Chimneys and parapets
Two fires in neighbouring houses are said to share one flue. Have both connections been traced?
Both connections have not been traced. A claim that two fires in neighbouring houses share one flue is a story about the route, not a survey that followed both appliances into the stack. This visit could see only what was open on this side. It did not enter next door, did not smoke-test the flue and did not confirm a shared gathering. Sharing a flue can be a serious combustion risk if it is true. The survey has not decided that the fires do share, or that they do not.
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 flue should carry products from the appliance it serves. If two fires truly join one flue, fumes from one house can be pushed toward the other when pressures change. Tracing that means following each connection, the gathering and the stack, including the neighbour's side. None of that second connection was opened. A remark from an owner, or a similar fireplace on a party wall, is not a traced route. The survey recorded the claim and the limit of access.
Ask the solicitor to put the shared-flue claim to the seller and to the neighbour's side if the papers allow. A chimney specialist can test and trace flues when instructed, including any need to enter next door with permission. That test is not this report. Tell a lender the installation was not proved shared and was not proved separate. Do not let a verbal claim stand as a completed flue investigation.
What should you ask your surveyor?
- Were both fire connections followed into the stack, or only this side seen?
- Did anyone smoke-test or camera the flue on this visit?
- Was next door's loft or fireplace entered so the gathering could be seen?
What are the typical next steps?
- Treat the shared flue as a claim, not as a traced route.
- Ask the solicitor to put the claim to the seller in writing.
- Instruct a chimney specialist if both connections must be followed.
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 one open fireplace prove the neighbour uses the same flue?
No. An open fire on this side shows only this appliance and the flue you could see. The neighbour's fire, register and any joining of the passages sit beyond a wall that was not opened. Similar chimneypieces are not a shared flue. The survey has not joined the two fires together and has not separated them either.
Can this instruction include going into the neighbouring house?
Not unless that access was agreed and actually given. A home survey of this house stops at this house. Next door was not entered, so their connection stays off the plan. If a specialist needs that side, the solicitor has to seek permission. The report cannot pretend the neighbour's flue was inspected.