boundary wall & putting a shed there

I think she may already be in the wrong for building the wall right on the boundary as this means the footings must be on your land. (We have a six inch gap where we built as near as possible to our boundary, planning wouldn't allow it nearer.) You need to check with your local planning department but may mean you can use this as gentle leverage to persuade her to put the vent elsewhere.
And of course you need to advise her (very nicely of course) that you will be asking a planing inspector to call to give you advise on your proposed extension.
As jeanie says you need to tread carefully.

Move carefully on this one, if you sell in the future any disputes with neighbours have to be documented on legal forms and this could put buyers off.

Firstly get along to your planing department and have a look at the plans for this extension.

I can't think that you would not have been informed by planning if your neighbour was building up to the boundary. Ask the planning department about vents being installed on boundary walls.

Who owns the wall? If it forms a boundary I would assume the rules are the same as fencing. My right hand boundary belongs to my neighbour the left hand is ours. If it's your wall then she has no right to the vent surely.

Check the online planning portal - it will tell you everything you need to know

Did your neighbour get planning permission to build up to the boundary, or building regulation approval?
I know the rules are changing now, but I'm sure she will still need building regs for putting foundations in next to your boundary.

I think you will find that your neighbour is in the wrong, so you have the moral high ground. They should not have put the vent onto your property. Whether you can get that over to an aggressive neighbour is another matter - it is possible, of course, that she is being aggressive because she knows that she is in the wrong. I think you need an expert opinion, and perhaps a lawyer's letter.

You can put what you want in your garden. If it blocks the vent the neighbour will have to move it. It isn't a party wall as such.
However, if it comes to selling you have to be honest about disputes with the neighbours these days.
Another problem is that you should leave a gap big enough to be able to sweep behind the shed. I know of houses that are said to be detached but nobody can get in between them.

Go and speak to your local Citizen's Advice Bureau (CAB) they will be able to give you free help and advice.

Have you spoken to your local planning department?

Hi,
My neighbour has a badly built kitchen extension. one of the walls is up the the boundary she shares with me. She has actually built right up to the boundary. she drilled a large hole in this wall earlier this year & asked me if she could come into my garden to put a vent cover over it. This wall backs onto my decked area outside my kitchen. I now want to build on this area in future so have asked her to relocate it. She has said she will not & that if I build on this area I will have to take her vent into consideration. I don't want to build for another 2 years but do want to put a shed there in the meantime. Do I have to put it a certain distance from her vent? I would like it backed up to the wall as much as possible as there will only be dead space behind it. If it backed up to the wall it would only leave a very small gap for the vent & it may not be operational. Who has the right here?
Hope someone can help. this neighbour is now being very aggressive.

Hi,
My neighbour has a badly built kitchen extension. one of the walls is up the the boundary she shares with me. She has actually built right up to the boundary. she drilled a large hole in this wall earlier this year & asked me if she could come into my garden to put a vent cover over it. This wall backs onto my decked area outside my kitchen. I now want to build on this area in future so have asked her to relocate it. She has said she will not & that if I build on this area I will have to take her vent into consideration. I don't want to build for another 2 years but do want to put a shed there in the meantime. Do I have to put it a certain distance from her vent? I would like it backed up to the wall as much as possible as there will only be dead space behind it. If it backed up to the wall it would only leave a very small gap for the vent & it may not be operational. Who has the right here?
Hope someone can help. this neighbour is now being very aggressive.