Replace previous conservatory with extension up to the boundary line?

23 Jun 2014
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United Kingdom
Hi all,
got a question for people familiar with boundary line/PWA scenarios.
FYI: the boundary line in question is marked as "ours" on the property deeds.

We have started work on our rear extension, which includes tearing down our existing conservatory, and building a rear extension.
When the plans were drawn up, it was assumed that the current conservatory, and a short brick wall protruding out from it were on the boundary.

We have an LDC for the proposed work and plans were approved by building control.
We had served a PWA notice to our neighbours for building up to the boundary, and while we have received verbal approval we hadn't received anything back in writing yet. This is what was specifically written in the notice:

The proposed works are: new rear extension for property. The existing conservatory which borders the party wall will be demolished, with additional foundations and drainage work completed before the erection of the new rear extension. The wall of the side extension will sit adjacent to the boundary between the properties, in the same position as the existing conservatory.

However, we've since realised that the original conservatory was NOT build up to the boundary line. The picture attached shows lines for where the current conservatory was built, the "internal" boundaries within each property (neighbours let me measure up to confirm this) and where the boundary line would exist as the middle marker.
The wall that protruded out was in line with the conservatory for about 5 feet, and then has a fence that runs all the way back.
The fence is the original chicken wire fence, but our neighbours and the previous owners of our property have grown a lot of shrubs/vines right up to the fence on either side, so cannot easily see where it runs.
One thing that we can see, is that on the wall the original brackets for the fence is still there, and seems to be between the conservatory wall and the boundary lines.

Can anyone confirm if it will be possible for us to build past the current conservatory boundary so that our external wall of the extension matches up with the "internal" boundary line?
The nieghbours husband is away for work until wednesday night, and they dont want to give any comment on this yet.
We can amend our plans for building control etc.

The neighbours perceive that us building over could affect them selling their property in future, however I can't see how that can affect it as we are still building within the boundary lines.

In fact, the way I see it is that they have had access to our land as the boundary was moved inwards by the previous owners. Is there any precedence that states that land could have been "ceded" over to them by the previous owners not building to the boundary properly?

Picture showing all of the lines

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Surely you agree between you where the boundary line is and nothing (including any roof fascia’s etc) can overhang the boundary. Simples.
So.. can I take that to mean it would be ok to go as far as our internal boundary, as it still wouldn't overhang over the actual boundary line?
There is only one boundary line. That is the boundary line between the two properties that you both agree on, assuming it can be agreed upon.
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Have you assigned a PWA surveyor? What do they say on the matter?
Have you assigned a PWA surveyor? What do they say on the matter?
Find the centre of your party wall, and that is the position of the boundary on the external face of the wall.

Then, no part of the extension wall, or roof can cross that line. Nor foundations unless the PW award says it can.

You have not ceded any land to the neighbour just because the previous conservatory was set back from the boundary line. The boundary is still the boundary and does not change

Your PW surveyor can't comment untill he has been formally instructed - ie your neighbour dissents by not returing the agreement in writing.

Your LDC is based on everything being built on your side of the boundary, otherwise you are in breach of planning permission and the LDC is invalid.

You don't need to change your building control plans when walls are moved slightly.
Thanks all for the comments.
The centre of the party wall is definitely the white line in the middle of the downpipe, as i measured from both sides both internally and externally.
The downpipe is the original one from when the house was built (metal one), and no one has done any work to repair/replace it. it's actually still in fairly good condition.

I think part of the issue I had created for myself here was that I had written the notice to my neighbours myself, and apparently sent the wrong one (Section 2 instead of Section 1 and 6).

I don't have a PWA surveyor in place yet, but may need to get one as they are dissenting.
They are claiming that the wall of the old conservatory is the legal boundary, and not the centre of the party wall.
They say they have backed this up with a "surveyor friend", though from what I can tell this is based on speaking to them on the phone, and no one else coming out to take measurements.

The husband has been away on business and only got back late last night, so I haven't been able to speak to him directly on this matter.

I will try and speak to him, but my view is that I will have to now do the following:
  • Get a PWA surveyor in place. If they want their own one they can.
  • Get the correct notices sent out.
  • Get the boundary line established, so that their is no confusion on either side.
  • Anything that is built will be up to, but not across the boundary line (i.e. so no part of the roof will overhang).
Will the PWA surveyor be able to determine the boundary line?

Regardless of where I build the extension up to, I will be making sure from now forwards the boundary line is known and as the maintainer of the boundary (i.e. fence) I will be making sure the physical boundary is also up to the boundary line.

A party wall surveyor will not determine the exact position of the boundary but will run up extortionate fees in the process.

Boundary disputes are a minefield, I went to a boundary dispute seminar recently and the expert said the one piece of advice he gives all clients when they first approach him is "don't do it." But he still makes a good living with clients spending tens of thousands of pounds arguing over a few inches.

The best option is to reach an amicable agreement with the neighbour. I can see their point of view, due to previous mistakes with the position of the boundary fence it looks like you are trying to steal 300mm of their garden. Hopefully sanity will prevail and you can convince them that the center of the party wall is the correct boundary. Assuming it is shown that way on the deeds and it isn't some strange staggered boundary.

In the meantime withdraw the party wall notice before you find yourself in a costly party wall dispute.

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