Homeowners in the UK could be wasting billions of pounds every year by failing to take the necessary precautions when using a builder, according to new research by the National Federation of Builders.

Over a quarter of homeowners surveyed by the professional building body said they wouldn't bother asking a builder for references before inviting them on site to start work. Fifty per cent said they wouldn't take out a warranty on the work, although an unwarrantied modification could decrease the future value of the property.

The research also showed that:

• Over a third of homeowners wouldn't spend any longer than 60 minutes sourcing, researching and appointing a builder.
• Half would happily pay an advance cash deposit for building work, regardless of whether it was required or not.
• One in five wouldn't bother checking if their builder had public liability insurance - a critical requirement if your builder injures a member of the public.
• Almost 50 per cent would accept a VAT-free quote from a tax-dodging builder if it meant saving them money, although they wouldn't have any comeback should the work prove unsatisfactory.

Tony Maynard, chief executive of the NFB, which represents almost 4,000 professional firms, said: "It's no surprise that so many homeowners are getting caught out by cowboy builders when they're failing to take the right precautions. Homeowners spend an estimated £10.9 billion every year with builders having essential repair, maintenance and improvement work done on their home.

"Our message is simple - do your homework and don't take unnecessary risks. Your home is the most important purchase you're ever likely to make and your biggest asset - so why tempt fate?

"People can take hours deciding on a new washing machine yet they seem willing to spend only half the time planning something that costs ten times as much. We're urging homeowners to get clued up and protect their investment. Simply by spending the time, effort and energy into making sure they've got the right man for the job, homeowners can save a lot of headaches and heartaches further down the line while safeguarding the value of their property."