A boom in home renovations being carried out this year has caused an increase in problems with rogue traders, as consumers fail to check if tradesmen have proper credentials.
According to the survey, some 7 million projects have been undertaken so far in 2014 - the same number as took place during the whole of 2013.
However, the number of problems with rogue traders and consumers unhappy with the work being carried out has also increased.
Common problems include poor quality work (38%) and a lack of professionalism (22%), with cracking, electrical problems and structural issues the result commonly being reported. Some 6% of those questionned also said they have previously paid a tradesman for work and then been unable to find them.
To combat the rise in rogue tradesmen, Which? has launched a Trusted Traders scheme to recognise reputable traders. The scheme offers complaints handling through Ombudsman Services.
Lewis Shand Smith, chief ombudsman for Ombudsman Services, said: “Without an ombudsman for the trade sector, civil court is the only route for many consumers who are unhappy with their renovations. This can be an expensive and lengthy process, while ombudsmen resolve disputes quickly and fairly and the process ends in a decision that is fair to both parties.