Risking lives, homes and legal trouble for themselves and those who live at the address, as this work needs to be completed by a certified professional or approved by building control.

In over a quarter (29%) of cases where people did the work themselves, it was completed without ever obtaining building control approval or certification from a registered installer. A lack of public knowledge is fuelling the problem.

Nearly two-fifths (39%) of those who have undertaken gas or electrical DIY projects were unaware that conducting such work without proper certification or sign off is illegal – a mistake that can lead to unlimited fines and even prosecution.

Most commonly, DIYers move or install kitchen or bathroom sockets themselves (9%) or install electric showers, cookers, or storage heaters (8%).

Potentially illegal DIY tasks done

Source: Direct Line business insurance 2025 

Less than half (45%) of those that complete restricted work themselves are getting it approved: nearly a quarter (22%) asked a qualified engineer to inspect the work and issue a certificate as a favour, and almost a sixth (17%) asked a qualified engineer to inspect the work and issue a certificate for a small fee.

A further 6% did the work themselves and then arranged for it to be approved by their local authority.

A proportion of adults (15%) do not realise that faulty DIY work could cause serious health risks, injury, or even death, and one in eight (12%) mistakenly believe local authorities cannot insist they put dangerous work right at their own expense.

The consequences extend beyond health and legality – they can also impact future property sales. A fifth (22%) of adults are unaware that failing to provide certificates of compliance with building regulations could cause issues when it comes to selling their home.

Of those who attempted gas or electrical DIY jobs, two in five (41%) said it looked straightforward, a third (31%) were trying to save money, and a quarter (24%) were encouraged by videos on social media.