TSG Building Services plc is the holding company of a multi-disciplined building services group, predominantly serving more than 75 Local Authorities and Housing Associations. TSG specialises in new build and modernisation programmes, as well as volume domestic and commercial boiler installations and long term maintenance contracts.

TSG has its origins in 1962 with the creation of the Swiftheat Company Limited, a small central heating installations business. A subsidiary company, Swiftheat (Contracts) Limited was formed in 1977 to deal with large contract work, followed in 1990 by the acquisition of Hale Construction (Contracts) Limited, dealing with large construction projects.

Some six years later, a further company, Swiftheat Gas Services Limited was created to specialise in gas servicing for the Local Authority market. In 2000 a holding company, TSG Building Services plc, was formed and the names of the subsidiary businesses were changed to reflect the TSG corporate brand.