Survey repair cost calculator: roof, damp and subsidence
Pick the roof, damp or movement findings from your report for an indicative starting budget, adjusted using the tool’s house and region assumptions. The calculator can’t diagnose the cause, inspect concealed work or tell you which repair your property needs.
Last updated November 2026 · built by working UK builders
These are a builder’s 2026 figures, from someone who isn’t quoting for the job. Most cracked houses never need the underpinning one.
Need the report interpreted, not just a calculator total? In a £59 independent survey review, I’ll read your survey and photos, explain which costs are relevant and flag the questions a specialist needs to answer. You get a personal email from me and a call within 24 hours. These are realistic ranges, not fixed quotations. See the example review.
UK national averages, 2026
- New roof £8,500 Concrete-tile re-roof on a 3-bed semi, scaffold included
- Damp proof injection £3,500 Injected DPC to the ground floor of a 3-bed semi, replastering included (from ~£240 per metre)
- Underpinning £13,500 Traditional mass-concrete underpinning to one wall of a 3-bed semi
Want help turning the findings into a repair plan?
The number can change when the scope, access or cause is established. A £59 independent survey review reads the documents and photos together, adds realistic ranges to the findings and says where a specialist or contractor needs to visit. I’ve been a builder for nearly 30 years, and I write every review myself as a personal email. See what my review emails look like.
- Upload your survey or paste its link, then add your details
- Pay £59 securely. If you don’t have the file handy, choose to send it after payment
- Written review + a call within 24 hours
- Money-back guarantee if the review doesn’t give you a clear answer
“Ben was incredibly helpful. Would recommend.”
— Harry Stein, Google review
What buyers say after sending me their survey
“Ben has been absolutely fantastic. As a first time buyer getting a home buyers survey back feels like a bit of a mine field. Ben helps with approximating costs to all the points raised and also explained everything in really easy to understand terms. I feel much more confident about the property and entering negotiations with the seller. 100% worth it.”
“Fantastic service and will use again, provided comprehensive review and costs for problems identified on survey and informed discussions on potential problems arising once work starts. The service was invaluable. Ben was professional, so helpful and very knowledgeable”
“Very prompt and helpful pre-purchase service. Great to get expert advice on the survey and a realistic look at the costs involved for repairs.”
Figures are UK national averages for 2026 from published trade cost guides (FMB, MyBuilder, Checkatrade, MyJobQuote, BestBuilders), checked against what I see on real jobs. They include labour, materials, scaffold or access and making good, and are adjusted by region using standard location factors. They are not a quote. Where you pick a survey or engineer’s report, the figure is the cost of finding out, not of the repair.
Roof works: what the national average really covers
The £8,500 national average is a full strip and re-cover in concrete tiles on a 3-bed semi, with new membrane, battens and scaffold. But a survey that says the roof is “nearing the end of its serviceable life” is forecasting, not reporting a leak — concrete tiles run 40–60 years. Most roof findings in a survey are slipped tiles, tired ridge mortar or a chimney flashing: a few hundred pounds to a couple of thousand. Ask what is actually defective today. More on roof costs →
Damp: check the cause before you pay for injection
Damp proof injection averages around £240 per metre including replastering — roughly £3,500 for the ground floor of a 3-bed semi. It’s the most over-sold repair in British housing. Surveyors’ moisture meters read salts in old plaster as wet, and most “rising damp” turns out to be a leaking gutter, a path built up against the wall or failed pointing. Fix the cause first; it is often a fraction of the cost. Try the damp diagnosis tool →
Subsidence: an engineer before an underpinning quote
Traditional underpinning to one wall averages £13,500 nationally, and full elevations can run £25,000–£60,000+. But most cracks in British houses are settlement, thermal movement or a blocked drain washing out the ground — none of which need underpinning. If your survey refers you to a structural engineer, get that report before exchange, and check the house is insurable at a normal premium. Buying with past subsidence →
Using these figures with the seller
Sellers don’t move on worry; they move on a costed list. Separate what needs doing now from what’s eventual, resolve the “further investigation” items first, and ask for a specific reduction linked to specific evidence. A national average is a good sense-check — but in a negotiation, a builder’s figure for that house carries far more weight. Send me your survey and I’ll write it for you →
Frequently asked questions
How much does a new roof cost in the UK?
The UK national average for a concrete-tile re-roof on a 3-bed semi is around £8,500, within a typical range of £6,500 to £10,500 including scaffold. A 2-bed terrace is nearer £4,500 to £7,500 and a 4-bed detached £10,000 to £17,000. Natural slate or clay costs roughly 60–70% more. Most survey roof findings are not a new roof at all — slipped tiles and a re-bedded ridge are usually a few hundred pounds.
How much does damp proof injection cost?
Injected chemical DPC costs from around £240 per metre including hacking off and replastering, so one 5m wall is roughly £1,000 to £2,000 and the ground floor of a 3-bed semi around £2,500 to £5,000 (national average about £3,500). Before paying for it, make sure the cause isn’t a gutter, a raised path or failed pointing — those fixes are far cheaper and true rising damp is much rarer than surveys suggest.
How much does underpinning cost?
The UK national average for traditional underpinning to one wall is around £13,500. Mass concrete runs about £1,500 per m² and mini-piling around £2,600 per m², so one wall or corner of a 3-bed semi is typically £13,500 to £23,500. Resin injection, where the ground suits it, is usually cheaper. A structural engineer’s report (£500–£1,500) always comes first, and most cracked houses never need underpinning at all.
Are these figures a quote?
No. They are national average ranges for 2026, adjusted for your region and house size. Your actual cost depends on access, the exact extent of the defect and what the surveyor could not see. Send your survey for a £59 builder review and Ben will give realistic cost ranges from your report and explain what needs checking on site, within 24 hours.
Should I renegotiate or walk away?
Renegotiate when the problem is knowable and finite — a roof, damp with an obvious cause, a stable historic crack. Walk away when it is open-ended: movement with no agreed cause, or an engineer who will not commit. The test is whether someone can put a number on it.