A staggering 15 million homes in England and Wales could need an energy efficiency retrofit to meet the proposed target of an EPC band C rating by 2035.

A new report by Halifax suggests this target might mean 60% of total housing stock might need an upgrade that will improve energy efficiency.

The analysis, which is based on data from the properties the bank lends mortgages on, finds that an estimated 4.2 million homes that were built before 1900, have an average EPC rating of E.

It said just one-in-ten of pre-1900 homes meet EPC C.

Andrew Asaam, Mortgages Director at Halifax, said: “The 50% increase in the fuel cost cap is going to have an impact on everyone’s energy bills, in all but the most modern homes that impact is going to be significantly more.

“The majority of our homes fall short of the average C rating the government aspires to, which means we’re wasting money and harming the environment heating our homes.

“Further fuel price increases are only going to mean we’re spending more to live in colder homes unless we act.”