Introduction to energy efficient house extensions

In the UK, homes are responsible for approximately 28 per cent of carbon dioxide emissions, a major contributor to climate change.

Domestic emissions arise from the use of energy for space and water heating, cooking, and the use of lighting and electrical appliances. To meet our international commitments and tackle climate change, we must significantly reduce energy related emissions in homes. By following Best Practice standards, new build and refurbished housing will be more energy efficient and will reduce these emissions, saving energy, money and the environment.

When a household requires more space or better accommodation, extending a home is often a very practical and cost effective alternative to relocation. Extensions can be designed to suit the location of the house (exploiting views, making good use of daylight, etc) and to provide the precise accommodation that the household requires, in the best arrangement. However, building an extension involves a significant investment of time and money, and the resulting accommodation will probably remain in use for at least sixty years, so it is important to design to a good standard. Many homeowners engage architects to assist them with the designs of their extensions; others rely on reputable builders; a few design and construct their extensions themselves.

This guide is for homeowners, designers and builders to use together. It explains how to incorporate Best Practice energy efficiency features into the design and specification of domestic extensions, and deals with:

• energy efficient extension shapes;

• insulation of external walls, exposed floors and roofs;

• specifying energy efficient, high-performance windows;

• limiting thermal bridging and air leakage;

• providing controlled ventilation;

• providing efficient heating;

• specifying energy efficient lighting.