How is a building’s environmental performance best demonstrated?

• Examine the range of tools available for assessing the overall impact of performance of buildings. Those tools most widely adopted have been developed by the Building Research Establishment (BRE) – see under Further Resources and in the Useful Contacts section.
• Use the chosen assessment to demonstrate to planning and building control officers that sustainability issues have been fully addressed from an early stage.

What are the main themes that characterise sustainable building design?

Consider different approaches to achieving sustainable design. The following themes are not necessarily all compatible but they require an emphasis on high insulation levels and a sensitive fit with local landscape / townscape:

• Passive Solar - Use of the sun to warm a building interior directly through windows or a “sunspace” (e.g. conservatory), and of thermal mass (see below) plus insulation to store the heat.
• High Thermal Mass - Use of materials with a high capacity to absorb heat energy within a building structure that can be later released as air temperature drops.
• Timber Frame - A form of lightweight construction using timber to provide a structural frame (normally clad with brickwork to provide the waterproof layer) and faster heat-up capability.
• Earth Sheltered - Earth covering of building, except south facing side, to provide additional insulation and/or to reduce visual impact and the area of exposed external wall.
• Natural Ventilation - Use of natural cross air flows controlled by building users.
• Low Impact - An unobtrusive form of building, fit for its purpose and setting, using local materials.
• Autonomous - Uses local or own resources to supply energy, drainage and water needs.

How can the energy used to manufacture and deliver materials (‘embodied’ energy) be reduced?

• Endeavour to reuse materials and topsoil already on site, and give preference to low energy materials.
• Source materials locally, thus reducing delivery journeys and supporting the local economy. Ensure that contractors do likewise by examining their supply chain.
• Use reclaimed materials (e.g. second-hand timber) and recycled materials (such as glass / concrete or brick rubble for aggregates) for construction.

How can the longevity of a building be increased?

• Incorporate durable materials and products - although be aware of the environmental damage that some treatments can cause (see Health & Pollution)
• Provide features (such as deep roof overhangs) that protect the building from extreme weather.
• Install adjustable ventilation and blinds to prevent build-up of heat from sunlight.
• Be aware of ground stability, especially where risk of subsidence, and design foundations accordingly.

How can design allow for future adaptations to the building?

• Design flexible spaces for changing spatial requirements of building occupiers, and consider, for example, the merits of non-structural internal walls.
• Incorporate generous storage space standards with built-in expansion areas e.g. in the loft.
• Ensure that service installations are easily accessible, preferably on outer or spine walls for future flexibility.

How can design improve building accessibility?

• Consider the following: gradients, accessible routes, entrance position, level changes, lifts, ramps, disabled parking, internal features etc, and be aware of security considerations.
• Consult Part M of the Building Regulations. Adopt Lifetime Homes standards.

What other low impact materials should be specified?

• Order new timber from certified (preferably Forestry Stewardship Council accredited) sources.
• Investigate recycled metals that are often economically attractive, especially steel.
• Specify high quality timber window frames rather than uPVC or aluminium.