A significant number of homeowners have damaged their properties while attempting to copy DIY TV programmes, it has been claimed.
Halifax reports that 12 million people said they were "inspired" to undertake home improvements having watched such programmes in the last five years.
However, three-quarters of a million people have damaged their homes while attempting these projects, with the average cost of repairs reaching £484, the firm said.
Vicky Emmott, Halifax Home Insurance, said: "It all looks so simple on TV, making it easy to forget that the work on makeover shows is being carried out by highly trained and skilled professionals."
Attempting to carry out work on some areas, such as electrics and plumbing, could invalidate home insurance policies, she added.
Last month, a survey conducted by the company revealed that redecorating was the most popular home improvement project carried out by homeowners in the UK, followed by gardening and buying new furnishings.
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