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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

BBC News Channel (December 2006), ‘Zero carbon’ homes plans unveiled,

available from http://news.bbc.co.uk/1/hi/sci/tech/6176229.stm [accessed on 21st

April 2012]

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

http://www.communities.gov.uk/documents/planningandbuilding/pdf/2077834.pdf

[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

http://www.esru.strath.ac.uk/Documents/MSc_2007/Forbes.pdf [accessed on 21st

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

http://www.tastimber.tas.gov.au/species/pdfs/Environment%20Benefits%20of%20Ti

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

http://www.forestry.gov.uk/pdf/DesigningwithScottishTimber2009Prototype.pdf/$FILE

/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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on 1st April 2012]

(Her Majesty) HM Government (2010), The Building Regulations 2010; Approved

Document F1: Means of Ventilation, London: NBS, ISBN 978 1 85946 370 3,

available from http://www.planningportal.gov.uk/uploads/br/BR_PDF_ADF_2006.pdf

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Hughes, D. (2009), 10 Ways that SAP2009 will affect you, Building Magazine,

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you/3140858.article [accessed on 1st April 2012]

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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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_12_10.pdf [accessed on 20th 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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Fig 7.3: Life cycle cost of a dwelling

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