The approach to retrofitting the UK’s homes with energy saving features needs to be more targeted.

Otherwise, installing the measures won’t effectively contribute to decarbonising the UK heat sector, according to a new report from the Energy Technologies Institute (ETI).

Almost a fifth of the UK’s emissions come from heating the 28 million homes across the country.

The report suggests ‘blanket’ or ‘deep’ retrofits could cost just as much as knocking homes down and rebuilding them so measures need to be more selective.

It also says the best way to cheaply improve efficiency lies in upgrading the four million hard-to-treat cavity walls across the country. The householders may need to be targeted through energy savings reward schemes or by focusing on the increased comfort the measures would offer – saving energy doesn’t appear to be a large driver, it adds.

Andrew Haslett, ETI Chief Engineer, said: “Improving the thermal efficiency of significant parts of the existing UK housing stock over the next 30 years is an important part of a cost-effective UK decarbonisation strategy but it cannot substitute for decarbonising the supply of energy to buildings.

“Although very deep housing retrofits are technically feasible, their cost could potentially be similar to the greater than two trillion pound cost of rebuilding the entire UK housing stock so a more targeted approach is needed.”