Basements and cellars
The survey could see leaves covering the lightwell grille. Is that a failed drain design?
No. Leaves on the grille are what was there on the day, and they can stop water passing so the lightwell holds water against the window. They do not describe how the drain was designed or whether the pipe beyond the grille is broken, and the survey did not rod that pipe.
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 lightwell is a hole against the wall. The grille is the cover you can see. A home survey can photograph leaves and a rusty frame. Approved Document H is the building-regulations document for drainage, and the inspection does not apply it as a certificate. Clearing the leaves would show the grille. It would still not prove the underground run.
If the inside of the window is stained, keep that stain with this observation without upgrading it into a designed failure. Ask a drainage firm, if you need more, to look at this outlet rather than only at a kitchen stack. Do not hose the leaves away before you have a photograph. A dry lightwell after someone has swept it is a different day from the one the survey recorded.
What should you ask your surveyor?
- Did you see leaves on the grille, water in the well, or both?
- Could you see past the leaves to an outlet, or was it covered?
- Are you claiming the pipe is broken, or only that the grille was blocked?
What are the typical next steps?
- Photograph the grille before anyone sweeps it.
- Do not treat a swept grille as a camera survey of the drain.
- If water has entered, ask a drainage firm about this outlet. Do not stop at new glass.
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 grille itself a drainage design the survey can approve?
No. The survey saw a cover and the leaves on it. It did not design the well and it did not test the pipe.
Does a blocked grille prove rising damp inside?
No. Water held in the well is water from outside at that window. It is not a diagnosis of the damp-proof course.