Research by Halifax has revealed that large numbers of DIY enthusiasts are seriously underestimating the costs of their projects with potential negative consequences.

One in four home improvement projects go over budget, with Britons spending £4.7 billion more than they had planned.

In a statement Halifax warned that DIY projects may invalidate home insurance policies, saying: “Householders that attempt major home improvement projects, such as extensions, without employing approved contractors could risk invalidating their buildings and contents insurance cover.  Before commencing major building works, householders should check with their insurers to make sure they are covered under the terms and conditions of their policy.”

Kitchen makeovers were the most common DIY project to go over budget at 24%, followed by Bathrooms at 19%.

Martyn Foulds, senior claims manager at Halifax Home Insurance, said: ”It’s interesting to see that the major reason for spiraling costs is often due to homeowners adding extras to a project half way through. Clearly it is all too easy to get carried away with adding more expensive fixtures and fittings as the project unfolds."