Cavity wall insulation

Cavity wall insulation is a fantastic way to significantly reduce the amount of energy you need to heat your home. The average house could reduce heating costs by 15%. In fact, between 2002 and 2005 around 800,000 households installed cavity wall insulation. It is estimated that this will have saved nearly 400,000 tonnes of CO2, enough to fill the new Wembley Stadium 47 times.
Advantages:
Easy to install, without disturbing occupants -It's a simple process and is normally completed within three hours, without damage or mess to your house or garden. Grants are available
Disadvantages:
Need to have cavity walls (houses built since 1920s). Installation may create some fumes.
Cost: £ 500.00 each / per house
Estimated annual £ saving: £ 90 Payback: 5 years
Energy saving trust
http://www.energysavingtrust.org.uk/home_improvements/home_insulation_glazing/cavity_wall_insulation
Cavity Insulation Guarantee Agency
http://www.ciga.co.uk/