Watchdog Trading Standards is investigating attempts to use the Green Deal to defraud householders.

Caerphilly Trading Standards said it had received 17 complaints from people asked to pay an “administration fee” for promised free insulation work. Tim Keohane, senior trading standards officer in Caerphilly, said none of those under investigation were registered under the Green Deal scheme.

Brian Berry, chief executive of the Federation of Master Builders, said the Government needed to do more to promote the Green Deal in order to ensure consumers had knowledge of the standards to protect them from fraud. “This [type of scam] undermines the reputation of the building industry. Image is very important and [fraud] gives the public less confidence in using builders in the future.”