Npower names and shames UK’s poshest postcodes as biggest energy wasters

Npower’s chief executive Paul Massara has been given a hard time today after saying that the UK’s inefficient "old and draughty" houses mean "bills are high because [they] waste so much energy".

The comments are part and parcel of a 14-page document on how to reduce bills by the Big Six company, which rival Ofgem has said contains "incorrect and misleading" data. Npower said that network costs - those out of its control - would rise by 74 per cent by 2020.

But the energy firm has also been pointing the finger this morning, listing areas of the country whose homes lose the most heat and recommending how money can be saved on bills. It’s even brought in Location, Location, Location’s Phil Spencer to help champion the cause.

Homes in Kensington, Chelsea and Westminster have been labelled as the worst offenders by Npower, which has developed a ‘heatmap’ that shows over half of Britain’s 26m homes are wasting money by allowing heat to escape through walls and roofs.

Uninsulated walls were the leading culprits, and in Kensington and Chelsea, 83 per cent houses have failed to install insulation treatments. Westminster comes in a close second at 79 per cent.

By contrast, those who live in northern Scotland are Britain’s most energy efficient, it said, with 66 per cent of Hebridean homes "putting their southern cousins to shame by filling in the walls".

25 per cent of heat loss is through roofs. Gateshead in Tyne and Wear is the worst for loft insulation with just 27 per cent of homes meeting guidelines.

Phil Spencer comments:

Alarmingly, more than half of home owners still don’t know how to establish how energy efficient their home is and are missing out on cost savings which could run into 100s of pounds each year.

Here’s how much changes in an average three bed home could save:

• Cavity wall insulation - £140
• External Solid Wall insulation - around £490
• Loft insulation - up to £180
• New Boiler - up to £310

Npower has also caused a kerfuffle by saying that that green taxes on energy bills would more than double by the end of the decade. This has been rejected by the Department of Energy and Climate Change, which insists that lower environmental programmes will actually lower bills by up to £166 in 2020.