Age and type of house
A shop extractor duct passes through the floor of the flat. What has the flat survey not tested about that duct?
It has not tested the fan, the duct or the fire separation around it. A shop extractor that passes through the floor of the flat shows, at most, a grille or a boxed duct in the rooms. Grease, smell or a noisy fan can be noted. The motor was not electrically tested, and the duct inside the floor void was not opened. A flat inspection does not take in the shop below. Services are visual only, not safety-tested.
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?
Extractor ducts from a shop can run in a bulkhead, through a floor void, or up a shaft the flat only meets at one boxing. The surveyor sees the boxing, any greasy stain, any gap at the ceiling, and whether the fan is audible. They do not switchboard-test the motor, do not measure airflow and do not open the void to see fire stopping around the duct. Standard inspection does not remove secured panels. A flat instruction is not a tour of the shop kitchen, so the canopy and the filters downstairs stay outside the visit.
Do not treat a quiet day as a test, and do not assume the duct is fire-stopped because the boxing is painted. If you need the void opened, that is a further visit with permission. The survey of the flat also does not decide who must clean or repair a shared duct. That is a lease question for your solicitor. Condition, if any was visible, stays in the report. An untested fan should be described as untested, not as safe and not as failed, unless something the eye could see already shows a defect.
What should you ask your surveyor?
- What of the duct was visible inside the flat, and what stayed inside the floor?
- Did you test the fan electrically, or only see or hear it?
- Was the shop kitchen entered, or is the lower end of the duct outside this inspection?
What are the typical next steps?
- Do not describe the duct as fire-stopped.
- Ask your solicitor who maintains a duct that serves the shop.
- If grease or a gap worries you, ask for the boxing to be opened on a further visit.
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 grille mean the duct through the floor was inspected?
No. A grille is the room face. The void and the shop end were not tested.
Are services in a flat safety-tested on a home survey?
No. They are visual only. A fan that runs, or does not, is not an electrical certificate.