Listed buildings and conservation areas
Should a survey of a listed house separate the original fabric from a modern rear extension?
Yes, in the way it describes condition. Historic England explains that listing covers the building, not a single front, and a modern rear extension can still stand on a listed house. The survey should describe the older fabric and the extension separately, and it does not decide whether the extension was consented.
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?
The practical reason is that the defects differ. Old brick and a new cavity wall do not take the same water, and a flat roof on the extension is not the pitched roof on the original house. If the report uses one construction line for both, ask for it to be split. A home survey does not apply for listed building consent and does not tell you the extension is lawful or unlawful.
Your solicitor asks what consents exist. The surveyor tells you whether the junction is cracked, whether the new roof holds water, and what they could not see. Do not invent an outcome. Absence of a letter in the kitchen drawer is not proof the work was refused, and a consent is not proof the walls are dry. Keep the condition notes and the papers in separate piles.
What should you ask your surveyor?
- Which parts do you think are original, and which are the later extension?
- What did you see at the junction?
- Are you deciding consent?
What are the typical next steps?
- Ask the survey to split the description if the extension was written up as the old house.
- Ask the solicitor about consents. Do not ask the survey to file them.
- Do not assume the extension is unlisted because it looks new.
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
Does a new kitchen in the old part count as the extension?
No. Fittings in an old room are not the rear extension. Ask the survey which walls and roofs it means.
Will the surveyor tell you the extension was allowed?
No. They describe fabric. Consent is not a condition rating.