Originally I had a garage that was built as a detached building. It was joined to the neighbour’s identical garage when the properties were built in 1961, so essentially 2 garages side by side with a 4 inch wall dividing the two. My roof had become unsound and I decided to replace the whole garage ( with full planning consent ). demolished my side, leaving the dividing wall and made repair to the roof on my neighbours side as it was cut and exposed.
My new garage was built 4 inches away from the old dividing wall thus 4 inches into my boundary. Two years later my neighbour has replaced the roof on their side and extended the length of the garage . But now their new roof is finished less than one inch from the edge of my garage, therefore over the centre line of the old existing dividing wall by half the thickness of the old dividing wall and taken up 3 inches of the 4 inch gap I had moved my garage in by. The length of their new garage is now over 24 feet . my original fence now looks like it sits 5 inches into there land , I am concerned that change of hands of mine or their property could prove contentious if the new owners dont know where the true dividing line is.
This is now a boundary issue rather than a party wall matter and not therefore something that we cover on www.partywalladvice.com. Removing your garage and changing the original dividing wall to an external wall would have come within the scope of the Party Wall Act and you should have served notice on your neighbour before doing that work – as it is now complete that is no longer an issue.
Your neighbour’s overhanging roof is a simple matter of encroachment. If your neighbour refuses to cut their roof back so that it is within their boundary your only option would be to take them to court although there is a possibility that the courts will say that 3 inches is too small a trespass to make a ruling on.