Property red flags that could cost buyers over £50k
04/03/2026
Homebuyers are being warned not to overlook property red flags which could result in unexpected costs of up to £53,000.
Home insurance experts from Quotezone.co.uk have highlighted eight red flags buyers should look out for as the UK housing market nears its most competitive period.
Purchasing a property is one of the most significant financial decisions in a person’s life and spotting issues early can save buyers thousands of pounds down the line.
Given over a third of house sales in January were to first-time buyers, it’s vital those new to the property ladder know what to watch out for.* Issues like signs of structural damage, plumbing problems indicated by weak water pressure, or a property with a poor energy performance certificate (EPC) could be caught during a viewing.
Red flags that can come to light after an initial viewing include properties with leased solar panels, which some lenders are cautious about, and properties that have had unauthorised renovation work.
February and March are the best months of the year for properties to sell. But this also means buyers face increased competition, making it more important than ever to spot potential issues and not feel pressured into committing to a purchase out of fear of missing out.**
Helen Rolph, home insurance expert at Quotezone said: “Over the next couple of months, the housing market becomes more competitive and this can put pressure on buyers to move quickly to secure their ideal home.
“But a dream house can quickly become an expensive nightmare if buyers are rushed into a purchase without fully researching the risks and implications of underlying issues.
“Spotting potential red flags early on can save thousands of pounds and a lot of stress. It’s critical that buyers take the time to carry out thorough viewings at different times of the day, be prepared to ask difficult questions, and do their homework on the local area before progressing to professional surveys and examining legal details.
“The current owners must legally tell potential buyers any existing issues they are aware of with the property – failure to notify the new buyers could result in financial penalties, claims for compensation or even legal action.
“It’s also important that home insurance is in place as early as signing the contract, this ensures buyers are more likely to be covered for incidents in the build-up to completion and covers the high risk of damage on moving day itself.”
Eight red flags for homebuyers that could cost thousands:
Structural issues
Cracks in walls, uneven floors, and evidence of subsidence can point to underlying foundation problems, with average costs of £10,000 to fix. Problems in the roof like cracked tiles or blocked guttering can also be costly, with average costs of £7,000 to replace a roof in the UK.
Retrospective planning permission
You will need to know whether planning permission was obtained for any extensions, conversions or alterations to a property. After purchase, you become liable for the property and any previous unauthorised works, and if you receive an enforcement notice from the local authority, retrospective planning permission costs upwards of £258, or you may need to undo the unauthorised works.
Leased solar panels
‘Rent-a-roof’ solar panel schemes in the 2010s saw many homeowners install solar panels for free by a third-party company in exchange for leasing their roof space for 20-25 years. Some lenders can be cautious about homes with leased panels, and buyers should ensure they thoroughly check the lease agreement and any potential maintenance costs before purchasing.
Electrical issues
Old and deteriorating wiring is not only inefficient, but also poses a significant fire hazard. The average cost to rewire a 3-bedroom house is £4,450 – £8,000 depending on location, fittings, and the complexity of the job, so buyers should be aware of potential bills they may face after purchase.
Plumbing problems
Buyers should test the toilet flush and run all taps and showers to check for issues such as low water pressure, slow drainage, gurgling water or strange odours. These issues can often point to bigger underlying problems with the plumbing. If completely new plumbing needs installed, the average cost of installation in a 3-bed property is £19,000.
Damp and mould
Damp and mould are some of the biggest property red flags for buyers and can indicate a host of other underlying issues such as poor ventilation or broken guttering. The average cost of damp proofing a property is £5,000. As well as being costly, leaving it untreated could pose significant health risks.
Poor energy ratings
Houses in the UK with a poor energy performance certificate (EPC) – typically E, F, or G – should be a red flag for buyers. It indicates a property could have poor insulation and outdated systems. It also results in higher energy bills, with an average difference of almost £4,500 in yearly energy costs between an EPC A and EPC G rated 3-bed semi-detached property.
Empty adjacent land
Those sprawling, uninterrupted field views behind your dream home may look appealing now, but it’s important to check local area plans to see if there is local development work in the pipeline. Unobstructed views and privacy can quickly disappear, with building work bringing noise and traffic which can have impacts on future house value and resale. Homeowners are not entitled to a view, meaning little can be done to prohibit developments, so it’s essential research is done beforehand.***
Quotezone helps over four million customers every year to compare and find savings on all sorts of home essentials, such as home emergency cover and nonstandard home insurance.
References:
*https://www.independent.co.uk/money/south-east-britain-david-hollingworth-london-south-west-b2916724.html
**https://www.rightmove.co.uk/press-centre/february-march-are-the-best-months-to-list-a-home-for-sale/
*** https://www.milnerslaw.co.uk/do-homeowners-have-a-right-to-a-nice-view/
| PROPERTY RED FLAGS | POTENTIAL COSTS |
| Structural issues | £10,000 |
| Retrospective planning permission | £258 |
| Replacing a roof | £7,000 |
| Electrical issues | £4,450 – £8,000 |
| Plumbing problems | £19,000 |
| Damp and mould | £5,000 |
| Poor energy ratings | £4,500 |
| Total Potential Cost | £53,758 |
Table references:
Subsidence -https://www.myjobquote.co.uk/costs/fix-subsidence-cost
Roof – https://www.checkatrade.com/blog/cost-guides/roof-replacement-cost/
Planning permission -https://hoa.org.uk/advice/guides-for-homeowners/i-am-improving/cost-of-planning-permission/
Rewiring – https://www.checkatrade.com/blog/cost-guides/rewire-house-cost/
Plumbing – https://www.checkatrade.com/blog/cost-guides/plumbing-installation-costs/
Damp proof – https://www.checkatrade.com/blog/cost-guides/damp-proofing-cost/
Energy differences – https://www.rightmove.co.uk/guides/energy-efficiency/energy-bills/average-uk-energy-bills-how-to-save-money/