The Nationwide has quantified the cost of energy to properties with different EPCs – and that’s despite the Energy Price Guarantee. 

Under the guarantee a typical UK household will now pay an average of £2,500 a year on their energy costs until next April – but not every property will have an EPC at or above the average.

Nationwide chief economist Robert Gardner says: “Despite this intervention, energy costs are still going to be around 80 per cent higher than a year ago, even after taking account of the £400 energy support scheme discount. 

“It is important to note that the cap is on the unit price charged to consumers, rather than a maximum bill a household can be charged. Running costs for less energy efficient properties tend to be considerably higher, leaving these households particularly vulnerable to price rises.”

Gardner says that average energy costs for the most energy efficient properties (those rated A to C as reported on Energy Performance Certificates) are expected to rise to around £1,800 per year, compared with around £1,000 a year ago.

He states: “Typical bills for D-rated properties (the most common type) are set to rise to £2,600 a year. Those in E-rated properties will be paying around £120 a month more than last winter. However, those living in the least efficient properties (rated F to G) will see average bills rise to circa £4,500, an extra £185 a month compared with a year ago, though these properties make up two per cent of the stock of housing with a mortgage.

“The cost-of-living crisis is set to disproportionately affect lower income households as they spend a higher proportion of their income on essentials (food, gas and electricity). Lower income households are also much less likely to have accumulated savings, so they will find it more difficult to cover the increase in these costs.”

Gardner concludes there is additional uncertainty because the blanket two year guarantee offered by the Liz Truss government was scaled back to six months.