Support 100 years of independent journalism.

Exorbitant energy prices mean that a well-insulated house is more valuable than ever.

Summer is drawing to a close, and the grim financial reality of rocketing energy prices will soon become all too clear as households turn on their central heating. The annualised energy price cap is set to hit £6,600 by next April, warns the think tank Cornwall Insight, which is around six times what households were paying before the pandemic. 

Exorbitant energy prices mean that having a well-insulated house is more valuable than ever. As the price of gas – which heats 85 per cent of UK residential buildings – increases, so too will energy savings from measures like cavity wall insulation, double glazing and loft insulation. 

Data from the Department for Levelling Up, Housing and Communities shows there is major regional inequality when it comes to insulation. In London, 46 per cent of houses have the highest Energy Performance Certificate (EPC) ratings of band C, B or A, with the lowest rating being G. But in Yorkshire and the Humber the figure is just 35 per cent. 

New houses tend to have higher EPC rankings, with the median EPC ranking for properties built after 2012 in England being band B, according to analysis from the Office for National Statistics (ONS). But swathes of new EPC submissions continue to fall below par: in the first two quarters of 2022, fewer than 50 per cent of houses in Yorkshire and the Humber had EPC rankings of B and C or above. This compares to a figure of just under 60 per cent in London.

[See also: Is Sizewell C actually going to be built?]

EPC band C is the minimum energy efficiency rating that all new homes must have from 31 December 2025, a measure that forms part of the government’s Net Zero 2050 strategy. A "typical" terraced house built since 1990, with reasonably efficient heating, loft and cavity wall insulation and double glazing will achieve band C. But this remains “not a very high performance bar”, says Colin Farrell, a chartered building surveyor at Faithorn Farrell Timms.

Most UK houses date back to before the 1990s, when energy efficiency design was not regulated. Around a quarter of the UK’s total greenhouse gas emissions come from the energy we use in buildings, according to the UK's Climate Change Committee. 

Policy to address inefficient buildings has so far been half-hearted, with the housing sector still recovering from David Cameron’s decision to “cut the green crap” from his policy agenda in 2013. 

Annually, the UK is currently installing only 9 per cent of the cavity wall insulation, 6 per cent of the heat pumps, and 2 per cent of the solid-wall insulation needed by 2028 to allow the country to keep pace with its net zero ambitions, according to analysis from the Institute for Public Policy Research (IPPR) think tank.

“The government should have been working round the clock to insulate homes and ensure as many households as possible benefit from lower bills,” said Kerry McCarthy, Labour’s shadow minister for climate change, after the latest energy price cap estimates were released at the end of August. “Its failure to do so despite repeated warnings risks leaving millions out in the cold.”

[See also: Is this the energy industry's "Lehman moment?"]