Neighbours side extension overhangs my property

[Guest]

We bought our house with planning permission to build a side extension. *Our neighbours are against this being built and will be asking for party wall agreements etc. However they built a side extension with attaches to our bourse and the window seal and gutter hangs over my property, so in order to build my extension we would be interfering with their old building. I believe they build their glass extension many years ago and do not have permission, however I am not sure we’re we stand with theirs interfering with us. *To add they do not like anyone, they hate any sort of home improvements and will do anything in their power to stop you enjoying your home. *Please help!

[MIKE770]

have you approached planning department for info on their application if one (sounds it might not have permissions) & if over hangs yours they have a problem no doubt??* other probably advise on here soon?
*

[des8]

How is your extension to be built?
On the boundary with your neighbour does it make use of an existing building, or will it be a new wall built upto but not on the boundary line?
If the latter it is not a party wall for the purposes of the act.
Will it be built of a strip foundation (in which case you may be encroaching on your neighbour's land) or off a raft?

Their extension sounds more like a conservatory and could have been erected under permitted development rules and not needed PP.
However their rain water goods seem to be trespassing so find out when it was put up before trying to have them removed as there might possibly be a prescriptive easement.