Drainage and septic tanks
What should you ask if the drain from this house joins a neighbour’s before the public sewer?
Ask your solicitor who is responsible for the shared private length, and ask the surveyor what they could actually see. A home survey does not decide ownership of a pipe and does not camera it unless agreed. A shared run can block for both houses. Responsibility is a legal and water-company question, not a condition rating.
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?
Many terraces share drains. Some lengths are public, some remain private, and the change depends on the era and the water company’s adoption, which the surveyor does not look up as a search. They may see one inspection chamber in the garden and say the onward run was not traced. Approved Document H does not identify the owner.
Your solicitor’s drainage search is the paper. The survey is the condition of what was visible. If the chamber was full of debris, that is a maintenance defect whoever owns the pipe. Get it cleaned and, if the report says so, camera the run. Do not deduct the cost of adopting a sewer. That is not a builder’s quote.
What should you ask your surveyor?
- Did you see a shared chamber, or are you guessing from the terrace?
- Was the chamber blocked, or simply not fully traced?
- Are you making any comment on who should pay?
What are the typical next steps?
- Tell your solicitor the surveyor could not trace the outfall.
- Do not agree to relay a neighbour’s drain without the search and their consent.
- If there is a blockage, price the clearance first. Relaying comes after a camera, if at all.
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 party wall award cover drains?
Not as such. Party-wall law is about walls and certain excavations. Drains are a different enquiry. Ask your solicitor which one you need.
Can a Level 2 adopt the sewer?
No. Adoption is a water-company matter. The survey cannot apply for it.