The four-year deal could be worth up to £500m and will offer both domestic and commercial services for clients like housing associations, NHS trusts and education providers.

Three-quarters of the firms making the list are SMEs. They are spread across 10 lots providing a mix of services from consultancy to design, servicing, maintenance and installation.

The framework incorporates a selection of renewable or decarbonising technology applications from air and ground source heat pumps to solar thermal, electric heating and hot water systems.

For the first time, the framework also features an education specific lot in partnership with the Department for Education, developed to support schools, colleges, academies and further and higher education colleges with their heating requirements.

Peter Francis, director of operations at Fusion21 said: “Developed in response to member and market demand, this framework provides regional coverage with an enhanced scope and access to both larger contractors and SMEs.

“Following the government’s target to deliver decarbonisation and as the use of renewable technologies continues to rise, we’re delighted to offer our members access to a range of sustainable heating solutions tailored to their requirements.

“Other member benefits include flexible call-off processes, greater efficiencies, support from technical procurement specialists and social value delivery aligned to organisational priorities.”

To date, Fusion21 has saved its members more than £226m through the procurement process, created 6,500 jobs and generated more than £84m of social impact.