‘Dodgy DIY’ could leave households thousands out of pocket

Homeowners attempting DIY jobs in 2026 are being warned they could unknowingly invalidate their home insurance and have future claims refused.

With spring approaching, it’s peak season for DIY as lighter evenings and better weather give homeowners the chance to assess, repair and improve their homes.

Home insurance experts at Quotezone.co.uk say claims could be rejected if damage is traced back to poor workmanship, unsafe installations or undisclosed renovation work – including work carried out by uninsured tradespeople or novices posing as experienced professionals.

With over 200,000 people a year attending A&E for DIY related accidents, it’s a growing concern that people are tackling major home improvement tasks themselves. As cost pressures continue to squeeze households it’s likely this trend will continue to grow, as people try their hand at DIY in a bid to help save money.*

A recent Quotezone survey found that 80% of people would attempt a household DIY job before calling in a professional, and 10% even say they’d try to tackle a full kitchen or bathroom renovation themselves.

Cost is the biggest barrier to hiring tradespeople, with 40% saying it puts them off. A further 34% said they avoid professional work because they don’t know who to trust. Interestingly, only 13% said they always hire professionals for home improvements.

Many people wrongly assume home insurance will cover most genuine accidents even if it’s caused by ‘dodgy DIY’, but in reality, a lot of policies specifically exclude damage caused by faulty or unprofessional work.

In most cases, insurers will only pay out for unforeseen events, such as storm damage or burst pipes – not problems caused by badly fitted plumbing or unsafe wiring, for example.

Failing to tell the insurer about major renovations could also be classed as a breach of the policy. That means insurers may refuse to pay a claim or even void the policy entirely. Major home improvements include jobs like rewiring, plumbing alterations, and new bathroom and kitchen fittings, if they significantly increase the home’s value or rebuild cost.

The risk is particularly high for projects that change the structure and layout of a property, or that should legally be carried out by a qualified professional under proper building regulations.

Even accidental damage cover has its limits. It often only applies to sudden and unexpected one-off incidents such as accidentally damaging the ceiling or cracking floor tiles by dropping something heavy.**

Damage caused by poor workmanship or improper installation is usually excluded from buildings and accidental damage insurance policies, meaning homeowners could be left to cover the full cost of repairs themselves if something goes wrong – which could easily run into the thousands.

Helen Rolph, home insurance expert at Quotezone.co.uk said: “It’s worrying to see that 80% are willing to try their hand at DIY projects before seeking help. Doing home improvements yourself can save money upfront, but if the work isn’t done properly or your insurer isn’t informed, it could end up costing you far more in the long run and invalidating your home insurance.

“Claims will likely be refused if damage is traced back to unsafe or undisclosed alterations – including work carried out by uninsured or underinsured tradespeople.

“Even if the original DIY job didn’t cause immediate problems, insurers could still reject a future claim if the work is later found to be the root cause.

“That’s why it’s so important to do your due diligence before hiring someone to work in your home, or before deciding to take on the job yourself to save money. If you’re hiring someone to do the work for you, don’t be afraid to ask about their liability insurance and their professional certificates – it’s also important to check for previous positive reviews, and if they’re a member of an approved trader scheme or trade association, for extra reassurance.

“If something goes wrong because of poor workmanship, or if you fail to tell your insurer about substantial work, your claim may be denied or your policy could be invalidated, leaving you unprotected.”

Eight ‘dodgy DIY’ jobs that could invalidate your home insurance in 2026:

1.Electrical rewiring or major electrical work

Any rewiring, new fuse boards or additional sockets fitted without a qualified electrician or the correct certification can be extremely dangerous. If faulty wiring later causes a fire or power failure, insurers may refuse to pay out if the work was not carried out by a certified professional or signed off under building regulations.

2.Plumbing installations

Fitting new bathrooms, showers, radiators or pipework may seem straightforward, but poor workmanship is one of the most common causes of water damage claims. If a leak, burst pipe or flood is traced back to incorrectly installed plumbing, insurers can reject the claim on the grounds of faulty workmanship.

3.Removing load bearing walls or making structural alterations

Knocking through walls, altering layouts or removing structural supports without building control approval can seriously weaken a property. If cracking, subsidence or collapse occurs later, insurers are unlikely to cover the damage if the work was unauthorised or carried out without proper sign off.

4.Loft and garage conversions or extensions

Major renovations that increase the size or value of a home must usually be declared to your insurer. Failing to do so can leave you under-insured or in breach of your policy, meaning claims linked to fire, flooding or structural defects in the new space could be refused.

5.Gas work

Any work involving boilers, cookers or gas pipework must legally be carried out by a Gas Safe registered engineer.*** If a leak, explosion or carbon monoxide incident occurs and the work was done by someone unregistered, insurers are highly likely to invalidate the claim.

6.Installing underfloor heating or new heating systems

Heating systems involve complex pipework and electrics, and poor installation can cause long term leaks, electrical faults or fire risks. If damage is traced back to an unqualified installer or uncertified work, insurers may class it as negligence and refuse cover.

7.Roof work or major window and door replacements

Replacing roofs, fitting skylights or installing new windows and doors affects both the structure and security of a home. If tiles are fitted incorrectly, water penetrates the roof, or poor-quality doors lead to a break in, insurers may argue the damage was preventable and decline the claim.

8.Poorly fitted kitchens or bathrooms

Badly sealed units and incorrectly fitted appliances can allow water to seep into walls and floors over time. Mould, rot and long-term water damage linked to substandard installation are often excluded from insurance, leaving homeowners to cover the full cost of repairs.

As a price comparison site, Quotezone helps over 4 million customers every year, compare and find savings on everything from home insurance to pet, car and travel insurance.

References:
*https://www.express.co.uk/life-style/property/2081045/diy-painting-deadly-dangers
**https://www.quotezone.co.uk/home-insurance/guides/accidental-damage-cover
***https://www.gassaferegister.co.uk/gas-safety/home-gas-safety/home-improvements/
https://www.markeluk.com/articles/what-happens-if-my-builder-isnt-insured-or-is-underinsured-and-something-goes-wrong