There is a widespread failure by people in the UK to notify their insurer about major home improvements, according to MoneySupermarket.com.

The comparison site polled people on whether they would tell their insurance provider if they made structural improvements to their home, such as adding an extension or a conservatory, or converting a loft. 26% said they would not update their insurer; 21% said they didn’t think it was necessary, while 3% couldn’t be bothered and 2% would avoid it because it could increase the cost of their premium.

The research found the problem is worst among Brits living in Yorkshire and the Humber – 30% would fail to fill in their insurer.

Structural improvements to a home may not have a financial impact on a home insurance premium as many insurers only increase premiums once the value of your property increases significantly, typically £10,000 plus. Despite this, failing to notify the insurer of structural changes to a property could void the policy.

“There is no doubt we are a nation that loves DIY and home improvement. We take pride in our homes and like to make the most of all available space. It will come as no surprise that every year, 200,000 of us carry out a loft conversion or the like to our homes,” said Hannah Mercedes-Skenfield, insurance spokesperson at MoneySupermarket.com.

“I urge all those people carrying out home improvement work, whether it is a luxurious loft conversion or comfortable conservatory, to inform their home insurance provider as soon as the works are complete and the room is being used. Work being carried out on a property would be covered by your builder’s insurance so it’s vital to check they have all the correct policies place.

“Once the work is complete, you need to upgrade both the buildings and contents insurance where necessary. In many cases, some changes to your policy will not have any impact on the premium price, but not informing your insurer could cost you dearly as the cover could be voided as a result. Those concerned about cost, especially after forking out for those home improvements, should shop around for the best deal on home insurance cover; on average Brits can save £119 a year on a combined buildings and contents insurance policy.”