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Timber tool kit Ruchita Dasgupta (40053991)
M.Sc. Architectural Technology and Building Performance
School of Engineering and the Built Environment
Building Performance 3
BSV11134 – Coursework 2
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Abstract
In December 2006, the Government announced that all new homes in England will
have to be zero carbon by 2016 (BBC News Channel, 2006). The urge to achieve
the target soon spread throughout the country. The aim of the report is to analyse
different timber frame construction alternatives and produce a suitable timber kit for
dwelling construction in Scotland to meet the 2016 targets for zero carbon homes.
Keywords: Zero carbon homes, building regulations, fabric energy efficiency, on-site
services and technologies, SAP
Table of Contents
Page
1.0 Introduction ……………………………………………………………… 3
2.0 2010 Building Regulation and SAP2009……………………………... 3
3.0 A way forward to 2013 and 2016..……………………………………... 5
4.0 Timber Kit for achieving FEES ……………………………………….... 5
5.0 On-site Services …………………………………………………………. 7
6.0 Cost Implications ………………………………………………………… 8
7.0 Implementation of solutions ……………………………………………. 9
8.0 Conclusion …………………………………………….………………….. 10
References
Appendices
APPENDIX 1 TIMBER AS A BUILDING MATERIAL ………………… 15
APPENDIX 2 A WAY FORWARD TO 2013 AND 2016 ……………... 16
APPENDIX 3 TIMBER TOOL KIT FOR FABRIC COMPONENTS …. 17
APPENDIX 4 THERMAL BRIDGING …………….…………….………20
APPENDIX 5 VENTILATION …………….…………….…………….….24
APPENDIX 6 EFFICIENCY OF ON-SITE SERVICES …………….….25
APPENDIX 7 COST IMPLICATIONS …………….…………….………26
APPENDIX 8 TOOL KIT EFFICIENCY …………….…………….……. 29
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1.0 Introduction
In 2009, the Climate Change (Scotland) Act created a framework to reduce
greenhouse gas emissions in Scotland by 80% (compared with 1990) till 2050 (The
Scottish Government, 2009). In addition, projections predicted an annual formation
of 223,000 new households to 2026, contributing to 27% of the CO2 emissions (HM
Government, 2008). This resulted in the amendments of Building Regulations of new
dwellings, thereby enforcing pressure on the construction industry to improve their
products to achieve maximum indoor comfort with minimum CO2 emissions.
Possessing a low embodied energy of 10MJ/kg (Greenspec), timber is a lightweight,
environmental friendly material. This property plays a significant role in minimising
the life-cycle energy consumption of timber construction systems as compared to the
other material technologies in the industry (Appendix 1 Table 1.1 and 1.2).
The timber frame housing share in Scotland is 67.8%, which is significantly high as
compared to the rest of UK (UKTFA) (Appendix 1 Fig 1.1). This puts forward a
challenge for the timber industry to upgrade the building fabric technologies and
carbon compliance strategies. The process of development requires a careful
analysis of the current trends and proposing possible alternatives, with respect to the
CO2 emissions reduction and cost implications related to them.
2.0 2010 Building Regulation and SAP2009
The Scottish government puts forward a set of regulations and guidelines to reduce
CO2 emissions in new dwellings through Technical Handbook Section 6. The current
Building Regulations for energy efficient homes were amended and enforced in
2010. The changes were incorporated to satisfy the newly adopted requirements of
SAP2009 (Hughes, 2009 and Hughes, 2010).
The ADL1a (2010) identifies five criteria for energy efficiency requirement. Though
the achieving energy efficiency standards in new dwellings are different for both the
documents, the criteria defining the regulations are similar.
2.1 Emission rates of the new dwelling
The Dwelling Emission Rate (DER) of completed dwelling must not exceed the
Target Emission Rate (TER) calculated for notional dwelling of same shape and size.
2.1.1 TER accounts for the carbon emission rates, the emission factor adjustment (of
2010 with respect to 2006) and the fuel factor related to the space heating and
cooling, air-conditioning and lighting.
2.1.2 DER incorporates the list of specifications of the details and air permeability in
the dwelling. The calculations for DER must by verified through on-site testing
after the completion of dwelling construction.
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SAP2009 considers the following new factors for DER calculation (Hughes, 2009):
1. Thermal Mass defining the ‘heavyweight’ of ‘lightweight’ construction type of a
dwelling may affect the DER by 1%.
2. The innovative use of a secondary heating or ventilation system to split the
energy demands of a dwelling are considered for SAP calculation.
3. Heat pumps are added to the database in order of their performance efficiency.
4. The average water usage target is 125litres/person/day.
5. All innovative low or zero carbon technologies (LZCT) such as solar panels,
biomass boilers, etc. are considered for SAP calculations.
6. Incidental gains from lights, appliances and cooking are excluded from the
calculations to encourage the use of efficient systems.
2.2 Standards for energy efficiency
2.2.1 U value of building fabric
The building regulations set minimum standards for the thermal transmittance (U
value) of wall, roof, floor, doors and windows.
2.2.2 Standards for building services
The fixed building services installed in the dwelling must be tested and certified by
the United Kingdom Accredited Services for quality assurance.
The architect or builder is free to combine building fabric, services and low or zero
carbon technologies to achieve DER as long as the building fabric satisfies these
standards (ADL1a, 2010).
2.3 Limiting solar gain during summers
The increase in solar gain with an enhanced level of air-tightness can lead to
overheating of the dwelling during summers. This can be mitigated by meticulously
designing the window size and its orientation, shading elements and ventilation
systems (The Scottish Government, 2011).
2.4 Mitigating the gap between designed and achieved performances
2.4.1 Party Wall
The Stamford Brook Study indicates that up to 30% of total heat loss in terraced and
semi-detached dwellings is through the cavity of the party walls in a dwelling (Lowe,
Wingfield, M.Bell and J.Bell, 2007). SAP2005 did not account for this heat loss
resulting due to party wall bypass.
2.4.2 Thermal Bridging and Air Infiltration
A significant amount of heat loss from a dwelling is due to thermal bridging from the
junctions. The junctions of walls, party walls, roof, floor, doors and windows must be
sealed properly to avoid such scenarios. Services such as air conditioning ducts,
electric conduits and pipes must be insulated and their junctions with the building
fabric must be resolved at design stages. The value of thermal bridging must be
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calculated before the construction and tested after the construction to assure
compliance.
2.4.3 Workmanship
The builder must organise proper inspections to minimise discrepancies due to
incorrect installation of the details on site.
2.5 Energy efficient operation of the dwelling
The owners of the dwellings must be provided with sufficient information and
instruction about the operation and maintenance of the building fabric and services.
3.0 A way forward to 2013 and 2016
(Zero Carbon hub, 2010) By 2016, the ‘built performance’ emissions from new
dwellings should not exceed the following limits:
10kg CO2 (eq)/m2/year for detached dwellings
11kg CO2 (eq)/m2/year for other dwellings: semi-detached, terraced, etc
14kg CO2 (eq)/m2/year for low rise apartment blocks
The improvements in the Building Regulations made every three years cannot be
considered in isolation (Domestic Working Group, 2011). This means that the
changes in the Section 6: 2013 are governed by improvements in the standards of
2010. This, in turn, will have implications on the standards of 2016 (Appendix 2
Table 2.1). Thus, the factors that help in forming the regulations for 2013 become
critical. The CLG (2012) analyzes two methods of shaping the 2013 standards:
3.1.1 Full FEES attained by achieving the FEES for 2016, by using appropriate fabric
and on-site services.
3.1.2 Interim FEES attained by achieving the half the standards for both FEES and
carbon compliance for 2016, by using appropriate fabric and on-site services
with LZCT.
To achieve dwelling standard for 2016, a dwelling has to achieve 60% improvements
over 2007 regulations (Appendix 2 Table 2.2). This will require significant
amendments and upgrading of the fabric energy efficiency standard (FEES), on-site
services and renewable systems catering the dwelling.
4.0 Timber Kit for achieving FEES
4.1 Achieving the maximum U values
The typical timber kit construction, satisfying the current Building Regulations and
achieving a U value of 0.25W/m2K, consists of 89mm x 44mm timber studs with
glass wool insulation. This construction system satisfies SAP2005. However, in order
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to achieve the standards for 2013, it is essential to satisfy the requirements of
SAP2009.
The Zero Carbon Hub Work Group (2009) proposes five specifications for the
construction of the fabric for different construction systems. The same principles are
used to achieve the building standard for the proposed timber kit, which is also
analysed by the John Gilbert Architects (2009).
4.2 Construction Details (Appendix 3)
4.2.1 Wall, Floor and Roof
With the increasing levels of specification, the U value of fabric elements is improved
by providing an additional insulation with greater thickness.
4.2.2 Door
The efficiency of the external door is enhanced by providing a secondary door with a
buffer space in between and use of insulate timber for the shutter. It is extremely
essential to draughtseal the door all around the frame for reduce thermal bridging
through the shutter-frame interface.
4.2.3 Window
Double glazed windows with standard glass trap air between the two panes and
effectively reduce the heat loss from the house. The performance is enhanced by the
use of low emissivity glass or gas such as Argon filled between the two glass panes.
Similar to the doors, it is essential to provide a seal all around the frame for reduce
thermal bridging through the shutter-frame interface.
4.2.4 Party Wall
Party wall bypass can be negated by providing a rigid insulating barrier and the
junction of wall with floor and roof. (Appendix 4 Fig 4.3)
4.3 Thermal Bridging (Appendix 4)
Thermal bridging within a dwelling is reduced by providing airtight details for all the
junctions. Air leakage can result in heat loss from a dwelling through the following
junctions:
1. Wall – Floor
2. Wall – Roof
3. Party wall – Roof
4. Wall – Window
5. Wall – Door
4.4 Air Infiltration and Ventilation Systems
The air infiltration rate for 2016 standards is 5m3/m2.h at 50Pa (Appendix 3 Table
3.2). According to Passivhaus standards, the air infiltration rate should achieve a
value as low as 0.6m3/m2.h at 50Pa (Natural Building Technology). However, for any
value lower than 3m3/m2.h at 50Pa, it is essential to provide mechanical ventilation
systems.
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Ventilation systems play an important role in maintaining the indoor air quality of a
dwelling. (Appendix 5) Four types of energy efficient ventilation systems have been
proposed in Approved Document Part F (2010) –
4.4.1 Natural ventilation with extract fans in toilets and kitchen.
4.4.2 Passive stack ventilation with stack ducts for exhaust of warm moist air in the
toilets and kitchen.
4.4.3 Continuous mechanical extract with extract system to withdraw air from toilets
and kitchen.
4.4.4 Mechanical ventilation with heat recovery with a system that utilizes the heat
from the extracted air in toilets and kitchen, mixes it with fresh air drawn from
the outdoors and exhaust it to the indoor spaces.
5.0 On-site Services
The fabric of the dwelling reduces the demand on the on-site services up to a great
extent. The lower the heat loss from the dwelling, lesser is the heating demands
(Work Group 2, 2009) (Appendix 8 Fig 8.1). Nevertheless, it is equally important to
ensure minimum use of energy during the operation of the dwelling. This reduces the
CO2 emissions of the dwelling.
On-site services are systems used for the operation of the dwelling. They cater to the
daily activities of the users and make the living environment of the dwelling reach a
desired level of comfort. These services include space heating, hot water supply and
lighting (CIBSE, 2010).
5.1 Heating Systems
Two types of heating systems can be used in dwellings:
5.1.1 Condensing Boilers
In a conventional boiler, fuel is burnt to heat the flue gases inside the system. The
heated gases are then, passed through the heat exchanger where they transfer their
heat to water. In case of a condensing boiler, the gases enter a condenser where the
additional heat is recovered. The system increases in its efficiency if the heated
water from the heat exchanger is used for both space heating and hot water supply
(Waterfield, 2007). Such boilers are called Combi Condensing Boilers. No additional
hot water storage cylinder and extra pipe works are required in this system, thus
reducing the capital cost and the heat loss through them.
5.12 Heat pumps
The heat pump uses a refrigerant in the circuit for transmitting heat. The refrigerant
gains heat as it passes through the compressor. It is then, passed through the heat
exchanger where it loses its heat to the water. The water is circulated for space
heating and hot water supply and the refrigerant flows through the circuit in ground
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or air to gain heat from the immediate surroundings (Waterfield, 2007). On the basis
of the heat source, the heat pump is called Air Source Heat Pump (ASHP) or Ground
Source Heat Pump (GSHP).
Though heat pumps do not need a fuel to heat the refrigerant, some amount of
energy is required for the circulation of the refrigerant. However, resulting in 40%
less carbon emissions (Forbes, 2007), these are more efficient and possess a lower
energy demand than boilers (Appendix 6 Table 6.1). Furthermore, the use of
underfloor heating system, instead of radiators, ensures an even distribution of heat
at the floor level across the room and improves the indoor comfort conditions.
5.2 Lighting
Amendments in SAP2009 encourage the use of energy efficient lamps, such as CFL,
etc. (Appendix 6 Table 6.2). The rated lives of these of these efficient lamps are
predicted to increase over the next 5-8 years. Moreover, with the stop of the
production of the less efficient lamps in the market, the cost of the lamps will reduce
in the future (Work Group 3, 2009).
5.3 Fuel Source
SAP2009 calculations are not only determined by the efficiency of the system
installed, but also by the type of fuel required to the run the system and their relation
with the location of the dwelling (SAP, 2009). This is because of the high emissions
from non-renewable fuel sources such as natural gas, oil or electricity from grid and
low emissions from on-site renewable technologies such as solar PV and thermal,
wind turbine or biomass. (Appendix 6 Table 6.3)
5.3.1 Solar Photovoltaic and Solar Hot Water
If the solar arrays are oriented towards south at a tilt of 35 degrees, the estimated
annual energy yield for PV system in Scotland is 855kWh/kWp (CIBSE, 2010). Use
of solar PV and SHW can reduce CO2 emissions from 325 kg/year to 645kg/year
depending on fuel displaced (Bros-W, lecture notes).
5.3.2 Wind Turbine
Scotland has an ample amount of wind resource that can be harvested for energy
generation. “For a number of reasons, planning and safety restrictions being among
them, wind turbines are a less likely option for more dwellings, especially in built-up
areas” (Waterfield, 2007). Thus, the option is not chosen by housebuilders in urban
settings.
6.0 Cost Implications
The solutions for achieving zero carbon homes can be achieved by choosing the
best technologies available in the market. However, the dynamics of the cost related
to the upgraded standards of dwelling construction undergoes significant changes.
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6.1 Cost implications due to FEES
The cost of the FEES includes the cost of the fabric elements, thermal bridging,
100% energy efficient lighting and ventilation. The efficient the technology opted,
lower is the cost of operation of the dwelling, but higher is the capital cost of the
dwelling. (Appendix 7 Table 7.1 and Fig 7.1)
6.2 Cost implication due to renewable technologies
The capital cost of renewable systems for lower specification is much higher as compared to the fabric. With the increasing FEES and decreasing energy demands, the gap between the cost of renewable systems and fabric reduce. (Appendix 7 Fig 7.2) Renewable technology omits the dependence on external fuel source provided by the government. This considers a discount rate of 3.5% adopted for Government economy wide investments and 5% applicable for private sector investments. Although life-cycle operation cost of the dwelling reduces, the capital investment related to the construction of the dwelling boosts up. Moreover, costs are added due to the regular replacement or maintenance of these systems. (Appendix 7 Fig 7.3)
6.3 Government incentives
The operational saving highlighted by Zero Carbon Hub does not include the
government incentives on the extra energy generated and supplied to the electricity
grid. The Feed in Tariff is one such scheme that may give the scope to the owners to
meet their investments made for the dwelling construction. A dwelling with a solar PV
system of 3kWp can generate up to £570 per year from the FITs. This includes £530
per year from Generation Tariff and £40 per year from Export Tariff. However, it is
seen that the Generation tariff per year has been reduced from £1060 in 2011 to
£570 in 2012 (Energy Saving Trust). This has increased the pay back duration of the
renewable systems.
7.0 Implementation of solutions
FEES for the dwelling to be built in 2016 can be achieved by the implementation of
Spec C or Spec D. Since the dwellings will possess an air infiltration rate of
1m3/h.m2, MVHR will be used for ventilation. In addition to maintaining the indoor air
quality, MVHR also reduces the energy demand on dwelling (Appendix 8 Fig 8.1).
These alternatives do not exhibit drastic change on the SAP calculations for energy
demand and CO2 emissions of the dwelling types (Appendix 8 Table 8.1).
The calculations also indicate that addition of solar PV and solar thermal for water
heating can reduce the CO2 emissions to meet the targets set for 2016. However,
Section 6.2 and 6.3 indicate that their cost with respect to the operation of the
dwelling is extremely high.
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There is a progressive increase in the innovations of the renewable technologies in
the construction industry. This means that the quality and efficiency of the systems
are improving. This will affect the future performance of the dwellings up to a great
extent and might result in the reduction of the replacement and maintenance cost of
the systems.
Passivhaus strategies indicate that it is extremely essential to construct a building
fabric that meets maximum efficiency standard before installing efficient renewable
systems (Natural Building Technology). Moreover, achieving the fabric standards
with efficient on site services for 2013 will leave a scope of choosing the most
efficient renewable systems in the future according to the market. Thus, the
implementation of ‘full FEES’ will increase the flexibility of the design.
8.0 Conclusion
The Building Regulations Section 7 and SAP2009 aim at improving the energy
efficiency of a dwelling till it reaches 70% carbon compliance level, which is the
target for 2016 zero carbon homes (Work Group 1, 2009). The development of the
kit for 2013 has to be meticulously designed so as to provide adequate flexibility to
achieve the 2016 targets and reduce the additional cost burdens on housebuilders
and owners.
The fabric must be capable of reducing the energy demands on the dwelling, thereby
reducing the CO2 emission. The fabric standards acquired by Spec C and Spec D
not only meet the standards of 2016, but also reduce the energy demands by almost
40-60% of the baseline specifications. Since the options (Spec C and Spec D) show
a marginal cost increase of 0.5-3% and very less CO2 emission difference, both
Spec C and Spec D with MVHR must be provided within the tool kit. This will offer
flexibility to the owners according to their budget.
Efficient services draw lesser energy for operation, thereby emitting less CO2
generating due to burning of fuel. Thus, ASHP and GSHP will be used as individual
and communal heating systems respectively and CFL will be installed for artificial
lighting. Considering the emissions of wood chips and pellets in biomass boilers and
the impracticality of installation of wind turbines in urban locations, solar PV will be
used for on-site generation of energy and heating water.
Though significant contributions are been made by the industry in innovating and
upgrading solar PV, the installation and maintenance of such system is an expensive
solution. Moreover, the reduction in government incentives has increased the
payback period of the system. Setting ‘full FEES’ option for 2013 will give more time
to the industry to enhance the efficiency of the maintenance capacity of solar PV. It
will also give some time to the government to rethink their strategies and provide
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some extra incentives to the owners in order to encourage them for buying these
homes.
The higher efficiency standard of a dwelling for 2016 can thus, be achieved by
proper integration of FEES, on-site services and renewable technologies. However,
the implementation of the best solutions requires proper co-ordination between the
building industry and the government. These factors will formulate a holistic tool kit
for meeting future demands of zero carbon homes in Scotland.
References
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available from http://news.bbc.co.uk/1/hi/sci/tech/6176229.stm [accessed on 21st
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Biomass Energy Centre, Carbon Emissions of Different Fuels: Fuels for Heating,
Power and Transport, available from
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al&_schema=PORTAL [accessed on 25th April 2012]
(CLG) Communities and Local Government (2012), 2012 consultation on changes to
the Building Regulations in England; Section two: Part L (Conservation of fuel and
power), London: Department of Communities and Local Government, ISBN 978-1-
4098-3320-8, available from
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[accessed on 19th April 2012]
Department of Energy and Climate Change (2010), The Government’s Standard
Assessment Procedure for Energy Rating of Dwellings: 2009 edition, incorporating
RdSAP 2009, Watford: BRE, available from
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April 2012]
Energy Saving Trust, UK, Feed In tariffs (FITs), available from
http://www.energysavingtrust.org.uk/Generate-your-own-energy/Financial-
incentives/Feed-In-Tariffs-scheme-FITs [accessed on 27th April 2012]
Forbes, R. (2007), Code for Sustainable Homes: An Evaluation of Low Carbon
Dwellings, University of Strathclyde, Department of Mechanical Engineering, Energy
Systems Research Unit, available from
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April 2012]
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Forest & Wood Products Research and Development Corporation (2003), National
Timber Development Programme: Environmental Benefits of Building with Timber,
Technical Report, Issue 2, available from
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mber.pdf [accessed on 1st April 2012]
Gilbert Architects, J. (2009), Designing with Scottish Timber; A Guide for Designers,
Specifiers and Clients: Prototype House, Second Edition, Forestry Commission
Scotland, available from
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/DesigningwithScottishTimber2009Prototype.pdf [accessed on 23rd April 2012]
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(Her Majesty) HM Government, Communities and Local Government (December
2008), Definition of Zero Carbon Homes and Non-Domestic Buildings: Consultation,
available from http://www.zerocarbonhub.org/resourcefiles/1101177.pdf [accessed
on 22nd April 2012]
(Her Majesty) HM Government (2010), The Building Regulations 2010; Approved
Document L1A: Conservation of Fuel and Power in New Dwellings, London: NBS,
ISBN 978 1 85946 324 6, available from
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(Her Majesty) HM Government (2010), The Building Regulations 2010; Approved
Document F1: Means of Ventilation, London: NBS, ISBN 978 1 85946 370 3,
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Work Group 1 (2009), Defining a Fabric Energy Efficiency Standard for zero carbon homes; Appendix A: Form and Fabric, available from http://www.zerocarbonhub.org/resourcefiles/ZCH_AppendixA_WG1_Form_and_Fabric_Final_23Nov09.pdf [accessed on 23rd April 2012] Work Group 2 (2009), Defining a Fabric Energy Efficiency Standard for zero carbon homes; Appendix B: Services, available from http://www.zerocarbonhub.org/resourcefiles/ZCH_AppendixB_WG2_Services_Final_23Nov09.pdf [accessed on 23rd April 2012] Work Group 3 (2009), Defining a Fabric Energy Efficiency Standard for zero carbon homes; Appendix C: Lighting, Zero Carbon Hub, available from http://www.zerocarbonhub.org/resourcefiles/ZCH_AppendixC_WG3_Lighting_Final_23Nov09.pdf [accessed on 23rd April 2012]
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67.8
17 21.6
10.1
0
10
20
30
40
50
60
70
80
Scotland England Wales N. Ireland
% share
APPENDIX 1: TIMBER AS A BUILDING MATERIAL
Material Energy
MJ/kg
Carbon
kg CO2/kg
Density
kg /m3
Aggregate 0.083 0.0048 2240
Concrete (1:1.5:3 eg in-situ floor slabs, structure) 1.11 0.159 2400
Bricks (common) 3.0 0.24 1700
Concrete block (Medium density 10 N/mm2)) 0.67 0.073 1450
Aerated block 3.50 0.30 750
Steel (general - average recycled content) 20.10 1.37 7800
Timber (general - excludes sequestration) 10.00 0.72 480 - 720
Table 1.1: Environmental impact of different building materials
Source: Greenspec
Element
Description MJ/m2
Floors
(including flooring, framing,
footings, reinforcement,
DPC, membranes, etc.)
Timber suspended, timber sub-floor
enclosure
740
Timber suspended, brick subfloor wall 1050
Concrete slab-on-ground 1235
Walls
(including as appropriate,
framing, internal lining, insulation)
Weatherboard, timber frame 410
Brick veneer, timber frame 1060
Double brick 1975
Windows
(including 3mm glass)
Timber frame 880
Aluminium frame 1595
Roofs (including plasterboard ceiling, R2.5 insulation, gutters, eaves)
Concrete tile, timber frame 755
Concrete tile, steel frame 870
Metal cladding, timber frame 1080
Clay tile, timber frame 1465
Table 1.2: Embodied energy of different construction systems
Source: Forest & Wood Products, 2003
Figure 1.1: Timber frame housing shares in UK
Source: UK Timber Frame Association
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APPENDIX 2: A WAY FORWARD TO 2013 AND 2016
Fabric elements U value [W/m2K]
2007 2010 2013 2016
Wall 0.30 0.25
?
0.18
Party Wall NA 0.20 0.00
Floor 0.25 0.20 0.13
Roof 0.20 0.18 0.13
D-W 2.20 1.80 1.40
Thermal Bridging 0.08 0.04 0.04
Air Infiltration @ 50Pa [m3/m
2.h] 10.00 7.00 5.00
Table 2.1: Past, Current and Future Standards for FEES
Source: Domestic Work Group, 2011
Date 2010 2013 2016 2030
Carbon improvement as compared to Section 6, 2007
30% 60% Net zero carbon in use
Total life zero Carbon
Table 2.2: Timeline for Zero Carbon Homes
Source: John Gilbert Architects, 2009
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APPENDIX 3: TIMBER TOOL KIT FOR FABRIC COMPONENTS
Fig 3.1: Alternative for wall construction
Source: Work Group 1, 2009
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Fig 3.2: Alternative for floor and roof construction
Source: Work Group 1, 2009
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Baseline Spec A Spec B Spec C Spec D
Doors Specification Insulated steel faced doors with partial glazing.
Insulated steel faced doors with limited glazing.
Insulated steel faced doors with no glazing.
Insulated steel faced doors with no glazing, thermally broken frame.
Insulated steel faced doors with no glazing, thermally broken frame.
U value W/m
2K
1.6 1.4 1.2 1.0 1.0
Windows Specification Double glazed Upvc windows with Low-E coating (hard).
Double glazed Upvc windows with Low-E coating (soft).
Double glazed Upvc windows with Low-E coating (soft).
Triple glazed Upvc windows with Low-E coating (soft).
Triple glazed Upvc windows with Low-E coating (soft).
U value W/m
2K
1.8 1.5 1.4 0.8 0.8
Table 3.1: Alternative for doors and windows
Source: Work Group 1, 2009
U value [W/m2K]
Baseline Spec A Spec B Spec C Spec D
Wall 0.25 0.24 0.18 0.15 0.10
Floor 0.20 0.20 0.18 0.13 0.10
Roof 0.16 0.15 0.13 0.11 0.10
Doors 1.60 1.40 1.20 1.00 1.00
Windows 1.80 1.50 1.40 0.8 0.8
Air Infiltration @
50Pa [m3/m
2.h]
7 5 3 1 1
Thermal Bridging W/m
2K
0.08 0.06 0.05 0.04 0.02
Table 3.2: comparison of FEES for different alternatives
Source: Work Group 1, 2009
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APPENDIX 4: THERMAL BRIDGING
Fig 4.1: Junction between wall and warm roof; Source: The Scottish Government, 2010
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Fig 4.2: Junction between wall and cold roof; Source: The Scottish Government, 2010
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Fig 4.3: Junction between party wall and roof (section) or party wall and wall (plan); Source: The
Scottish Government, 2010
Fig 4.4: Junction between wall and ground floor slab; Source: The Scottish Government, 2010
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Fig 4.5: Junction between wall and window head; Source: The Scottish Government, 2010
Fig 4.6: Junction between wall and door/window; Source: The Scottish Government, 2010
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APPENDIX 5: VENTILATION
Figure 5.1: Ventilation systems for enhanced air infiltration rate
Source: Approved Document Part F, 2010
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APPENDIX 6: EFFICIENCY OF ON-SITE SERVICES
SN Heating System Specifications
A Individual
1 Gas condensing boiler
Efficiency 95%
Emitter Radiators
2 Gas combi condensing boiler
Efficiency 95%
Emitter Radiators
3 ASHP
Efficiency 250%
Emitter Underfloor
B Communal
1 Gas boiler
Efficiency 86%
Emitter Radiators
2 GSHP
Efficiency 320%
Emitter Underfloor
Table 6.1: Efficiency of different heating systems
Source: CIBSE, 2010
Lamp Efficiency [lm/W] Rated life [hrs] Colour temperature
GLS/Tungsten 12 1000 2700K
Halogen 20 2000-3000 2900-3100K
CFL 55-60 7000-9000 2700-4000K
LED 30-50 45000 3000/4000K
OLED 15 5000 100cm2
Table 6.2: Efficiency of different lamps used for artificial lighting
Source: Work Group 3, 2009
Fuel CO2 emissions [kgCO2/kWh]
Oil 0.274
Natural Gasa 0.198
LNGa 0.198
LPG 0.245
Electricity (standard tariff) 0.517
Wood chips 0.009
Wood pellets 0.028
Wood logs 0.008
Solar PV 0.000
Wind turbine 0.000
Table 6.3: CO2 emissions generate by different fuel sources
Source: The Scottish Government (2012); aSAP (2009)
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APPENDIX 7: COST IMPLICATIONS
Dwelling type Capital Cost of Energy Efficiency [£]
Baseline Spec A (NV)
Spec B (NV)
Spec C (NV)
Spec D (MVHR)
Semi detached 71,280 72,559 74,882 79,690 83,564
Detached 107,380 109,326 113,231 120,760 126,921
Small ground floor apartment 47,300 47,975 48,717 51,400 53,459
Table 7.1: Cost of different alternatives for FEES
Source: Work Group 4, 2009
Fig 7.1: Cost verses energy demands
Source: Work Group 4, 2009
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Fig 7.2: Cost implications due to FEES, on-site services and renewable technologies
Source: Work Group 4, 2009
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APPENDIX 8: TOOL KIT EFFICIENCY
Fig 8.1: Impact of increasing FEES on energy demand of a dwelling
Source: Work Group 1, 2009
Dwelling type
Area [m
2]
Spec C Spec D
W/o PV PV + SWH W/o PV PV + SWH
Small Apartment
43
Energy Demand [kWh/m
2/year]
146 -30 142 -33
SAP rating 83 107 83 107
CO2 emissions [kg/m
2/year]
24 -12 23 -12
SAP rating 85 108 85 108
Mid-terrace 76
Energy Demand [kWh/m
2/year]
121 16 119 14
SAP rating 81 99 81 99
CO2 emissions [kg/m
2/year]
19 -1 19 -2
SAP rating 84 101 84 102
Detached 118
Energy Demand [kWh/m
2/year]
114 43 110 39
SAP rating 79 93 80 94
CO2 emissions [kg/m
2/year]
18 4 18 4
SAP rating 82 96 83 97
Table 8.1: SAP calculations for Spec C and Spec D
Source: Author