Subsidence, settlement and heave
Does a crack where a conservatory meets the house mean the main house is subsiding?
Not by itself. Conservatories often move differently from the house because they are lighter, differently founded, or simply bolted on. A crack or a gap at the junction can be that joint. Subsidence, in the Association of British Insurers’ words, is the ground moving down and taking the building with it. The home survey should say whether the crack is in the house wall or only at the add-on.
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?
Look at the house corners away from the conservatory before you rename the junction. A gap in a silicone joint, a leaning conservatory frame, or a door that no longer meets the house is often the conservatory. A crack that runs through the brick of the main wall, especially with other cracks, is the house. The survey cannot see the foundations of either on a standard visit.
Planning and building-regulations papers for the conservatory are the solicitor’s question. They do not explain the crack. There is no RICS price for taking a conservatory down or for underpinning the house. Do not demolish it on a viewing to “see the wall”. Ask the surveyor which structure the sentence is about.
What should you ask your surveyor?
- Is the crack in the house masonry, or in the junction?
- Are there matching cracks elsewhere on the house?
- Could you see how the conservatory is attached?
What are the typical next steps?
- Do not describe a silicone gap as subsidence in a price demand.
- If the house wall is cracked, investigate that, not the conservatory glazing.
- Ask the solicitor for the conservatory papers separately from the crack.
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 a lean-to garage the same kind of junction?
It can be. A different structure on a different base can crack at the joint. Say which building is moving.
Does a conservatory roof leak count as subsidence?
No. A leak at the flashing is water. It is not the ground going down.