Our Neighbour has built their Conservatory Three Inches from our Boundary Line. Where do we stand in Respect to Building our Rear Extension Adjacent to theirs?

by: The Party Wall Surveyor


We live in a semi detached house and our neighbour is having a conservatory build. He did not consult us but we have at the moment a good relationship. We are planning to have a single storey extension built next year and have asked him that he builds his wall up to the junction line so that we can then build our wall and cut into it avoiding here being a gap between the two extensions. This was agreed with the neighbour and with his builder.

The foundations for the build have been completed and the wall has gone up however the wall is approx 3 inches back from the junction line. If we build up to the junction line there will be an unacceptable gap. Can you please advise what we can do?


I’m not sure what you mean by an ‘unacceptable gap’. Your neighbour is entitled to build anywhere on his own land, be that up to the boundary, or just back from it. Having said that I think building the wall astride the boundary would have been the best option.

As long as the designer of your extension is aware of it a 3 inch gap needn’t be a problem.