Guide · 12 min read

Property red flags:
what to watch out for

The issues estate agents won't volunteer, the risks not on the listing, and the problems that turn into nightmares after you've exchanged.

A property listing tells you what the seller wants you to see. It doesn't mention the flood risk, the refused planning application next door, or the EPC rating that implies £6,000 annual energy bills. Here are the most common red flags OfferHound surfaces — ranked by severity.

🔴 High severity — potential deal-breakers

Critical

Flood Zone 2 or 3

Properties in Flood Zone 2 (medium risk, 0.1–1% annual probability) or Zone 3 (high risk, 1%+) face materially higher insurance costs, potential mortgage difficulties, and real risk of flooding. Check the Environment Agency map before offering. This doesn't mean don't buy — but it significantly affects price and what you'd need to spend on mitigation.

Critical

Subsidence history

Evidence of subsidence — cracked or bowing walls, sticking doors and windows, diagonal cracks from window corners — can indicate a serious structural problem. Check with insurers, order a full structural survey, and get written disclosure from the seller about any previous claims.

Critical

Short lease (under 80 years)

On leasehold flats, a remaining lease under 80 years triggers "marriage value" in lease extension negotiations, making it dramatically more expensive. Under 70 years, many mortgage lenders won't lend. Check the lease length before you get emotionally invested.

Critical

High service charge on leasehold

Leasehold properties carry annual service charges that can range from £500 to £10,000+ per year. Always ask for 3 years of service charge accounts and enquire about any planned major works. Some buyers are shocked to find a £15,000 major works bill arriving within a year of completion.

🟡 Medium severity — require investigation

Investigate

Refused planning applications

A refused application for an extension or outbuilding limits your future development options. Check the planning portal for any refusals. This is a legitimate negotiating point — if similar properties have approved extensions, the lack of permission (and cost to achieve it) is reflected in price.

Investigate

Poor EPC rating (E, F, G)

A very poor energy rating means high running costs and potentially significant upgrade costs. Future regulations may require C or above for mortgage lending. Factor the cost of works into your offer.

Investigate

Nearby development proposals

Check the local planning portal for applications within 200m. A proposed block of flats that would overlook your garden, or a commercial development that would increase traffic — neither appears on the listing but both materially affect value.

Investigate

Multiple previous sales in short period

If a property has sold twice in the last 3 years, there may be an undisclosed issue that drove previous buyers to sell. Ask why, and check if there are any known issues with the building or area.

🟤 Lower severity — factor into offer

Note

Dated kitchen and bathrooms

Cosmetic work that you'll need to do. Quantify the cost (typical kitchen refurbishment at this price point: £8,000–£25,000) and include in your offer justification.

Note

Long time on market with no reduction

Signals seller stubbornness, not necessarily a problem with the property. Use as negotiating leverage — they've had their chance at the asking price.

OfferHound surfaces all of this automatically — flood zone, planning history, EPC issues, and comparable time-on-market data — before you make an offer. £9.99.

Find the flags before you offer

Most listings don't advertise their risks. OfferHound checks 12 official sources and surfaces every flag before you commit.

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