Radon
A pipe and fan that look like a radon sump are in the cellar. Has the survey measured the radon level, or only seen the hardware?
The survey has only seen the hardware. A pipe and fan that look like a radon sump are in the cellar, and no radon level was measured. The visit did not test the air, did not confirm that the fan runs, and did not sample anything. UK radon mapping is a separate product from a note that a pipe is there. The survey can describe the equipment it saw. It cannot say the level is high, low or acceptable, because that measurement was not made.
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?
A radon sump is a void under the floor, with a pipe and often a fan, intended to draw soil gas away before it enters the rooms. In a cellar the surveyor may see the pipe and the fan and little else. Looks like is the right caution. The kit does not tell you the level in the air, and a stopped fan would not announce itself unless someone checks it. The home survey has not made that check and has not measured the gas.
UK radon services explain measurement as its own step, using detectors over a period, not a glance at a pipe. If you want a level, instruct that measurement. A lender may ask about radon in some areas. Point them to a result if you obtain one, not to this survey. Tell the solicitor the house appears to have sump hardware and that no test result was in the survey. Do not let a seller's remark about the fan stand in for a reading.
What should you ask your surveyor?
- Did you only see the pipe and fan, without an air test?
- Was the fan running, or was even that left unconfirmed?
- Have you kept map information separate from this cellar note?
What are the typical next steps?
- Record the cellar pipe and fan as hardware only.
- Do not treat the survey as a radon measurement.
- Instruct a proper radon test if you need a level.
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
If someone switches the fan on, does that create a radon result?
No. A running fan shows a motor responded. It does not sample the air and it does not produce a radon level. The survey, even with a fan heard, would still only have seen hardware. Measurement is a different exercise.
Does the pipe mean the house sits in a higher-radon area?
Not by itself. People fit sumps for more than one reason, and the survey has not checked a map as part of naming this pipe. Area information is a separate lookup. The cellar note stays a description of equipment, not a map result.