The Association, whose members play a key role in thousands of building improvement projects, said the investment could be an important step towards meeting energy security and carbon reduction goals, but only if it was focused on the long-term performance of buildings and not confined to one-off installations.

The funding was announced last September but the government has now published details of how £630m will be spent through its Home Upgrade Grant (HUG) for privately owned properties, and £780m via the Social Housing Decarbonisation Fund, for homes owned by local authorities and other social housing providers.

Social housing will also benefit from a further £1.1bn of match funding from local authorities, social housing providers and charities.

The government believes its scheme will provide energy efficiency improvements for 115,000 homes with an EPC rating of C or lower and will support 20,000 construction and home retrofit jobs.

A further £409 million will be spent through the Public Sector Decarbonisation Scheme divided between 114 English public sector bodies aiming to improve the energy efficiency of hospitals, schools, universities, museums, and leisure centres. This is part of the UK’s commitment to reduce emissions from public sector buildings by 75% by 2037.

The funding will be available from April for measures including insulation of lofts and walls, new windows and doors and draft proofing measures, as well as the installation of heat pumps and solar panels.

“This is significant and important funding,” said BESA’s technical director Graeme Fox. “It could make a huge difference to the overall performance of the built environment, but only if the measures have a whole lifecycle focus.

“It is not enough to carry out one-off installations. We must look at how any retrofit measures are maintained and serviced throughout their lifetime, so they continue to meet their potential for long-term energy and carbon savings.

“This will also require a major step up of investment in training and recruitment to ensure we have a suitably competent workforce capable of taking on this considerable challenge,” said Mr Fox.

46% of UK housing has an EPC rating of C or above, up from 9% in 2008 – with 66% of social housing said to meet that standard, according to government figures. Legislation requiring all homes to achieve a C rating by 2035 is also under consideration.