Survey repair cost calculator
Surveys tell you what is wrong and almost never what it costs. Tick what yours found and get a builder's figure, split by what genuinely needs doing now.
Last updated July 2026 · built by working UK builders
Ranges assume a competent VAT-registered contractor and typical UK access. Add roughly 25% for central London and deduct around 10% for the north of England, Wales and Northern Ireland. Where a finding says "further investigation", the figure shown is the cost of the investigation, not the repair.
How to use this in a negotiation
Sellers do not respond to worry. They respond to a schedule. The approach that works, in order:
- Separate the urgent from the eventual. A roof at the end of its life in eight years is not the same as a leaking valley. Sellers know the difference and will stop listening if you bundle them.
- Resolve the "further investigation" items first. An engineer's report or a drain survey costs a few hundred pounds and converts your biggest unknown into a figure. It also makes everything else you say more credible.
- Put it in writing as a costed list. Item, evidence, cost, source. One page. Through the agent, politely.
- Ask for a specific number. "We would like to proceed at £X, reflecting the £Y of immediate work identified in the survey" beats "we're worried about the roof".
- Decide your walk-away before you start. And do not reveal it.
What sellers will and will not accept
Usually accepted: defects the seller did not know about, anything that affects mortgageability, and work that is genuinely urgent and evidenced by a professional.
Usually rejected: the kitchen being dated, single glazing, general decoration, and anything that was visible on the day you offered. The price already reflected those, and the seller knows it.
The findings buyers most often misread
"The roof covering is at the end of its serviceable life"
An estimate of remaining life, not a statement that it leaks. Concrete tiles run 40–60 years. Ask what is actually defective today.
"Rising damp was indicated by the moisture meter"
Moisture meters measure electrical conductivity, and salts in old plaster conduct beautifully. True rising damp is far rarer than reports suggest. Establish whether the ground level, gutter or pointing is the real cause before you buy an injected DPC.
"Further investigation is recommended"
The surveyor is telling you they could not see enough. It is not a defect and it is not a clean bill of health — it is a task list, and it should be completed before exchange.
"The electrical installation appears dated"
Surveyors do not test electrics. Get an EICR. A satisfactory report with C3 items is a normal installation, not a rewire.
When to walk away
Structural movement with no agreed cause. Dry rot of unknown extent. A property where the insurance history includes a subsidence claim and the current insurer will not confirm cover. Japanese knotweed with no treatment plan and a lender who has already flinched. In each case the problem is not the cost — it is that nobody can tell you the cost.
Frequently asked questions
How much can I knock off after a bad survey?
There is no formula. What moves a seller is a specific, evidenced schedule of urgent work with real costs attached — not a percentage. In practice, buyers who present a costed list of genuine defects typically achieve somewhere between half and all of the urgent repair figure, and almost nothing for cosmetic or end-of-life items the price already reflected.
Should I renegotiate or walk away?
Renegotiate when the problems are knowable and finite — a roof, a rewire, a boiler, drains. Walk away when they are open-ended: unresolved structural movement, dry rot of unknown extent, or a property where every investigation reveals another one. The test is whether you can put a number on it.
My survey says "further investigation is required". What do I do?
Do the investigation before you exchange, not after. A structural engineer’s report, a CCTV drain survey, an EICR or a damp specialist’s inspection each cost a few hundred pounds and turn an unbounded risk into a number. Surveyors write that phrase precisely because they could not see enough to price it.
Does the seller have to fix anything?
No. Property in England, Wales and Northern Ireland is sold as seen, and the seller has no obligation to repair or reduce. Your leverage is entirely commercial: how much they want to sell, how far along the chain is, and how credible your figures are.
Are these costs what a builder would actually charge?
They are realistic 2026 ranges for a competent, insured contractor across the UK, with the usual regional variation. They are deliberately shown as ranges because that is how building work prices. For a specific property, a builder looking at your photos and survey will get much closer than any calculator can.