Proposal to achieve Code for Sustainable Homes Level 3 for a development of 7 detached dwellings

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Suzan Robinson
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1 Duchy Homes Site: Cantley Lane Doncaster Proposal to achieve Code for Sustainable Homes Level 3 for a development of 7 detached dwellings 22 nd February 2013 Leanne Brooksbank Accredited Energy & Code for Sustainable Homes Assessor (Stroma) STRO04241 Plasmor Limited PO Box 44 Womersley Road Knottingley West Yorkshire WF11 0DN technical@plasmor.co.uk

Accredited Energy & Code for Sustainable Homes Assessor (Stroma) STRO04241 Plasmor Limited

2 The Code for Sustainable Homes is an environmental assessment method for rating and certifying new homes against nine categories of environmental concern and sustainable design. The nine categories assessed are; 1. Energy and CO 2 Emissions 2. Water 3. Materials 4. Surface Water Run Off 5. Waste 6. Pollution 7. Health and Well-being 8. Management 9. Ecology The Code sets mandatory requirements at each level. To obtain Code for Sustainable Homes Level 3 certification the assessed dwellings must achieve compliance to SAP and the Building Regulations Part L1a and must comply with the mandatory elements of the code and achieve a maximum internal water consumption of 105 litres per person per day and achieve a total overall assessment score of at least 57 points. Initial SAP calculations have confirmed that a fabric first strategy will meet the requirements of SAP and Part L1a see Appendix A, Specification, and the properties will score highly in ENE 1 (Dwelling Emission Rate) and ENE 2 (Fabric Energy Efficiency) the properties achieve significantly above basic Building Regulation compliance through the use of high insulating products, smart heating controls and reduced thermal transmittance between junctions using Accredited Construction Details and Psi Values from Birtley Lintels. Credits in ENE 7 (Low and Zero Carbon Technologies) have been discounted as it is more favorable to adopt improvements which offer lifetime solutions to the dwellings carbon footprint. 2

Ecology The Code sets mandatory requirements at each level.

3 Other credits allocated within the Energy category, although not mandatory, include the installation of Energy Display Devices which allow the occupants to measure and benchmark their energy cost and consumption and set targets to reduce the amount they use. The installation of external drying facilities to promote a reduction in energy consumption to assist in the drying of clothes is advised; secure cycle storage facilities to promote the use of a more sustainable form of transport is proposed; the space and services provided to promote working from home such as: adequate space, lighting and ventilation, electrical and telephone points in easy reach of a desk and sufficient day lighting to promote a comfortable working environment typically referred to as the home office. To reduce the water use in the properties and to satisfy the mandatory requirements of the water category an internal water consumption target of not more than 105 litres per person per day is thought to be achievable through the installation of flow rates to sanitary appliances. To encourage the recycling of rainwater and reduce the amount of potable water used a 200 litre rain water butt will be provided to the properties. At such an early stage in the development an assumption to the materials used can be made with a commitment to specifying materials known to having lower environmental impacts over their lifecycle. This applies to the materials used in the external walls, roof, ground floor and upper floors and windows and extends to the non-mandatory elements of the materials category such as the basic building materials (staircases, internal walls, upper floors) and the finishing elements (fascias, skirting, furniture). A high credit allowance is anticipated in this category due to procedures already being in place to ensure materials are responsibly sourced. 3

The installation of external drying facilities to promote a reduction in energy consumption to assist in the drying of clothes is advised; secure cycle storage facilities to promote the use of a more

4 To design surface water drainage for housing developments which avoids, delay and discharge rainfall run-off to watercourses and public sewers and reduces the risk of flooding the mandatory element of Surface Water Run off must be met by a suitably qualified person i.e. a Hydrologist or Water Engineer. The mandatory element does not offer a credit however an additional credit is anticipated for no discharge to watercourse for rainfall depth up to 5mm, this is met through the installation of Permeable Paving to driveways and a multiple linked Soakaway system for the drainaway of surface water. Credits are available for SUR 2 (Flood Risk Assessment) and a credit could be awarded if the site was located within Flood Zone 1 as identified by the Hydrologist. To provide adequate internal and external waste storage each dwelling must be supplied with dedicated recycling bins for segregating recyclable waste and adequate storage for bins externally with applicable disabled access required; level threshold, gentle approach, a hard surface with a 1500mm diameter turning circle. This also applies to composting bins (for WAS 3) which are to be located in the rear gardens. Duchy Homes already operate a site waste management plan and so the inclusion of credits within WAS 2 is high with commitments and procedures set to direct and divert waste from landfill. The proposed specification used in the SAP calculations has allowed for materials used having a low global warming potential (GWP) less than 5 (in manufacturing and installation). This promotes the reduction of emission gasses with high GWP and therefore one credit can be awarded along with a further three credits in POL 2 (Nox Emissions) as the boilers specified have dry NO x less than or equal to 40mg/kWh. The site plan shows existing retained trees on the development. This could reduce the amount of daylighting allowable for the Health and Wellbeing category (HEA 1), 4

The mandatory element does not offer a credit however an additional credit is anticipated for no discharge to watercourse for rainfall depth up to 5mm, this is met through the installation of

5 particularly to Plot 7 and the rear of Plot 6. The remaining Plots 1-5 are expected to achieve required daylighting in the living room, dining room and kitchens and the required daylight value for the room designated as the home office to allow for an accurate example of points available, two credits in this category have been incorporated. All plots achieve a credit by default in HEA 2 (Sound Insulation) as all plots are detached. Further credits within this category are anticipated in HEA 3 (Private Space) as all plots have level threshold patio style doors to the rear with adequate space required in the Code for Sustainable Homes of 1.5m 2 per bedroom. The management and operation of each dwelling must be fully utilized to show the occupants the most efficient way to run their home and make the most of local facilities. This will be done by providing each dwelling with a Home User Guide (HUG) which is fully compliant with all Code for Sustainable Homes checklists Man 1 Part 1 and Part 2. The HUG will advise them on fuel saving techniques, water use, recycling and waste information including composting advice, sustainable DIY and will provide them information relating to the site and surroundings such as local amenities, public transport and emergency information. Full credits are anticipated within this category. To mitigate environmental impacts to the surrounding areas of the development, Duchy Homes are committed to following commitments and best practices for Air (dust) pollution from site activities and Water (ground and surface) pollution. This will allow for 1 credit allocated to the assessment. The Ecology category of the Code for Sustainable Homes is to be assessed by a suitably qualified ecologist so credits are difficult to assume. However, the development site plan shows existing trees and providing any existing ecological 5

for an accurate example of points available, two credits in this category have been incorporated. All plots achieve a credit by default in HEA 2 (Sound Insulation) as all plots are detached.

6 features are protected one credit can be awarded based upon this for ECO 1 (Ecological Value of Site) and ECO 3 (Protection of Ecological Features). It is also assumed that some Ecological Enhancement to the site will be adopted as specified under ECO 2 and as the proposed example of the linked soakaway system (shown in Appendix 2) creates a woodland SuDs feature which will encourage biodiversity and further wildlife than is currently there it can be assumed that additional credits will be achieved offering a further credit for ECO 4. 6

It is also assumed that some Ecological Enhancement to the site will be adopted as specified under ECO 2 and as the proposed example of

7 Summary of score The table below shows a summary of the score achievable through the implementation of the above, which is the proposal to meet Level 3 of Sustainable homes. Category Credits Awarded Weighting Points Energy & CO2 Emissions ENE 1 Dwelling Emission Rate ENE 2 Fabric Energy Efficeincy ENE 3 Energy Display Device ENE 4 Drying Space ENE 5 Energy Labelled White Goods ENE 6 External Lighting ENE 7 Low or Zero Carbon Technologies ENE 8 Cycle Storage ENE 9 Home Office Water WAT 1 Internal Water Use WAT 2 External Water Use Materials MAT 1 Environmental Impact of Materials MAT 2 Responsible Sourcing of Materials MAT 3 Responsbile Sourcing of Materials Surface Water Run Off 0 SUR 1 Management of Surface Water Run-Off SUR 2 Flood Risk Assessment Waste WAS 1 Storage of Non-Recyclable Waste WAS 2 Construction Site Waste Management WAS 3 Composting Pollution POL 1 Global Warming Potential of Insulants POL 2 NOX Emissions Health and Wellbeing 0 HEA 1 Daylighting HEA 2 Sound Insulation HEA 3 Private Space HEA 4 Lifetime Homes Management MAN 1 Home User Guide MAN 2 Considerate Constructors Scheme MAN 3 Construction Site Impacts MAN 4 Security Ecology ECO 1 Ecological Value of Site ECO 2 Ecological Enhancements ECO 3 Protection of Ecological Features ECO 4 Change in Ecological Value of Site ECO 5 Building Footprint LEVEL ACHIEVED - CODE LEVEL 3 Total Points

34 ENE 4 Drying Space 1 1.17 1.17 ENE 5 Energy Labelled White Goods 1 1.17 1.17 ENE 6 External Lighting 2 1.17 2.34 ENE 7 Low or Zero Carbon Technologies 0 1.17 0 ENE 8 Cycle Storage 2 1.17 2.34 ENE 9 Home Office 1 1.

8 Appendix A 8

9 Appendix B 9

10 10

Code for Sustainable Homes Guidelines

Canoldir Penrhos Anglesey LL65 2TS Phone: 01407 860666 Email: saps@easonline.co.uk www.easonline.co.uk Code for Sustainable Homes Guidelines A CSH rating is the responsibility of the Developer/ Architect