New figures from Lloyds TSB Insurance show the extent to which rogue traders are costing UK homeowners money.
Research from the firm revealed the average cost of a botched job is £460 – something that could increase for larger jobs such as conservatories or roof light installation.
The study found the total number of these ill-fated home improvements was more than 4.6 million in the past 12 months.
It equates to one in ten Brits having to correct work to their property – a 16 per cent rise on the previous years figures.
Lloyds TSB Insurance managing director Phil Loney explained the company has created a guide to "rooting out the rogues" to help customers choose builders.
"Rogue traders are on the increase and costing unsuspecting homeowners thousands," he said.
The news comes a month after Lloyds TSB revealed there has been a rise in the number of three-generation households in the UK.