Subsidence, settlement and heave

How can heave lift a building when subsidence drops it?

Subsidence is the ground going down under the building, so part of the house drops. Heave is the ground swelling, often when a clay soil takes on water after a tree is removed, so part of the house is pushed up. The crack patterns can look similar on one visit. The history of the trees is part of the evidence.

Last reviewed 24 October 2026. Written for buyers in England and Wales unless this answer says otherwise. No named surveyor has signed this page. It is general guidance, not a report on your house, and not legal advice.

What is the fuller explanation?

Clay shrinks in dry weather and swells when it rewets. A large tree can hold a clay soil drier than the soil further away. Cut the tree down, and that soil can swell for a long time. A surveyor who was not given that history cannot distinguish heave from subsidence by staring at one crack. The ABI’s subsidence pages describe downward movement and the claims process for people who already own and insure the house. They do not publish a test a buyer can do in an afternoon.

Do not remove a mature tree before exchange to “stop the risk”. You may start the very swelling the next owner will inherit. Ask the surveyor what the tree and the soil would mean for further investigation, and ask your solicitor what the tree preservation or conservation rules are before anyone talks about felling.

What should you ask your surveyor?

Are you describing downward movement, upward movement, or a crack you cannot yet assign?
What do you know about trees removed on this site?
Would a drain test or a soil investigation be the useful next step, or monitoring?

What are the typical next steps?

Ask the seller, in writing, whether trees have been removed and when.
Do not fell a tree as a pre-exchange repair.
If the lender asks for a structural report, give that engineer the tree history. Do not make them start from the crack alone.

Costs vary with the building and with who you instruct. Where this page does not cite a published figure, ask the surveyor, a relevant specialist, or your solicitor for a written quote. Do not treat a forum average as the price.

Also asked about this

Is heave covered by the same insurance conversation as subsidence?

Insurers treat ground movement in their own policy wording. The ABI explains subsidence for homeowners. Read the policy you are being offered. The survey is not an insurance certificate.

Can a new soakaway cause heave?

Changing where water goes into clay can move a building. The survey has not tested that. Tell the investigator if you know the drainage has changed.