You're right to look at installing cavity wall insulation as you can make savings of www.energysavingtrust.org.uk/
At the moment, we're offering cavity wall insulation - and installation from £149. Or if you're able to have a go at installing it yourself, it costs just £3 a roll with free home delivery.
We also offer free cavity wall insulation to the over 70s or anyone receiving certain benefits. To check if you could be eligible, just click on our list of criteria: www.npower.com/web/homeinsulationoffers/index.htm or call 0800 975 6617.
