My buyer's survey flagged subsidence. What happens now?

The word appears in a paragraph near the end of the report, often alongside phrases like further investigation recommended. Your buyer reads it, goes quiet, and then comes back asking what you are going to do about it.

Take a breath. A general surveyor is not a structural engineer, and their job at this point is to flag anything that might need a closer look. Flagging it is the system working, not the sale ending.

What is subsidence, and what did the surveyor actually see?

Subsidence is the downward movement of a building's foundations caused by a change in the ground supporting them. It is not the same as settlement, which is the small, expected movement of a new or newly extended building as it beds in.

RICS guidance points to three usual causes. Around 70 per cent of cases come from tree roots drawing moisture out of clay soil, which shrinks as it dries. Leaking drains and water pipes account for many of the rest, by washing away or softening the ground under a foundation.

What a surveyor typically sees is cracking. RICS treats unexplained cracks wider than 3mm as the point at which specialist help is worth getting, particularly where they run diagonally in a stepped pattern through brickwork, are wider at one end, and appear near windows or doors.

Does this mean my house needs underpinning?

Almost certainly not. RICS puts the figure at fewer than 5 per cent of affected properties, and the Institution of Structural Engineers treats underpinning as a last resort rather than a default repair.

The far more common outcome is monitoring. Cracks are measured and watched, often over a full 12 months, to establish whether anything is still moving. Where a tree is the cause, managing or removing that tree can settle the ground on its own.

What should I do first?

Work in order. The single most expensive mistake here is negotiating a price before anyone knows what is actually wrong.

1. 1. Read the report yourself, in full

   Ask your buyer or their surveyor for the relevant pages. Note the exact wording, because a report saying evidence of historic movement, no evidence of recent progression describes a very different property from one recommending urgent structural investigation.

2. 2. Check your own paperwork before you say anything

   Look for previous surveys, structural reports, guarantees, or an insurance claim history on the property. If a past owner had the movement investigated and signed off, that paperwork is worth more to your sale than any argument you can make.

3. 3. Speak to your buildings insurer

   Subsidence is covered by standard UK buildings insurance. Tell your insurer what has been flagged and ask what a claim would involve, and be clear that a claim will attach to the property's history.

4. 4. Commission a specialist report

   A structural engineer's opinion is the document that ends the argument in either direction. It is what turns a maybe into a fact, and either party can pay for it.

5. 5. Ask about a tree before you ask about foundations

   If there is a mature tree close to the affected corner of the house, say so early. A tree-related cause is the most common and often the most manageable.

6. 6. Only then discuss money

   Once you know the cause and the likely cost, you can weigh a reduction against the actual repair. Agreeing a figure before that point means guessing, and sellers who guess in this situation usually guess against themselves.

What is normal here, and what is a red flag?

Some caution from your buyer is fair. Insurers paid an average subsidence claim of £20,000 in the second quarter of 2026, a record, and domestic subsidence payouts reached £307 million across 2025, the highest annual figure the Association of British Insurers has recorded. Hot, dry summers are the reason, and buyers read the same headlines you do.

Will this cost me the sale?

It might cost you this buyer, and it does not have to. Survey findings are the second largest cause of failed sales in Britain: Quick Move Now found 27 per cent of failed transactions in the second quarter of 2026 collapsed at the survey stage, behind mortgage and lending problems at 33 per cent.

The way to protect yourself is to make the property's position knowable rather than arguable. A structural report and a clean insurance history travel with the house, so if this buyer walks, the next one starts from evidence rather than from a scary word in a report.

Once you have a specialist report, you are no longer negotiating against a fear. You are negotiating against a number.

How do I keep control while this is sorted out?

• Judge your buyer's commitment by what they have spent and instructed, not by what they say. A solicitor instructed, a mortgage application submitted and searches ordered are real. Words are not.
• Keep your own solicitor moving, because that costs little and protects your timeline if this buyer proceeds.
• Hold off the larger irreversible spends until the structural position is known and your buyer has confirmed they are continuing.
• Ask your agent to keep the listing visible rather than fully withdrawn until the report is in and the buyer has recommitted.
• Put every offer and counter-offer in writing so the sequence is not remembered differently in three weeks.

Common questions about subsidence and selling

ValuQ gives UK homeowners free, side-by-side property valuations from competing local estate agents. Where a property has a history a buyer will ask about, seeing several agents set out how they would price and position it, before you speak to any of them, is how the decision stays yours.