Neighbour say extension on their side 10-20mm

[nickname7890]

Hello
Please please help
we are doing Nc kitchen extension
Neighbour A and B signed party wall. Neighbour A a bit trickier side as said they didn't want us on the boundary wall only up to so we have a kink on that side slightly but that's fine we understand

All along done all we can to keep everyone happy and we are finally nearly there with all walls built and back doors due next week. Finally I will have a kitchen and not believing 5 of us in a bedroom! Neighbour B been super all way through
But...
Today neighbour A said they think we are 10-20mm on their side
They said they want to discuss and are threatening action
I don't know what to do
We signed party wall
Our builders said they have followed the agreement
Neighbour A has said the wall their side starts where it should but said as it goes up it veers 10-20mm towards ("over into") their side. They say we must have ordered a steel too big so the wall goes up complying with the line agreed but as it hits the steel it goes out by 10-20mm
Our builders have said the joint wall before was wavy (true). And that it looks like we are on their side because we have built a straight wall against their not straight wall

Today we have had to down tools and stop everything as our neighbors have threatened it will become a big
Problem for us

I don't know what to do I'm so incredibly anxious
Are we going to have to pull the wall down IF they are right ? Are we going to have to wait even longer with no doors on our house while we go through a disputed process with independent surveyors to work our who is right
All for 1-2 Cm?

Please please help I'm so upset I literally can't cope with this stress right now xxx

did you have surveyor/s involved previously? who prepared the PWA?

Have you spoke to your neighbour and asked them what you cane do to put it right ( if needs be). Please don't panic

How have the neighbours come to the conclusion that its 1-2cm over on their side?

Have they employed a surveyor (my guess is they haven't) because only a professional would be able to establish this.

On the surface it does sound like they are being petty especially given your opening post and them not wanting it against their wall. However, as they have raised a complaint to you it is now your job to find a fix.

Have you had historical issues with neighbour a?

Would it be worth asking them to pop their concerns in writing so you can pass to your surveyor.

You will need to know how they have come to this conclusion, so I don't think it is unreasonable to ask for them to let you know so that you can then notify your surveyor and get cracking.....

The prospect of having to write it down may actually concentrate their minds and they might back off, if not you will at least know what you're dealing with once you have it in writing.

Surely you can just cut the steel back so that it doesn't overhang the brickwork?

I so need a diagram.

Do you mean as you go down the garden the line of your extension veers onto their garden OR as your extension wall comes up from the ground, it then veers over onto their side?

Thank you everyone - it's so great to feel supported in navigating this minefield!
So they are saying that it is probably in line at the bottom where we start building the wall up. We then use bricks of exactly the same size and lay them exactly on top of one another all the way up

Our builder says it's because their wall is not straight and ours is ...
ultimately what would happen if a bricklayer had lay a brick 10mm out of place ? (They haven't but I just mean in any other scenario is there no tolerance?)

What about guttering and roof tiles at top? Do they overhang further?

No. I can see there is a "lip" ont he side of our roof which hangs over a touch
And our builder has said he already planned to
Shave it down. And we are fine with that of course
But their wall
Is "bowed" and buckles. Their wall is wonky and v old. You can see the bricks aren't even lay straight
So our builder said they couldn't build a wonky wall obviously so had to build a straight wall going up from the agreed line in the "sand"/earth

I know less than you on that matter and maybe I'm being naive, but IF the isn't straight, isn't the builder's fault and therefore their's to fix? At no extra charge?

(Obviously time will be a pain but at least not money)

Did you get this sorted out @user1494360838 🤞🏻