Not all survey findings are equal. Some defects are minor and easily fixed — others are serious enough to make you walk away. Here's how to identify the genuine red flags and what to do about them.
What it is: Subsidence is the downward movement of the ground beneath the property. Heave is the upward movement. Both can cause serious structural damage.
Signs in the report: Diagonal cracks at corners of windows and doors; stepped cracking in brickwork; doors and windows sticking asymmetrically.
⚠️ Repair cost: £5,000–£50,000+. May affect mortgage and home insurance availability. Always get a structural engineer's report before proceeding.
What it is: Serious faults in load-bearing walls, roof structure, lintels, or floor joists that compromise the integrity of the building.
Signs in the report: Bowed or bulging walls; sagging roof ridge or purlins; inadequate or missing lintels; rotten floor joists.
⚠️ Repair cost: £2,000–£30,000+. Commission a structural engineer's report and get detailed contractor quotes before renegotiating.
What it is: An invasive plant whose roots can penetrate foundations, drains, and walls. It's extremely difficult and expensive to eradicate.
Signs in the report: Plant identified in garden or adjacent land; RICS now has a zoning system (Category 1–4) based on proximity and impact.
⚠️ Repair cost: £2,000–£15,000+ for professional treatment (typically 5-year programme). Many lenders refuse to lend without a professional management plan in place.
What it is: Failing or missing slates/tiles, deteriorated flashings, damaged or absent felt underlay, or end-of-life flat roofing requiring complete replacement.
Signs in the report: Water ingress stains internally; visible gaps or slipped tiles externally; sagging gutters; aged lead flashings.
⚠️ Repair cost: £3,000–£20,000+ for a full re-roof. Partial repairs can be £500–£3,000. Get a specialist roofing contractor's assessment.
What it is: Moisture rising from the ground through walls (rising damp) or entering through the external envelope (penetrating damp). Can cause structural timber decay if left untreated.
Signs in the report: High moisture meter readings; tide marks on walls; peeling plaster; efflorescence (white salt deposits) on brickwork.
⚠️ Repair cost: £1,000–£8,000+ depending on extent. Always get a damp specialist (not just the surveyor's reading) to confirm cause before treatment.
What it is: Old wiring (aluminium, rubber-sheathed, or obsolete consumer units), lack of RCD protection, or inadequate circuits for modern use.
⚠️ Repair cost: £3,000–£10,000 for a full rewire. Commission an Electrical Installation Condition Report (EICR) from a Part P electrician.
What it is: Properties built before 2000 may contain asbestos in textured coatings (Artex), floor tiles, roof sheets, or pipe lagging. Undisturbed asbestos isn't immediately dangerous but removal is costly.
⚠️ Repair/management cost: £500–£5,000+ depending on extent and location. Get an asbestos survey if suspected.
What it is: Collapsed, cracked or root-invaded drains; inadequate soakaway; shared drains with no legal agreement; septic tank requiring replacement.
⚠️ Repair cost: £1,000–£10,000+. A CCTV drain survey (£200–£400) will confirm the extent. Essential for older properties.
What it is: Flat roofs (common on extensions and some older properties) have a typical lifespan of 10–20 years. An ageing flat roof will need replacement and may cause water ingress.
⚠️ Repair cost: £1,500–£8,000 for a full flat roof replacement. Some lenders are cautious about properties with large areas of flat roof.
What it is: Prefabricated concrete (PRC), steel frame, timber frame, or system-built properties that many lenders class as "non-standard" and may refuse to mortgage or require a specialist report on.
⚠️ Mortgage risk: Some PRC properties require a Designated Approved Inspector certificate before lenders will lend. Check before proceeding.
Walking away is the right decision when:
Remember: In England and Wales, you can legally withdraw at any time before exchange of contracts without penalty — though you will lose any survey and solicitor fees paid. Don't let sunk costs pressure you into a property that will cause you financial or practical hardship.