The trade body’s study into consumer confidence in the UK’s builders found that as many as one third (32%) of homeowners are put off doing major home improvement works requiring a builder because they fear hiring a dodgy builder.

If all home owners had full confidence in the building industry, they would typically spend an average of £40,000 on major home improvement projects over the next five years, the report suggests.

The FMB has called for a mandatory licensing system to be introduced to increase the level of trust towards domestic builders.

Brian Berry, chief executive of the FMB, said: “A third of home owners are so anxious about the possibility of choosing a bad builder, they don’t commission any building work whatsoever. This means that the UK economy could be missing out on £10 billion of activity every year. Indeed, the FMB’s latest research shows that on average, your typical home owner would spend £40,000 on major home improvement projects over the next five years if they could be guaranteed a positive experience.

“If we were able to unlock this pent-up demand from fearful consumers, the benefit to jobs and growth would be enormous. Last year the UK experienced its slowest growth since 2012 with a rise in GDP of just 1.8 per cent. With Brexit just around the corner, it’s therefore vital that the government pulls as many leavers as possible to turbo-charge the economy and protect it from any potential economic wobbles.”

Mr Berry added: “In the longer term, we need to end the cowboy builders’ reign of terror so we can give all home owners the confidence they need to invest their cash in building work. The government should consider introducing some form of mandatory licensing system for domestic builders so that consumers know that all building firms have a base level of skill, competence and professionalism.

“Unlike in Australia and Canada, in this country anyone can be a builder and that’s why there is a significant minority of rogue traders out there giving the whole construction industry a bad name. We’re exploring mandatory licensing with industry and Government but in the meantime, our advice to home owners who are looking for a builder is to ask for a recommendation from family or friends.

“If they can’t help, consumers should approach a professional trade association like the Federation of Master Builders who can put them in touch with a vetted and inspected building firm.”