More than a dozen contractors have made the framework, which will be used by councils and housing associations to improve the energy performance of homes across the country, often on a street-by-street scale.

Contractors have been selected for up to five regions and whether they will handle work streams covering general refurbishment or specific energy saving measures.

The framework has been let for an initial two-year period, with an option to extend to four years.

Exact spending levels have not be quantified yet. Depending on the number of schemes to get the go-ahead it will range from £350m to £500m.

More than 150 scheme are already underway but firms on the new framework will be expected to deliver up to 400 schemes, benefiting around 90,000 homes and saving nearly 2.9m tonnes of CO2 emissions.

Regional lots
Lot 1 Southern
Lot 2 Midlands
Lot 3 North of England
Lot 4 Wales
Lot 5 Scotland