It won a bid for a £4.7 million grant to replace the buildings' ageing gas boilers with air source heat pumps, which are estimated to last for a minimum of 20 years and save around 14,652 tonnes of carbon emissions in that time.
The funding for the work comes from the Public Sector Decarbonisation Scheme from the Department for Energy Security and Net Zero, delivered by Salix Finance, with the council adding a further £700,000 of its own funding to complete the project.
Stroud District Council's Ebley Mill headquarters and Brimscombe Port Mill both switched to water source heat pumps in 2022, with this new project furthering its aim of becoming a carbon neutral district by 2030 and prioritising carbon reduction projects as part of its plan for the environment and climate change.
Other energy-saving measures include switching to LED lighting with passive infra-red sensors; increasing solar PV arrays; and introducing solar battery storage, to help offset increases in electricity consumption.
Stroud District Council leader, Catherine Braun, said: 'Our mission is to lead by example in the community, to help and encourage others to embrace renewable energy, and to make the changes now that are needed to equip our buildings for a low carbon future.'
Community services and licensing committee chair, Chris Brine, added: 'We are doing everything in our power through our services, projects and policies to work with partners to reach our carbon neutral goal for the district.'
Work on the buildings is expected to begin in May 2023, with an estimated completion date of March 2024.
The buildings are expected to close for up to a month for work to be undertaken, with the council aiming for the closures to be staggered and works to be done during quieter months.