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Contents
Executive Summary and Recommendations
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 Measures
B: Wall U-Values and Improvements
C: References and Sources
D: Glossary of technical terms
Low Carbon Housing Retrofit
1 Developing a Housing Retrofit Standard
for 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
3
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Executive Summary and Recommendations
Introduction
As we move closer to the Government’s launch of the Green Deal in autumn 2012, it is important for the Association
of Greater Manchester Authorities (AGMA) to ensure they are in a position to deliver the best advice and maximise
the 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 the
Green Deal has to offer to GM residents.
Low Carbon Housing Retrofit
4
In order to achieve this key housing retrofit
stakeholders, operating through AGMA’s
Environment Commission, have started
bringing together a set of independent
recommendations and technical advice that
is relevant to GM’s housing stock
characteristics, which will help to underpin
the specifying and planning of retrofit
projects. In order to maximise the impact of
Green Deal uptake and provide a route to
meeting the local and national emissions
reduction challenge for GM, this Greater
Manchester Housing Retrofit Design
Guidance has been developed.
Aims of the report
There are more that 1.1 million homes in
Greater Manchester which contribute 36% of
the CO2 emissions for the area1. This
provides a significant challenge and
opportunity to target domestic housing in
order to meet the local and national
emissions reduction targets.
It is intended that this report will enable all
users, from individual householders to large
scale landlords and those involved in
planning and installing retrofit measures, to
understand the potential range of energy
efficiency measures that may be fitted to
their properties and the most efficient order
in which to install them. In addition to
applying the basic, intermediate and major
measures, the users’ opportunity for saving
money by reducing their ongoing energy
usage is highlighted. These
recommendations and packages of
measures are linked to the Greater
Manchester Climate Change Strategy2
emissions reduction target of 48% by 2020,
and the national targets of 34% by 2020 and
80% by 2050.
The principle aim is to maximise the
installation of domestic retrofit measures by
maximising the take up of new and future
funding mechanisms such as the Green
GM Low Carbon Housing Retrofit Strategy – discussion draft
Greater Manchester Climate Change Strategy: http://www.agma.gov.uk/cms_media/files/gm_climate_change_strategy_final1.pdf
1
2
Deal, Energy Suppliers Obligation (ECO) and
the local ‘Get me Toasty’ insulation scheme
and to ensure that such investment produces
both employment opportunities for its
residents and starts to address the
increasing issue of those in, or moving into,
fuel poverty.
The Retrofit Strategy endorses the ‘Fabric
First’ model for this programme.
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1
2
3
Low Carbon Housing Retrofit
Fabric first!
The GM energy hierarchy approach
1. Investment should first be made to reduce energy use - by improving
the 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 in
each home by investment in energy monitoring devices and simple
measures such as master switches.
3 Then investment can be made in reviewable energy technologies to
supply the remaining energy needs (e.g. solar photovoltaics, biomass
boilers).
5
Diagram from GM Retrofit Strategy draft
The wide ranging research and standards
review carried out for this report has led to
the following conclusions and
recommendations. These will enable a
Common Standard and Framework of retrofit
measures to be adopted across all areas and
organisations in Greater Manchester, yielding
substantial financial savings and a providing
a pathway for achieving the local and
national carbon emissions targets in the
domestic housing retrofit sector.
Image by kind permission of Energy Saving Trust
The scope of this report is limited to the
range of actions appropriate for the physical
structure of the dwelling, which are seen as
the critical first stage for the GM energy
hierarchy as show in this diagram.
Behavioural Change, Health/Fuel Poverty, and
Skills/Training are addressed in other work
groups as part of the overall Housing Retrofit
programme.
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The report concludes that
1 With 1.1 million homes which are
producing more than a third of the CO2
emissions in Greater Manchester, the
developing Green Deal represents a
significant opportunity for householders
and landlords to improve the energy
efficiency of their properties. This will
contribute significantly towards the
recently adopted Greater Manchester
Climate Change Strategy target of 48%
carbon emissions reduction by 2020,
which exceeds the national target of 34%.
2 A review of the housing stock has
identified nine major archetypes of
properties to aid understanding of what
is required.
Low Carbon Housing Retrofit
6
3 A potential improvement required for each
archetype to reach the national carbon
emissions reduction targets of 34% by
2020 and 80% by 2050, has been
identified in the form of a SAP rating
linked to an Energy Performance
Certificate and the associated carbon
emissions per meter squared for that
property type.
4 Each of these SAP target standards have
then been analysed and a suite of energy
efficiency measures designed appropriate
to each archetype, identified as basic,
intermediate (2020 target) and major
interventions (2050 target).
5 A full evaluation of the cost and energy
rating of each measure is provided in the
technical appendices.
6 Crucially information is also included
indicating the most efficient and cost
effective order in which to install these
measures using natural trigger points
within the lifespan of the property and it’s
ownership. Examples of these trigger
points would include such works as a new
roof, new windows, kitchen/bathroom
upgrades or an extension. Lifestyle
changes are also recognised as
appropriate trigger points, including
moving home, increased or reduced
family size or occupancy.
7 It is recognised that property owners are
unlikely to undertake a full retrofit of the
property all at once; this document will
help to ensure that an incremental ‘whole
house’ approach is as efficient and cost
effective as possible.
8 The levels of SAP/EPC/kg CO2 targets
give property owners the option to
upgrade the energy efficiency to the
highest level possible during planned
work to avoid potential wasteful and
costly revisiting of the same areas later on
when the higher levels are likely to be
required.
www.rethinkingrefurbishment.com
http://www.decc.gov.uk/assets/decc/11/stats/energy/energy-efficiency/2078-need-data-framework-report.pdf
3
4
9 A range of specific building
considerations are discussed to ensure
users of this document are informed of
key issues that are important in any
retrofit planning.
10 It is made clear that in order to reach
these very stretching national targets for
2050 all the properties which already
exist in Greater Manchester will require
some form of additional retrofit to ensure
they meet the energy efficiency standards
required to achieve the 80% emissions
savings.
11 Development of a Greater Manchester
web portal and database of these
archetypes and retrofit solutions could
effectively be linked to the Building
Research Establishment (BRE) National
Refurbishment Centre3 and the National
Energy Efficiency Data-Framework
(NEED)4.
12 Finally it is also acknowledged that some
of the SAP/EPC/kg CO2 targets
recommended will have to take advantage
of newly developing technologies that
may not be fully available yet in order to
be cost effective.
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Recommendations
Recommendations for this report were developed following the compilation of evidence by the GM Housing Retrofit
Standards Group and the associated stakeholder seminar held in July 2010. The recommendations should be
adopted to maximise the potential benefits of physical housing retrofit programmes and to endorse long term
energy efficiency changes in behaviour.
The following recommendations are made to inform those responsible for developing strategy and implementing domestic retrofit programmes
in both the private and social sector.
Recommendation
Social
Landlords
• 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 maintenance
budgets.
• To link these standards and targets to planned maintenance ‘trigger points’ such as kitchen/bathroom upgrades or new
windows/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.
Local
Authorities
• Local Authorities to recommend these SAP/EPC/kg CO2 standards to all social landlords, retrofit developers and private
householders through the Planning and Building Control services.
• To work with private landlords and Landlords Associations to promote the installation of measures to improve the energy
efficiency for the private rented stock. This will include promotion through the landlords forums, the Greater Manchester
Landlords 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 Green
Deal/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 Greater
Manchester.
• 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.
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’, 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 scale
Scheme
Developers/
Installers
• The Greater Manchester wide Get me Toasty scheme should take flood risk factors into account prior to recommending
specific materials for CWI.
• Low Carbon Housing Retrofit/LCEA committee.
Low Carbon • To carry out an annual review of this report in light of developments in retrofit technology and funding models such as
Housing
the Green Deal. This will ensure that this document remains relevant and provides appropriate recommended standards
Retrofit/LCEA
up to 2020.
• To monitor the developments in domestic energy efficiency and retrofit technologies and encourage trial pilot schemes
board
where appropriate.
• To create the photo library of front elevations and develop the Greater Manchester Retrofit Housing Web Portal and
Database to allow users to access the archetypes and measures packages as well as measuring progress towards the
emissions reduction targets.
Low Carbon Housing Retrofit
Sector
7
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1. Developing a Retrofit Standard for Existing
Housing Stock in Greater Manchester
Background: the Greater Manchester context.
A coordinated approach to improving existing housing stock is being developed and Greater Manchester’s Low
Carbon Economic Area (LCEA) designation presents an opportunity to introduce a common standards framework
for all domestic retrofit works throughout the conurbation.
Low Carbon Housing Retrofit
8
This report has been prepared by the LCEA
Housing Retrofit Standards Group, which
reports to the Low Carbon Housing Retrofit
Sub-Group of the LCEA Board and to the
Association of Greater Manchester
Authorities’ (AGMA) Environment
Commission. Understanding the local
housing stock will play a vital part in the
success of the forthcoming basic energy
efficiency measures programme, ‘Get me
Toasty’, which seeks to treat 75%
(approximately 400,000) of under-insulated
lofts or un-insulated cavities by 2013 in
Greater Manchester. This work provides a
valuable opportunity to identify the total
retrofit potential for the range of existing
domestic properties, many of which were
built before the new building regulations
came into force, it will also ensure that the
measures that are installed achieve their full
energy saving potential. It will also be crucial
when work is being planned that
householders are given the opportunity to
understand how to benefit from specifying
and installing higher standards of insulation
and energy efficient technologies, and at the
same time being encouraged to think
differently about their energy use to reduce
demand.
5
Retrofit Strategy 2011 and Energy Saving Trust’s
HEED database 2010
However, the longer-term ambition is to
engage with the whole of the existing
housing stock in order to reach the very
ambitious national carbon emission reduction
targets for 2020 and 2050. There are a total
of 1.1 million homes in Greater Manchester,
the majority (38%) of which consist of semidetached properties, followed by terraced
(33%), flats or maisonettes (15%) and
detached (14%) properties. Within this stock
it is estimated that 25% of the stock is of
solid wall construction and that there are still
over 500,000 untreated lofts and cavity walls
across Greater Manchester5. The Retrofit
Strategy proposes a GM wide network of
local showhomes and streets in every
neighbourhood, where the notion of ‘seeing
is believing’ will inspire take up of the Green
Deal.
How energy efficient
is your home?
26%
Loft Insulation
Fit loft insulation and save
around £110 and around
1 tonne of CO2 pa
Loft
26% of heat lost from an uninsulated home is
through the roof. Fitting sufficient loft insulation
is one of the easiest and most cost effective ways
of saving energy and money.
Hot water tank
Fit an insulating jacket
around the hot water tank
and save £20 and 160kg
of CO2 pa
Shower
Thermostat
Turn down the
thermostat by 1˚C and
save nearly £40 and
around 325kg of CO2 pa
Have a shower instead
of a bath and use
nearly two thirds less
water and energy
Fill gaps in floors
Fill in gaps in floors and
skirting and save around
£15 and around 130kg
of CO2 pa
Windows
Nearly a fifth of heat lost from an
uninsulated home can be through
windows. Double glazing can save
around £90 and 700kg CO2 pa.
18%
Boiler
Appliances
Upgrade to a condensing
boiler and save a third on
your heating bills and
around 875kg of CO2 pa
Turn TVs and other
appliances off
standby when not
in use
33%
Walls
Walls leak more heat than any other part
of the home – around a third in an
uninsulated home. If your home has cavity
walls, insulating them is the best way you
can save energy and money.
ESR fridge freezer
Upgrading to an Energy
Saving Recommended
one can save up to £37
and 150kg of CO2 pa
Draught proofing
Washing
Wash clothes at 30˚C rather than
at higher temperatures and use
a third less electricity, and so
produces a third less CO2
Draught proof windows and
doors and save £20 and
around 155kg of CO2 pa
Energy saving lightbulb
One energy saving lightbulb
will save £7 and around 45kg
of CO2 pa
11%
Doors and Floors
Gaps around doors and floors account for
around 11% of heat loss in an uninsulated
home. Sealing up gaps will stop heat
escaping.
Cavity wall insulation
Insulate cavity walls and save
around £90 and around
750kg of CO2 pa
Energy Saving Recommended
For the most energy efficient products, always look for the
Energy Saving Recommended logo.
For more independent and impartial advice on energy saving in the home
call 0800 512 012 or visit www.energysavingtrust.org.uk
© Energy Saving Trust 2007. E&OE
KEY
Grants and advice
available through
Energy Saving Trust
No-cost
or low-cost
measures
131263_City-South_Manchester_v5__ 19/03/2012 12:01 Page 9
The Group’s initial starting point has been to
identify the most common housing types
found within Greater Manchester. Then to
apply an archetype grouping across three
bands, against which the properties can be
categorised. Against each archetype a brief
description of the original construction details
that are common to the age and materials
used for that period has been given. It is
recognised that subsequent individual
improvements may have been carried out
either through planned investment or by
individual homeowners. Therefore, it will be
necessary for all users to have their dwelling
initially surveyed and assessed to establish
the actual energy rating. The archetype list
and measures set out in this report will assist
the user to decide where their property
currently falls with regard to the
recommended measures described within
these retrofit proposals.
The initial physical upgrade of a property to
improve energy performance will provide
significantly enhanced thermal and financial
benefits when combined with the behavioural
changes described in another key Low
Carbon Housing Retrofit report ‘The Missing
Quarter’6.
It is crucial that all retrofit schemes across
Greater Manchester are complemented by
awareness and behaviour change
programmes to ensure that occupants of the
improved properties understand and take full
advantage of the upgrades made to their
homes.
Green Deal Guidance
The Government’s Green Deal scheme aims
to enable households to install home energy
measures that are in part funded by a loan
attached to the property rather than the
household and repaid from savings in energy
bills. The scheme has been driven by the
need for a national comprehensive retrofit
programme and carbon emission targets set
for 2020 and 2050. In addition to its core
aims, the Green Deal provides the potential
to unlock not only a huge economic
opportunity, but social benefits through
warmer homes and mitigation of rising fuel
Missing Quarter report: http://manchesterismyplanet.com/behavioural-change
6
costs, it also raises the prospect of local
action where residents act together to bring
about improvements to their homes and
communities.
In 2011, Greater Manchester was chosen by
Government to trail-blaze a pilot for the
Green Deal scheme within social housing
ahead of its nationwide launch. GM has a
social housing stock of over 260,000
properties and of these up to 25,000 fall in
the ‘hard to treat’ category. The trailblazer
will seek to establish delivery partnerships
and supply chains to build customer
confidence in the Green Deal. It will be
essential that long term behaviour change
support for householders is intrinsic to the
Green Deal approach in order to achieve the
best possible savings. The success of the
Green Deal relies on the application of the
‘Golden Rule’ where customer repayments
are always lower than the savings made
though the energy efficiency works. The
Golden Rule calculations will be based on
assumptions and modelling. In its practical
application it is critical that households adopt
behaviour that will maximise the benefits of
the physical measure to ensure that the
anticipated savings are made.
Low Carbon Housing Retrofit
In July 2010 a stakeholder engagement
seminar was held to assess the need for a
Greater Manchester Retrofit Standard in
response to local and national developments.
From this the LCEA Retrofit Standards Group
was formed and tasked with the
development of this standard, through the
identification of property types, measures
and the options for the potential
improvement in energy performance of a
dwelling. The range of measures identified
has been developed to apply across the
majority of property archetypes.
Many other factors such as location,
conservation status, occupation etc will
affect the identified measures
recommended. These factors are discussed
in the GM Retrofit Strategy and the GM
Green Deal Intelligence report which will be
published in the near future.
Image by kind permission of Energy Saving Trust
The Challenge for the Retrofit
Standards Group
9
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A full discussion of the Green Deal
requirements and data intelligence is
included in the GM Green Deal Intelligence
report which will be published in the near
future.
Green Deal Criteria7:
Low Carbon Housing Retrofit
10
The first is called the “Golden Rule”; it states
that the measures recommended must
produce sufficient savings on the annual
energy bill to pay back the initial cost of
carrying out the works.
• The identified measures must be approved
so that the claimed bill savings can be
those accredited to pay back the loan.
• The provider of the loan must give
appropriate advice under the terms of the
Consumer Credit Act, under which the
individual’s circumstances shall be taken
into account.
• The loan stays with the property not the
individual, so is paid back as part of the
future energy bills.
• The present energy provider must be
informed of the proposed measures before
the funds are released to undertake the
works.
• The measures recommended should be
identified by an accredited Domestic
Energy Assessor “DEA” who has
undertaken an Energy Performance
Certificate on the property, or be based on
the recommendations contained within an
existing Energy Performance Certificate
which has been lodged by a DEA.
An objective adviser can be used, if
appropriate.
• The loan must be paid back before the
measures undertaken have reached
their replacement date, this can be up to
25 years.
• Only accredited installers/contractors will
be allowed to undertake the recommended
measures, or installations, for the funds to
be released under the Green Deal offer.
• Any Green Deal provider must have
consent from all relevant parties, including
the express consent of the current energy
bill-payer.
• Properties should have the basic energy
efficiency measures undertaken prior to
implementing the high tech solutions for
maximising energy income.
• The presence of a Green Deal charge must
be properly disclosed to all future
occupants whether through selling or
offering the property for rent.
Department of Energy and Climate Change: http://www.decc.gov.uk/
Energy Saving Trust: http://www.energysavingtrust.org.uk/
7
• There is a move at Government level to
look at how micro-generation income can
subsidise retrofit.
These measures have been put in place to
protect residents and will ensure that only
works appropriate to reducing the property’s
overall energy demands will be approved
under the Green Deal.
The GM Housing Retrofit strategy is being
developed in advance of the launch of the
Green Deal will support this by identifying the
most effective and appropriate combinations
of measures, assembled into packages, for
the different property types. The level of
retrofit activity is being monitored by proactive information gathering across the
region regarding the property types and the
measures installed in them over time, which
in turn will enable the retrofit packages to be
updated and refined.
Image by kind permission of Energy Saving Trust
Under the current proposals for Green Deal
the Government has set certain criteria which
must be met in order for the finance to be
made available, which protects the resident
from committing themselves to undertaking
uneconomic measures within their homes.
These criteria are subject to confirmation by
the end of 2011. Further information will also
be made available regarding the role of
social housing providers and the criteria for
social housing tenants in relation to the
Green Deal.
Retrofit Finance models:
Potential financial savings from retrofit installed measures
As well as the Green Deal a new Energy
Company Obligation (ECO) fund is under
development which will be a replacement to
the existing Carbon Emissions Reduction
Target (CERT) and Community Energy Saving
Programme (CESP) funds. A range of other
retrofit funding is available for renewable
technologies such as the Feed in Tariff (FiT)
and Renewable Heat Incentive (RHI). It is the
intention that all appropriate retrofit funding
should be maximised across Greater
Manchester and that all schemes should be
encouraged to meet the common standard
and framework proposed in this report.
Residents can achieve substantial savings on their annual energy bills by
installing a range of measures, some of which are shown below:
In addition to national funding programmes,
Greater Manchester has developed the local
‘Get me Toasty’ insulation scheme which
provides free cavity wall and loft insulation to
the majority of private sector households,
subject to survey. This programme aims to
install 400,000 basic measures by 2013.
Indicative Measures (figures for 2010)
Approx savings Payback time
(£/year)8
(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
Low Carbon Housing Retrofit
Image courtesy of Creative Concern
131263_City-South_Manchester_v5__ 19/03/2012 12:01 Page 11
Heat Recovery from Air (MVHR)
75
46 – 60
11
PVCu insulated Doors
15
50 – 57
The above table sets out estimated potential
savings for introducing these measures
within the home (based on a 3 bed semi
detached house). It should be noted that
savings cannot be simply added together
where multiple measures are being installed,
because the savings from measures are
interdependent. Individuals should be mindful
that the performance of the actual measures
as noted in the table above will be subject to
a range of factors such as the size of
property, occupancy and individual
preference for heating their property.
The savings shown have been developed
8
These figures are based on the Department for Energy and Climate Change (DECC), Building Research Establishment (BRE) and the Energy
Saving 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)
These payback periods are based on 2010 fuel prices and are likely to become shorter as fuel prices increase
9
from work done by the Energy Saving Trust
(EST) and Building Research Establishment
(BRE) along with other material used within
this report.
Further information on a wide range of
energy efficiency work and advice is
available through accessing their web sites
shown below:
www.energysavingtrust.gov.uk
www.bre.co.uk
131263_City-South_Manchester_v5__ 19/03/2012 12:01 Page 12
Aims of the report
It is intended that this report will enable all
users, from individual householders to large
scale landlords and those involved in
planning and installing retrofit measures, to
understand the potential range of energy
efficiency measures that may be fitted to
their properties and the most efficient order
in which to install them. In addition to
applying the basic and intermediate
measures the user’s opportunity for saving
money by reducing their ongoing energy
usage is highlighted. These
recommendations and packages of
measures are linked to the local 2020
Greater Manchester Climate Change Strategy
emissions saving target of 48%, and the
national targets of 34% by 2020 and 80%
by 2050.
12
Image from ‘The Missing Quarter’
Low Carbon Housing Retrofit
This work has been undertaken through the
Low Carbon Economic Area Domestic
Retrofit programme in order to offer
recommendations and advice on the
potential of energy efficiency measures that
can benefit all the properties within the
Greater Manchester area. The main
archetypes and their recommended
measures are described in this report to
assist users in identifying the present
condition and likely energy efficiency of their
properties and the potential improvements
and savings which can be achieved by
investing in the recommended measures.
The principle objective is to provide clear
realistic targets for typical property types
within Greater Manchester and a range of
clear, simple and increasingly cost effective
retrofit package options for our residents,
landlords, developers and installers, by
bringing together a range of services that will
ensure they receive the best advice and
support.
Creating these local archetype standards and
retrofit package options for 2020 and 2050
will meet the challenges set out in the LCEA
Low Carbon Housing Retrofit Strategy.
It is anticipated that Greater Manchester will
provide a lead both locally and nationally in
driving down the levels of domestic
emissions in line with or ahead of the
national timescales.
Decision Making
As well as the physical retrofitting
information in this report a range of further
support and advice is available from the
wider AGMA domestic retrofit programme
work being undertaken. It is intended that
users will be able to access the following:
• Guidance on how to best ensure that
behavioural change programmes are
effective and properly integrated into
retrofit projects as described in the
‘Missing Quarter’ report.
• Obtain objective advice on retrofit
standards and appropriate measures to be
undertaken as described in this report and
in the Retrofit Strategy.
• Support through Greater Manchester’s
approach to Green Deal:
• AGMA is working towards creating the
most appropriate delivery programme
for Green Deal for the conurbation
through the establishment of a Greater
Manchester Green Deal
partnership/framework designed to give
confidence to consumers and strategic
direction to activity. This approach will
provide access to:
• An independent, impartial and expert
customer advice service that can
support the customer journey and
promote most appropriate retrofit
project approaches.
• Accredited suppliers whose materials
and performance meets the required
specifications and standards.
• Accredited installers/contractors
whose operatives are appropriately
trained to undertake these works and
installations within the home.
• The best market prices for
guaranteeing both materials and
workmanship.
• Installers/contractors who can if
needed provide servicing and
maintenance support, if called upon.
• Guarantees that will be honoured by
both suppliers and installers.
131263_City-South_Manchester_v5__ 19/03/2012 12:01 Page 13
Potential Low Carbon Economic
and Social Benefits
Our aim is to put every representative home
type in the area on a database accessible
through a web portal, so it can be assessed
against this GM Housing Retrofit Standard, to
highlight the most cost and energy efficiency
interventions based on property type and
other stock intelligence. This database will
also allow forward planning of any retrofitting
work so that when homes change hands
future householders or managers will be able
to pick up where the previous ones left off.
A core ‘grid’ of 9 principle types of properties
and approximately 24 types of interventions
have been identified and developed into
retrofit option packages linked to the national
2020 and 2050 emissions reduction targets.
This will enable adoption of these standard
packages as a Greater Manchester core
programme of improvements to homes,
providing the AGMA ‘family’ of organisations
with a common framework within which to
maximise a range of low carbon economic
and social benefits including:
• Provision of business assistance to
Construction SMEs (small and medium
enterprises) located within the conurbation
to maximise the capacity of local firms to
bid for and undertake the works.
• Understanding of the range of
interventions that will help make best use
of local existing and potential sources of
Construction Products. This will help to
minimise the environmental impact during
the manufacturing and transporting
stages, and to maximise the local
economic impact and its multiplier effects.
• The option packages will hopefully enable
the supply chain to develop with more
confidence about the future and the
capacity needed.
• Greater Manchester’s wide sharing of best
practice and intelligence on the regional
supplier base will enable these packages
to be updated and remain relevant.
• Working with local colleges, and with area
teams focussed on assisting NEET (not in
employment, education or training) young
people to provide additional incentives to
develop and join Construction Courses for
successful sandwich placements and
improved job prospects.
• Providing a focus on ‘entry level’
construction work opportunities particularly
for families with complex needs and with
inter-generational unemployment, as a
supported package with college and
mentoring.
• Developing an understanding of
households in fuel poverty (see below) and
using this to inform the strand of the
forthcoming Green Deal programme which
will allow for the PAYS (pay as you save)
principle to be subsidised by public funds.
• To place this framework of specific
interventions in the public domain, with the
stability of commitment from across the
range of Greater Manchester
organisations, as a resource to other
private sector investors in the Domestic
Refurbishment market, including ‘green
mortgage’ providers and other substantial
fund holders and investors.
The opportunities to realise the economic
potential of the Green Deal in Greater
Manchester are further discussed in the GM
Housing Retrofit Strategy.
Fuel Poverty.
The existing Government’s definition of fuel
poverty is when a household spends 10% or
more of its income on fuel costs; however a
new definition is under development. Fuel
poverty is an issue that disproportionately
affects households on low incomes and can
severely impact on the health and wellbeing
of vulnerable households, and in particular
the elderly. Improving the energy efficiency of
properties will assist greatly in minimising
the health and financial impacts of fuel
poverty.
Certain national funding streams have been
available to target Fuel Poverty, with the new
Energy Company Obligation (ECO) due to
replace the existing Community Energy
Saving Programme (CESP) next year.
Low Carbon Housing Retrofit
It is expected that residents, landlords and
owners who wish to consider the Green Deal
offer for their property will find this suite of
advice and guidance helpful. It is further
hoped that the user will decide to use The
Greater Manchester Green Deal Partnership
network of selected independent and
objective advisors to support accessing the
Green Deal and other funding options,
administration of the works and procurement
of the recommended retrofit measures.
13
131263_City-South_Manchester_v5__ 19/03/2012 12:01 Page 14
Energy Performance Certificate10
The principle tool for assessing a dwelling’s
energy efficiency performance is the
Standard Assessment Procedure “SAP”
which categorises the dwelling using seven
band ratings from “A”, the best performing,
to “G”, the worst performing, and is normally
displayed on an issued Energy Performance
Certificate (EPC).
The title for this document is ‘Transforming
homes from G to A’ based on this
improvement of energy efficiency SAP rating
which will be required from all domestic
properties to meet the GM national emissions
reduction targets. The Retrofit Strategy
indicates that to achieve the national
standards for 2050 across Greater
Manchester 90% of all homes will need to
achieve an average of band B.
The EPC certificates also show a variety of
useful information relating to a dwelling; from
its actual energy rating together with its
An Energy Performance Certificate display
showing the proposed improvements in SAP
banding is shown below.
If the dwelling has had an EPC assessment
undertaken to establish its SAP rating, as an
initial starting point for planning any retrofit
works the EPC certificate should be viewed
to evaluate the current status and review the
potential measures recommended for
improving the energy efficiency.
At the time of writing this report the
Government is currently looking at
introducing a new layout for the EPC
certificate, which will provide clearer advice
to the owner on what initiatives can be
undertaken to enhance their properties
overall energy performance and the savings
that would result.
Current
Potential
A
B
Diagram from GM Retrofit Strategy draft Source: DCLG
Low Carbon Housing Retrofit
14
potential rating should the owner take action
and invest in the recommended measures
listed in the accompanying report.
Summary
The opportunity provided by both the local
GM and national emissions reductions
targets and the development of funding
mechanisms such as the Green Deal, Energy
Company Obligation, FITs and RHI and local
‘Get me Toasty’ scheme has led to the
development of a range of work packages for
Low Carbon Housing Retrofitting. It is seen as
important and economically astute to
encourage all ten authorities and all
organisations in Greater Manchester to work
to a common framework of targets,
standards, methodologies and timeframes.
It is recognised that interventions through
works only will not address the behavioural
changes necessary to ensure that the
occupants achieve the full potential savings
on their energy bills and that advice and
support are therefore also key factors in
reducing emissions. It is recommended that
a Greater Manchester housing stock
database and web portal be developed to
keep track of improvement and to allow
owners to search for their house type and the
most effective measures packages.
90%
of stock
C
10%
of stock
D
GM
average
E
F
10
http://www.direct.gov.uk/en/HomeAndCommunity/BuyingAndSellingYourHome/
Energyperformancecertificates/index.htm
G
Proposed Greater Manchester
EPC Targets
131263_City-South_Manchester_v5__ 19/03/2012 12:01 Page 15
The journey of improving solid walls with insulation
During
After
Low Carbon Housing Retrofit
Before
15
Before
During
After
It’s not just about improving energy efficiency is it?
131263_City-South_Manchester_v5__ 19/03/2012 12:01 Page 16
2. Housing Retrofit potential in
Greater Manchester.
Property Archetypes
The initial approach taken by the Retrofit Standards Group has been to categorise the representative property types
throughout the GM area into set archetypes groupings. The 9 most common GM property types have been
identified. Archetypes 1 to 8 represent over 95% of the housing stock11, less common, non traditional property types
have been put together in Archetype 9. This approach ensures that the original construction standards for each
type are accounted for and appropriate to the retrofit package options being recommended.
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
Identification of Property Types
Low Carbon Housing Retrofit
16
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 GM
area as possible. The aim is to establish a web portal where you will be able to view this library by accessing a Greater Manchester Low
Carbon 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:
Archetype 1 pre 1919
Typical property: ‘Victorian’ 2 storey pre
1919 mid terraced house, brick built with
225 mm walls and a slate roof.
Includes: All solid wall construction mid
terraced housing including ‘finger cavity’
stock brick walls, and larger 340 mm solid
walls. As a general rule, this would include
all terraced property built before 1919.
Archetype 2 pre 1919
Typical property: ‘Victorian’ 2 storey pre
1919 ‘end of’ terraced house or small
semi-detached, brick built with 225 mm
walls and a slate roof.
Includes: All solid wall construction end of
terrace/semi – detached housing, including
‘finger cavity’ stock brick walls, and larger
340 mm solid walls. As a general rule,
this would include all semi- detached/end
terraced property built before 1919.
Archetype 3 pre 1919
Typical property: Large
‘Victorian’/’Edwardian’ detached house,
brick built with 225 mm or 340 mm walls.
Includes: All solid wall construction
detached housing, including ‘finger cavity’
stock brick walls, and larger 340 mm solid
walls. As a general rule, this would include
all detached property built before 1919.
http://data.gov.uk/dataset/english_house_condition_survey
11
131263_City-South_Manchester_v5__ 19/03/2012 12:01 Page 17
Archetype 5 pre 1961
Archetype 6 1937
Typical property: Converted Large
‘Victorian’/’Edwardian’ house, brick built
with 225 mm or 340 mm walls.
Typical property: 1960’s ‘town house’
with 275 mm cavity walls.
Typical property: 1930’s ‘inter war’ semi
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, this
would include all mid terraced properties
built from 1920 up to 2000.
Includes: All cavity wall properties,
including properties with partial cladding,
and tile hung bays. As a general rule, this
would include all semi detached/end
terraced properties built from 1920 up to
2000.
Includes: All flats in buildings of solid wall
construction individually evaluated.
Low Carbon Housing Retrofit
Archetype 4 pre 1919
17
Archetype 7 1930
Archetype 8 pre 1955
Archetype 9, 9a, & 9b 1974
Typical property: 1930’s ‘inter war’
detached house with 275 mm cavity walls.
Typical property: 1950’s ‘low rise’ brick
built flats, with 275 mm cavity walls.
Typical property: 1960’s ‘non traditional’
low rise construction.
Includes: All cavity wall properties,
including properties with partial cladding,
and tile hung bays. As a general rule, this
would include all detached properties built
from 1920 up to 2000.
Includes: All cavity wall properties,
including properties with partial cladding,
and tile hung bays. As a general rule, this
would include all low rise brick built flats
constructed from 1920 up to 2000.
Includes: All non traditional construction,
including ‘system built’ properties such as
Wimpey ‘no-fines’ Reema hollow panel,
high rise concrete frame flats, and timber
framed housing.
Archetype 9c
Typical property: Medium and High rise
flats
131263_City-South_Manchester_v5__ 19/03/2012 12:01 Page 18
Options for Improvement through Identified Measures
For each property archetype three approaches have been identified depending on the extent and standard to which the
properties 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 new
technology) (2050 Standard)
After Major Measures
2050* SAP/EPC Band
/kgCO2/m2
Archetype 1
SAP 1 band G CO2 1
<1900 mid/terraced house with
solid wall
SAP 57 band D CO2 46
SAP 66 band D CO2 61
SAP 87 band B CO2 84
Archetype 2
SAP 1 band G CO2 1
<1900 end/terraced house with
solid wall
SAP 55 band D CO2 49
SAP 64 band D CO2 59
SAP 83 band B CO2 80
Archetype 3
<1900 large detached house
with 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 4
Converted 1900-29 large
detached 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 5
SAP 48 band E CO2 43
1960 mid terraced house with
cavity walls including those with
tile hung bays
SAP 64 band D CO2 60
SAP 72 band C CO2 70
SAP 88 band B CO2 86
Archetype 6
SAP 1 band G CO2 1
1930 Semi detached house with
cavity walls including those with
tile hung bays
SAP 61 band D CO2 55
SAP 72 band C CO2 68
SAP 85 band B CO2 82
Archetype 7
SAP 1 band G CO2 1
1930 detached house with
cavity walls including those with
tile hung bays
SAP 56 band D CO2 50
SAP 69 band C CO2 64
SAP 82 band B CO2 78
Archetype 8
1950 low rise cavity brick built
flats
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, & 9c
SAP 53 band E CO2 49
1960 system built mid/terraced
wimpy no-fines etc
SAP 63 band D CO2 57
SAP 71 band C CO2 67
SAP 85 band B CO2 81
*All figures use NHER Stock
Assessor calculations
Low Carbon Housing Retrofit
The table below shows the “as built” SAP
rating and related EPC band for each
archetype. It shows the level of improvement
that each requires to meet the 3 standards.
After Basic Measures* After intermediate
Measures 2020*
SAP/EPC Band
SAP/EPC Band
/kgCO2/m2
/kgCO2/m2
Type
18
Basic and intermediate measures, as their
name implies will not be sufficient to meet
the national 2050 target meaning that the
properties will have to be retrofitted at least
once more before then.
As Built* SAP/EPC
Band /kgCO2/m2
131263_City-South_Manchester_v5__ 19/03/2012 12:01 Page 19
It is apparent from the above table that
especially with the older stock; it may not be
possible to achieve the set standards by
2020 without major investment being made.
The three recommended Basic, Intermediate
and Major Standards measures identified
when implemented will impact on
SAP/EPC/kg CO2 levels. They have been
broken down into sub group elements to help
users decide where their property is in
relation to the works being recommended.
This will also help to identify whether the
investment will be cost effective in the longterm and help to reduce the user’s potential
future energy costs.
Specifications for these retrofit package
options can be found in Technical
Appendix A.
This sectional view of a property shows what
can be done in order to enhance the energy
efficiency of a property. Specific details for
these elements are listed within each of the
Basic, Intermediate and Major retrofit
options packages. It is important to realise
that not all the work is likely to be carried
out at one time, but will be best
undertaken when a natural ‘trigger point’ is
reached eg when work is being carried out
such as new kitchen/bathroom or roof or
when 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
Low Carbon Housing Retrofit
Users will also need to consider when this
investment is to be made on a property and
how best it will contribute to the 2050
targets. These aim to reduce the average
home’s CO2 emissions from 6 tonnes down
to only 1.5 tonnes per year, to meet the
overall 80% reduction targets set by the
Government for 2050.
Retrofit potential property
overview
G Hardboard laid over floors & sealed
skirting boards to prevent drafts
19
H External walls, see treatment potential
in the Technical Appendix
I Insulated door and frame fitted
J Voltage optimisation meter fitted to
electric distribution board
K Timber floor overlaid with hardboard &
sealed skirting boards to stop drafts
L Insulation fitted externally to prevent
cold bridge
M Solid floor renewed with insulation
layer installed
N External garden used for ground
source heat recovery or alternative
use air source heat recovery units
Diagram courtesy of City South Manchester Housing Trust
The NHER Assessor software used to develop
these target standards is based on reduced
SAP (RD SAP) which relies on approximations
and assumptions. Calculations carried out
using full SAP methodology may therefore be
different and are likely to be more accurate.
131263_City-South_Manchester_v5__ 19/03/2012 12:01 Page 20
Basic Measures
These works will improve
the energy efficiency of
the properties and reduce
energy usage and the
expenditure on fuel bills
and should be considered
as a minimum first stage
for retrofitting.
Although not part of the building
fabric, installation of energy
efficient ‘A’ rated appliances
should also be an intrinsic part
of any basic retrofit project.
Reduced
infiltration
Loft
Insulation
Cavity
wall
insulation
Reduced
flow hot
water
fittings
Primary
pipework
insulation
Thermostatic
radiator valves
Energy
saving
light
bulbs
Draught
proofing
Diagram courtesy of EST
Low Carbon Housing Retrofit
20
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 around
service 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 separate
channels for heating and hot water; a cylinder thermostat; TRVs.
Low Energy Lighting
Install 100% low energy lighting
131263_City-South_Manchester_v5__ 19/03/2012 12:01 Page 21
Intermediate Measures
linked 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 and
cost efficiency for each measure.
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 cavity
width and materials. Target U-value ~ 0.2W/m2K.
Cavity fill and external insulation. Performance dependent on cavity
width 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. Performance
dependant 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 energy
extract fans
Heating Systems/Controls
Upgrade gas boilers to “A” rated condensing incorporating a flue
gas heat recovery unit and high efficiency hot water system.
Controls - as for Basic Measures and use of a weather and/or load
compensator
Low Carbon Housing Retrofit
Pitched Roofs
21
131263_City-South_Manchester_v5__ 19/03/2012 12:01 Page 22
Solar water
heating
Solar
Photovoltaic
Major Measures
(Including new
technology) – linked
to 80% 2050 national
emissions targets.
While these measures can
be more expensive or
disruptive, the possibilities
of revenue generation from
some of these measures
will mean that in some
circumstance they should
be considered earlier.
Loft
insulation
High
performance
insulated
DHW cylinder
Triple
Glazing
Reduced/
Sensor flow
hot water
fittings
Reduced
infiltration
Air source
heat pumps,
(or ground
source heat
pumps in
larger
properties)
Primary
pipework
insulation
External wall
insulation
Energy saving
light bulbs
Thermostatic
radiator valves
Draught proofing
Diagram courtesy of EST
22
Low Carbon Housing Retrofit
Cavity wall
insulation
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 recovery
minimum 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
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 to
maximise the opportunities under the different funding models such as the Green Deal and local Get me Toasty scheme.
131263_City-South_Manchester_v5__ 19/03/2012 12:01 Page 23
Summary
Analysis of the potential for thermal
efficiency improvements across the GM
housing stock has identified the following:
• Nine specific archetypes have been
identified as the most prevalent across
the Greater Manchester housing stock.
• These standard levels have been
designed to match the national 2020 and
2050 emissions reductions targets.
• Basic, Intermediate and Major Packages
of measures have been identified for each
archetype as it was originally built.
It is recognised that property owners are
unlikely to undertake a full retrofit of the
property at the same time. This document
will help to ensure that an incremental
‘whole house’ approach is as efficient and
cost effective as possible.
Low Carbon Housing Retrofit
Based on the range of 9 archetypes
described on page 18, using the as built
wall specifications for the period of
construction, a range of wall treatments
have been shown in Technical Appendix B.
The measures described in the table enable
the user to assess the impact of the basic
and intermediate treatment measures on
the walls U-values once installed. These are
not by any means exhaustive and in the
short to medium term advice should be
sought from appropriate design
professionals before selecting the optimal
solution for a given situation. As the GM
stock intelligence data is built up a greater
body of evidence of what works in these
situations will be available. Eventually users
will be able to select solutions from this
stock intelligence database via the web
portal discussed earlier.
• Target standards for SAP level linked to
EPC band and kgCO2/m2 are then defined
for three levels of retrofit intervention –
Basic, Intermediate and Major.
23
Image by kind permission of Energy Saving Trust
Wall Types and Appropriate
Treatment
131263_City-South_Manchester_v5__ 19/03/2012 12:01 Page 24
3. Specific Considerations
Building Regulations and Planning
A further consideration for the designer and/or property owner, when looking at any treatment to external walls, is
to take into account the impact the proposed treatment on the existing structure and whether it will meet current
Building Regulation requirements.
As a rule of thumb, if the treatment covers
more than 25% of the wall area then
Building Regulation requirements will apply;
if in doubt check with your local Building
Control Officer, prior to applying any
treatment.
Low Carbon Housing Retrofit
24
Whilst our attention in this report is focused
primarily on wall treatments, this rule of
thumb applies equally to the upgrading of
other ‘retained thermal elements’ such as
floors and roofs.
Improvement works affected by Building
Regulation control include replacement
windows, external doors with more than 50%
glazing, installation of central heating boilers
and/or wood burning stoves,
new/replacement electrical wiring, and the
installation of renewable technologies.
Building Regulation requirements are broken
down in two parts, procedural and
substantive. The procedural requirements in
this instance would be to either use
accredited contractors registered on a
nationally recognised ‘Competent Persons
Scheme - thus allowing them to self certify
that their works comply, or to seek approval
directly from a Building Control body. The
substantive element is simply a matter of
ensuring that the treatment works meet the
functional requirements of Part L of the
Building Regulations, details of which are
outlined in the supporting guidance that is
Approved Document L1B.
It should be noted that where approval under
Building Regulations becomes necessary,
charges will be applicable for determining
compliance, unless the work is undertaken
under the auspices of a ‘Competent Persons
Scheme’.
The on-going intelligence gathering of
improved Greater Manchester properties will
not only assist those carrying out the work,
the pattern book approach that it will develop
will also assist Building Control. As they will
not only be able to contribute to this body of
evidence it will also prove invaluable in
assessing applications to ensure that as the
pace of retrofit picks up it will not be held up
by the statutory procedures.
Planning permission may also be required,
particularly for measures that would involve
changes to the external appearance of the
property. Advice should be sought from the
local authority.
Risk From Flood Damage
The environmental impact of the risk of
flooding is an important consideration when
considering any treatment to cavity walls.
Flood risk levels for a property can be found
at 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 map
and
• enter your “post code” where you will find
clear guidance on the likelihood of flooding
damage to your property and in the local
area in general.
131263_City-South_Manchester_v5__ 19/03/2012 12:01 Page 25
Risk from Fire
In England all External Wall Insulation
systems must meet the requirements of the
Building Regulations approved documents B1
(Fire Safety - dwellings) Section B4 (8). This
document can be found at the following link:
http://www.planningportal.gov.uk/uploads/br/
BR_PDF_ADB1_2006.pdf
http://www.inca-ltd.org.uk/pdfs/INCATechnical-Guide-01-Fire-PR-for-EWISystems.pdf
Photo courtesy of Property Tectonics
The Greater Manchester Get me Toasty
campaign, which promotes Loft and Cavity
Wall Insulation to private householders,
should identify flood risk properties as part of
its delivery process and recommend suitable
materials for the affected properties.
Further guidance and material specifications
is offered by the Insulated Render and
Cladding Association (INCA):
Interstitial and Surface
Condensation
Condensation is a modern phenomenon
affecting approximately 15% of homes in the
UK (BS 5250) and its effect is generally
greater in post-war housing. Condensation
must not be confused with dampness due to
water penetration from the outside or
dampness caused by the normal drying out
of a new building. Condensation, like all
forms of dampness, is a particular problem
because damp homes are ‘harder to heat.’
Surface condensation can occur when water
vapour, usually from occupants and their
activities condenses on an exposed surface
or interstitial condensation where it is within
the fabric.
Air containing a large amount of water vapour
has a higher vapour pressure than drier air
and therefore moisture from the wetter air
disperses towards drier air. This means that
the concentration of moist air in a kitchen or
bathroom easily disperses throughout a
dwelling and the moist air at higher pressure
inside a dwelling tries to escape by ventilation
and through the structure where it may
condense within it.
Air at all temperatures absorbs moisture and
the higher the temperature is the more
moisture it can contain. This air will reach a
state when it cannot absorb any more and it
will have therefore have reached saturation
point. Condensation will occur when the
warm moist air is cooled to its ‘dewpoint’
temperature, either by being brought into
contact with cold surfaces or by passing into
a cooler part of the building.
Condensation will also occur on absorbent
surfaces but will not always show until the
surface is very damp. In these cases mould
growth can occur consisting of black patches
which will cause deterioration of decorative
finishings and potentially health problems for
residents. This type of growth can also form
on clothing and shoes etc. stored in
unventilated and un-heated built in
cupboards.
Low Carbon Housing Retrofit
A range of materials are available for
insulating cavity and solid walled properties.
Some are more suitable than others in areas
of high flood risk, for example; blown mineral
fibre filled cavities, if affected by flood water
will need to have the fibre removed to enable
the drying out process to occur. Properties
that are situated in flood risk areas should be
insulated with alternative materials such as
bonded EPS beads which drain freely or
injected PUR expanding insulation which can
assist in providing an effective water barrier
as an integral part of the existing wall
construction. Guidance from the product
manufacturer should be sought prior to
installation and consideration given to the
breathability of the resulting wall.
25
131263_City-South_Manchester_v5__ 19/03/2012 12:01 Page 26
The occurrence of condensation is influenced
by a number of factors:
1. The number of occupants and their
behaviour;
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 remains
unheated;
6. Level of insulation and airtightness;
7. Amount of ventilation and
Low Carbon Housing Retrofit
26
8. Prevailing weather conditions.
To reduce the risk of condensation attention
should be given to improving ventilation,
insulation or heating, or a combination of
them.
Checklist of considerations:
• Check that condensation is the cause of
the dampness problem.
• Improve insulation or its continuity
particularly if mould growth is associated
with cold bridges e.g. uninsulated lintels.
This is obviously more expensive than
ventilation but the main aims are to keep
surface temperatures above dew point.
This measure is linked to heating as
insulation without a suitable heat input will
not provide a satisfactory remedy.
Double glazing windows will reduce the
occurrence 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
Diagram courtesy of EST
When a property is retrofitted to make it
more energy efficient, by improving air
tightness to prevent heat loss along with high
levels of wall insulation, there is a need to
consider the flow of moisture through and
out of the building. Adequate ventilation is
essential to ensure that condensation does
not become a problem either within the
building fabric (a) or within the rooms (b).
a. Moisture trapped and condensing within
the building roof or walls is known as
interstitial condensation and can cause
rot, mould and fungal growth.
Calculations should be carried out to
ensure that this does not happen. There
are some circumstances such as in stone
buildings and some solid wall properties
131263_City-South_Manchester_v5__ 19/03/2012 12:01 Page 27
where it is advantageous to the building
fabric for materials to be used that allow
moisture to pass through them.
The installation of the more expensive heat
recovery measures would generally only be
introduced into a property that has
undergone both the basic and intermediate
measures recommendations. A property
which has undergone such extensive works
can be affected by a restricted air flow which
may result in the property suffering from
internal condensation.
Design Considerations
1. Bath and shower use,
Low Carbon Housing Retrofit
b. Moisture and stale air from the activities
within the home will also need to be
removed both for comfort and for
minimisation of allergens such as dust
mites. With all the draughts removed this
level of ventilation will need to be
designed in. The greater the level of
insulation the more the ventilation
becomes a whole house solution. This can
be done using passive stack ie’ (no fans)
using the buoyancy of the warm air or by
Mechanical Ventilation with Heat Recovery
(MVHR) where a fan pushes the air
thorough a heat recovery unit.
Moisture in a home is produced principally
by:
2. Cooking or
3. Drying clothes indoors or
4. Running an unvented tumble dryer.
Residents may be tempted in these
situations to open doors or windows to allow
the moisture-laden air to escape, which will
also cause the property to lose heat. It is
recommended that the designer should
consider the replacement of ordinary fans
with the installation of new low voltage MVHR
extractor fans within the kitchen and
bathroom. Modern replacement fans have
been developed to recover up to 85% of the
heat loss during the extraction of the moist
air from the room and at the same time bring
in fresh air from the outside that is partially
heated during the heat exchange process.
An alternative would be a fully ducted
ventilation system throughout the property
either using a passive stack or with the unit
located in the loft area that would allow the
heat recovery to take place during the air
exchange process. This option would be
considerably more expensive.
27
Image by kind permission of Energy Saving Trust
Designers of retrofit works will be aware that
although the walls, roof and floor elements
are the primary consideration when looking
at energy efficiency, specific technical
determinants such as eaves details, integral
garages, extensions, rooms in the roof and
velux windows will all need to be considered
on a case by case basis.
It is hoped that this document will allow
retrofit designers and property owners to
adopt a sensible and cost effective
methodology for assessing the most
appropriate measures to install and the most
suitable order in which to undertake the work.
131263_City-South_Manchester_v5__ 19/03/2012 12:01 Page 28
28
Sustainability and the Home
Low Carbon Housing Retrofit
There is also a need to consider the effect of
installing insulation to an existing wall
structure when considering the general
specification and performance calculations
for the U-value. A before and after calculation
to establish the dew point should be carried
out by the designer to see if the insulation
will cause any interstitial condensation within
the existing materials. As noted above failure
to do so could lead to mould growth, rot and
fungi growth occurring within or on the
structure behind the newly installed
insulation material.
The Retrofit Standards and Housing
Intelligence Groups have taken the
opportunity to set out the full range of
measures which can be applied to provide a
sustainable living environment. The list
shown in Appendix A includes an extensive
review of measures that can have a
considerable impact on the following:
• Energy Usage
• Water Usage
household’s energy consumption, financial
expenditure and carbon footprint.
Users are recommended to read the ‘Missing
Quarter’ report which includes clear
guidance on ensuring that behaviour change
advice is included in any retrofit project or
programme. It is commonly recognised that
up to 25% of the annual cost of a typical
home’s energy bill can be saved by adopting
a different approach to energy use.
Technology Advancement
As with all advances in the field of energy
efficiency the current range of products in
the marketplace will have a varied impact on
reaching the design standards required.
Users need to be aware that, due to
restrictions on available space within the
home, it may not always be possible to
incorporate some products. As the
technology advances, and improvements are
made to the products performance and
overall size, such restrictions may be
overcome. New products will continue to
enter the market as the technology develops
through increased innovation. It is anticipated
that some of the older and harder to treat
stock will be able to reach the 2050 target of
an 80% reduction in their annual CO2
emissions, in a more cost effective and
affordable way as a result of such innovations.
This process will be streamlined at the Greater
Manchester wide level by developing and
using the stock intelligence database and web
portal noted earlier. This will allow
development and testing of new products, plus
the effective dissemination and use of best
practice information across the whole area.
Summary
This section will allow property owners and
retrofit programme designers to assess their
schemes against a range of specific issues
which will affect all or some of the Greater
Manchester housing stock.
The topics above are not designed as a
comprehensive list of issues but will provide
a useful check list of specific considerations
for any proposed works.
• Behavioural Change
• CO2 emissions.
Individual users should consider that in future
there will be ever increasing demands placed
on both energy and water supplies. While the
introduction of new technologies may help, it
is recognised that changing our behaviour
regarding how we use these scarce
resources will make significant savings to a
Image courtesy of C. Baker
Image by kind permission of Energy Saving Trust
131263_City-South_Manchester_v5__ 19/03/2012 12:01 Page 29
4. Conclusions
These will enable a Common Standard and
Framework of retrofit measures to be
adopted across all areas and organisations in
Greater Manchester, yielding substantial
financial savings and a pathway for achieving
the national carbon emissions targets in the
domestic housing retrofit sector.
1. With 1.1 million homes which are
producing more than a third of the CO2
emissions in Greater Manchester, the
developing Green Deal represents a
significant opportunity for householders
and landlords to improve the energy
efficiency of their properties. This will
contribute significantly towards the
recently adopted Greater Manchester
Climate Change Strategy target of
48% carbon emissions reduction by
2020, which exceeds the national
target of 34%.
2. A review of the housing stock has
identified 9 major archetypes of
properties to aid understanding of what
is required.
3. A potential for energy efficiency
improvement for each archetype to reach
the national carbon emissions reduction
targets of 34% by 2020 and 80% by
2050, has been identified in the form of
12
a SAP rating linked to an Energy
Performance Certificate and the
associated amount of carbon per meter
squared for that property type.
4. Each of these SAP target standards have
then been analysed and a suite of energy
efficiency measures designed
appropriate to each archetype, identified
as basic, intermediate (2020 target) and
major interventions (2050 target).
5. A full evaluation of the cost and energy
rating of each measure is included in the
Technical Appendices.
6. Crucially information is also included
indicating the most efficient and cost
effective order in which to install these
measures using natural trigger points
within the lifespan of the property and it’s
ownership. Examples of these trigger
points would include such works as a
new roof, new windows, kitchen/
bathroom upgrades or an extension.
Lifestyle changes are also recognised as
appropriate trigger points, including
moving home, increased or reduced
family size or occupancy.
7. It is recognised that property owners are
unlikely to undertake a full retrofit of the
property all at once; this document will
help to ensure that an incremental
‘whole house’ approach is as efficient
and cost effective as possible.
8. These levels of SAP/EPC/kg CO2 targets
give property owners the option to
upgrade the energy efficiency to the
highest level possible during planned
work to avoid potential wasteful and
costly revisiting of the same areas later
on when the higher levels are likely to be
required.
9. A range of specific building
considerations are discussed to ensure
users of this document are informed of
key issues that are important in any
retrofit planning.
10. It is made clear that in order to reach
these very stretching national targets for
2050 all the properties which already
exist in Greater Manchester will require
some form of retrofit to ensure they meet
the energy efficiency standards required
to achieve the 80% emissions savings.
11. Finally it is also acknowledged that some
of the SAP/EPC/kg CO2 targets
recommended will have to take
advantage of newly developing
technologies that may not be fully
available yet.
12. Development of a Greater Manchester
web portal and database of these
archetypes and retrofit solutions could
effectively be linked to the Building
Research Establishment (BRE) National
Refurbishment Centre12 and the National
Energy Efficiency Data-Framework
(NEED).13
www.rethinkingrefurbishment.com
http://www.decc.gov.uk/assets/decc/11/stats/energy/energy-efficiency/2078-need-data-framework-report.pdf
13
Low Carbon Housing Retrofit
The research and standards review
carried out for this report has led to
the following conclusions and
recommendations.
29
131263_City-South_Manchester_v5__ 19/03/2012 12:01 Page 30
5. Recommendations
Recommendations for this report were developed following the compilation of evidence by the GM Housing Retrofit
Standards Group and the associated stakeholder seminar held in July 2010. The recommendations should be
adopted to maximise the potential benefits of physical housing retrofit programmes and to endorse long term
energy efficiency changes in behaviour.
The following recommendations are made to inform those responsible for developing strategy and implementing domestic retrofit programmes
in both the private and social sector.
Sector
Recommendation
Social Landlords
• 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
maintenance budgets.
• To link these standards and targets to planned maintenance ‘trigger points’ such as kitchen/bathroom upgrades
or new windows etc, to ensure effective long term cost efficiencies.
Low Carbon Housing Retrofit
30
• Take into consideration the items included in the specific considerations section when planning or tendering a
project.
Local Authorities
• Local Authorities to recommend these SAP/EPC/kg CO2 standards to all social landlords, retrofit developers and
private householders through the Planning and Building Control services.
• To work with private landlords and Landlords Associations to promote the installation of measures to improve the
energy efficiency for the private rented stock. This will include promotion through the landlords forums, the Greater
Manchester Landlords 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 Green
Deal/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 Greater
Manchester.
• 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.
131263_City-South_Manchester_v5__ 19/03/2012 12:01 Page 31
Recommendation
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’, 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.
Low Carbon
Housing
Retrofit/LCEA
committee
• To carry out an annual review of this report in light of developments in retrofit technology and funding models such
as the Green Deal. This will ensure that this document remains relevant and provides appropriate recommended
standards up to 2020.
Large scale
Scheme
Developers/
Installers
• The Greater Manchester wide Toasty scheme should take flood risk factors into account prior to recommending
specific materials for CWI.
• To monitor the developments in domestic energy efficiency and retrofit technologies and encourage trial pilot
schemes where appropriate.
• To create the photo library of front elevations and develop the Greater Manchester Retrofit Housing Web Portal and
Database to allow users to access the archetypes and measures packages as well as measuring progress towards
the emissions reduction targets.
Low Carbon Housing Retrofit
Sector
31
131263_City-South_Manchester_v5__ 19/03/2012 12:01 Page 32
Greater Manchester Low Carbon Economic
Area Retrofit Standards
TECHNICAL 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
Low Carbon Housing Retrofit
32
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
140
m2
£10.00
£1,400.00
Option A - Loft top up insulation to minimum 270mm laid between ceiling
0.16W/m2K
rafters and on hatch to achieve set U-value
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
Lay hardboard covering over floor boards to prevent air leakage
Aim
6mm thick
Option A – Internal insulation - Dry lining of all external walls to achieve
minimum U-value
0.35W/m2k
80
m2
£45.00
£3,600.00
Option B – Internal insulation - Dry lining of all external walls to achieve
intermediate 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
131263_City-South_Manchester_v5__ 19/03/2012 12:01 Page 33
Sustainability and Energy Measures
Aim
Rate*
Cost*
70
m2
£35.00
£2,450.00
20
m
£70.00
£1,400.00
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 line
with 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
Option B - Take up ground floor boards and insulate between joists and
relay to achieve 0.7 U-value
Option C - Dig out trench around external walls and put in recycled
foamed glass pumice insulation (Misapor) to achieve 0.45W/m2/K U-value
Option D - Take up ground floor boards as option B and insulate trench
around external walls as option B to achieve 0.25W/m2/K U-value
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 can
control shower temperature fed direct from combi boiler.
Remove
scalding
potential
1
item
£345.00
£345.00
3
No
£85.00
£255.00
2
No
£170.00
£340.00
1
item
£1,350.00 £1,350.00
1
Item
£3,500.00 £3,500.00
2No
1
item
£4,300.00 £4,300.00
4No
1
item
£7,150.00 £7,150.00
1.1KWp
1
item
£4,500.00 £4,500.00
2.1KWp
1
item
£5,200.00 £5,200.00
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
1
item
£320.00
£320.00
1
item
£20.00
£20.00
Spray taps and flow regulators provided for wash hand basins and kitchen
8 ltr /min
sink
SAP Appendix Q extractor fans fitted whole house including bathroom and
kitchen
Install heat recovery system by installing ventilation within house and
system in loft
Option A - Install 2 panel solar thermal system and 215 ltr indirect twin
2No
coil cylinder to existing heating system to provide hot water
Option B - Install 2 x 20 evacuated tube solar thermal system as above
Option C - install 4 x 20 tube evacuated tubes and twin coil solar thermal
store
Option A - Solar photovoltaic panel to provide electricity for lights and
appliances
Option B - Solar photovoltaic panel to provide electricity for lights and
appliances
Option C - Solar photovoltaic panel to provide electricity for lights and
appliances
Waste storage and recycling area as defined by BS 5906
General sustainable homes guide and operational manual
3No bins
Low Carbon Housing Retrofit
Quantity Unit
33
131263_City-South_Manchester_v5__ 19/03/2012 12:01 Page 34
TECHNICAL APPENDICES
Wall U-values and Improvements
Based on Applied Insulation
Measures –
Appendix B
Walls are particularly complex when
considered for energy efficiency
improvements, with a number of different
common wall construction designs, and
several treatments that can be applied to
improve the thermal efficiency. To assist in
demonstrating the effectiveness of the these
various treatments, the following illustrations
have been provided as a guide to the typical
U-values that may be obtained for differing
types of wall construction, from the ‘as built’
construction.
This level of detail has not been included for
other property elements such as roofs and
floors as these have a much smaller range of
retrofit options.
1
Low Carbon Housing Retrofit
34
• Cavity wall construction referred to in
archetypes 5 to 8 is covered by Type “D” to
“E” treatments.
• Solid wall treatment referred to in Type “F”
would be applicable in system built
properties referred to in archetype 9.
2
Wall
construction
Inside
• The solid wall construction referred to in
archetypes 1 to 4 is covered in Type “A” to
“C” treatments.
existingW/
m2K-1
3
1st visit
(basic or
interim)
Outside
215mm solid wall
2.03
IWI part
215mm solid wall porous
brickwork
2.03
IWI part
340mm solid wall
Produced in partnership with Urbed
1.30
0.36
0.37
IWI part
0.33
target
0.15W/m2K-1
forecast
U-value
W/m2K-1
add rendered
30mm
phenolic
foam bonded
to 30mm
aerogel fixed
to wall with
plastic pin
fixings
EWI to finish
0.16
add external
polymer
render on
160mm
woodfibre
insulation
fixed direct to
external wall
EWI to finish
0.16
add polymer
modified
render on
120mm
mineral wool
on external
face fixed with
plastic pin
fixings
plastered
55mm
phenolic foam
on base coat
on internal
face
25mm plaster,
on brick +
half wall
C
2nd visit
internal
smooth coat
polymer
render vapour
control layer
on 100mm
woodfibre
25mm plaster,
on 215mm
brick wall
B
forecast
U-value
W/m2K-1
fermacel
board fixed to
internal wall
through
30mm aerogel
insulation
25mm plaster,
on 215mm
brick wall
A
target
0.35W/m2K-1
EWI to finish
0.16
131263_City-South_Manchester_v5__ 19/03/2012 12:01 Page 35
will have to be repaid back from the savings
achieved through the ongoing energy bill.
There are a substantial range of products
available which could equal or better the
performance of the products used in these
calculations. When undertaking a formal
technical assessment the designer should
make their recommendations based on the
products offering the highest achievable
performance and value for money to the end
user. The designer will have to bear in mind
that the cost of the works to be undertaken
single visit external
5
target
0.2W/m2K-1
forecast
U-value
W/m2K-1
single visit target
internal
0.25W/m2K-1
rendered
50mm
phenolic foam
bonded to
30mm
aerogel fixed
to wall with
plastic pin
fixings
full EWI
0.20
fermacel
board fixed to
internal wall
through
50mm aerogel
insulation
full IWI
external
polymer
render on
180mm
woodfibre
insulation
fixed direct to
external wall
full EWI
0.20
full IWI
0.20
Where there are issues as above and such as with
lime mortar and porous bricks a vapour permeable
insulant should be used. Wood fibre also has
wicking properties as well as carbon sequestration
and renewable advantages but it is costly.
0.26
plastered
80mm
phenolic foam
on base coat
on internal
face
full IWI
These measures suit a wall with feature internal
plaster or limited space so an insulant at or near
the thickness of the existing plaster is required
internally.
Further advice should be sought before using a non
permeable external insulant on old buildings eg. if
there is timber within the construction of the wall.
0.26
internal
smooth
coat polymer
render vapour
control layer
on 150mm
woodfibre
polymer
modified
render on
160mm
mineral wool
fixed to
external face
with plastic
pin fixings
full EWI
forecast
U-value
W/m2K-1
The specifications here are not the only
solutions, only suggestions for some
scenarios. These are described briefly here
as an aid.
0.25
Phenolic foam can be used internally as it is much
less toxic in a fire. Mineral wool offers vapour
permeability at a lower cost but without other
advantages. There are technical issues with it
self-supporting at high thicknesses.
Low Carbon Housing Retrofit
4
Designers should consider the insulations
materials available and assess the
performance criteria in use. There are
various manufactured products available
that will meet all the possible design
criteria requirements along with more natural
and sustainable products such as sheep’s
wool etc.
35
131263_City-South_Manchester_v5__ 19/03/2012 12:01 Page 36
TECHNICAL APPENDICES
Appendix B (continued)
1
2
Wall
construction
Inside
existingW/
m2K-1
3
1st visit
(basic or
interim)
Outside
250mm small cavity wall
1.37
IWI part
Low Carbon Housing Retrofit
36
275mm cavity wall
1.39
cavity fill
non-trad
2.58
0.79
0.51
EWI part
0.37
target
0.15W/m2K-1
forecast
U-value
W/m2K-1
add external
polymer
render on
220mm
woodfibre
insulation
fixed direct to
external wall
EWI to finish
0.16
add polymer
modified
render on
105mm
phenolic foam
on base coat
on external
face
EWI to finish
polymer
modified
render on
100mm
mineral wool
external
insulation
20mm render
on 200mm
wimpey
no-fines with
15mm plaster
F
2nd visit
injected cavity
fill, graphite
coated
polystyrene
bead achieves
0.49 W/m2K
15mm plaster,
2 standard
brick courses,
50mm cavity
E
forecast
U-value
W/m2K-1
injected cavity
fill, graphite
coated
polystyrene
bead achieves
0.79 W/m2K
20mm plaster,
2 standard
brick courses,
25mm cavity
D
target
0.35W/m2K-1
0.15
add plastered
85mm
phenolic
foam on base
coat on
internal face
IWI to finish
0.15
131263_City-South_Manchester_v5__ 19/03/2012 12:01 Page 37
4
single visit external
5
target
0.2W/m2K-1
forecast
U-value
W/m2K-1
single visit target
internal
0.25W/m2K-1
full EWI
0.19
full IWI
polymer
modified
render on
100mm
phenolic foam
on base coat
on external
face
full EWI
0.20
0.21
There may be little advantage to insulating cavities
this small and going straight to the external wall
insulation. Where there are issues with moisture in
a property, wicking permeable external insulants
will assist in creating a better internal environment
as well as insulating the property.
0.26
plastered
75mm
phenolic foam
on base coat
on internal
face
full IWI
full IWI
37
Where there is a big enough cavity for any moisture
condensing in the cavity to run to ground and also
so there is clear separation between internal and
external leaf, phenolic foam is a cost effective
insulation method due to its low thermal
conductivity.
0.26
fermacel
board on
battens with
20mm rubber
coated
Vacuum
insulated
panels
between on
levelling
basecoat
rain-screen
cladding on
proprietary
support rails
with 200mm
mineral wool
insulation
between
full EWI
internal
smooth
coat polymer
render vapour
control layer
on 140mm
woodfibre
0.26
Low Carbon Housing Retrofit
external
polymer
render on
180mm
woodfibre
insulation
fixed direct to
external wall
forecast
U-value
W/m2K-1
The specifications here are not the only
solutions, only suggestions for some
scenarios. These are described briefly here as
an aid.
The assumption here is that in non trad properties
movement and cracking mean that it is inadvisable
to put vapour impermeable insulants on the outside
of the property however as vapour pressure is
almost always outward foams are suggested here.
131263_City-South_Manchester_v5__ 19/03/2012 12:01 Page 38
TECHNICAL APPENDICES
Appendix C:
References & Sources
1. Department for Energy and Climate
Change: 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 Change
Strategy:
http://www.agma.gov.uk/cms_media/files
/gm_climate_change_strategy_final1.pdf
Low Carbon Housing Retrofit
38
5. The Building Regulations Part L1B,
October 2010.
http://www.legislation.gov.uk/uksi/2010/2
214/contents/made
6. Sustainable refurbishment CE 309,
Energy Saving Trust.
http://www.energysavingtrust.org.uk/
business/Business/Housingprofessionals/ Existing-housing/Housetypes
7. Detailed House type scenarios including
EPC/CO2 and financial savings for 8
principle archetypes:
http://www.energysavingtrust.org.uk/
Publication-Download/?oid=1532044&cg
=bestpracticedocs&ci=energyst
8. Moving Beyond the Decent Homes
Standard 2009, Sustainable Housing
Action Partnership.
http://www.shap.uk.com/
9. Greener Homes for Redbridge, Property
portfolio.
http://www.east-homes.co.uk/
CMSPage.aspx?ssbid=2987
10. Domestic low and zero carbon
technologies: CE 317, Energy Saving
Trust:
http://www.energysavingtrust.org.uk/busi
ness/Global-Data/Publications/CE-317Domestic-low-and-zero-carbontechnologies
11. Energy Saving Trust publications
including: Materials Chart: CE71
http://www.energysavingtrust.org.uk/busi
ness/Business/Housingprofessionals/Publications-and-casestudies
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 Ltd
http://www.isothane.com/
16. Vent Axia Ltd
http://www.vent-axia.com/
Interstitial and surface condensation
references
17. British Standard 5250: Code of Practice
for Control of Condensation in Buildings,
2002 and revisions, BSI.
18. Garratt, J and Nowak, F, Tackling
condensation, BRE Report 174 (BR 174),
Building Research Establishment,
Watford, 1991.
19. The Building Regulations Part F,
October 2010
131263_City-South_Manchester_v5__ 19/03/2012 12:01 Page 39
KW
Kilo Watts
Glossary of Terms
KWh
Kilo Watt Hours
AGMA
LSOA
Local Super Output Areas
MCC
Manchester City Council
mm
millimetres
MVHR
Mechanical Ventilation and Heat
Recovery
National Home Energy Rating
Association of Greater Manchester
Authorities
BRE
Building Research Establishment
BS
British Standard
CERT
Carbon Emission Reduction Target
CESP
Community Energy Saving
Programme
NHER
CHP
Combined Heat and Power
CO2
Carbon Dioxide
OFGem Office of the Gas and Electricity
Markets
CWI
Cavity Wall Insulation
DEA
PUR
Polyurethane Foam
Domestic Energy Assessor
PVCu
Polyvinyl Chloride Un-plasticised
DECC
Department of Energy and Climate
Change
PV
Photovoltaic
ECO
Energy Company Obligation
RHI
Renewable Heat Incentive
ELENA
European Local Energy Assistance
EPC
Energy Performance Certificate
EPS
Expanding Polystyrene
ERDF
European Regional Development
Fund
EST
Energy Saving Trust
FiTs
Feed-in Tariffs
GM
Greater Manchester
RDSAP Reduced Data Standard Assessment
Procedure
SAP
Standard Assessment Procedures
SWI
Solid Wall Insulation
TRV
Thermostatic Radiator Valve
U-Value Measure of thermal efficiency of a
building element
Low Carbon Housing Retrofit
Appendix D: Glossary of terms
39
131263_City-South_Manchester_v5__ 19/03/2012 12:01 Page 40
Low Carbon Housing Retrofit
Greater Manchester
Published by City South Manchester Housing Trust
for the Retrofit Standards Group
Printed by ERDF NW, Northwards Housing, Salford University and
Wigan and Leigh Housing for the Retrofit Standards Group