How close can I build to the boundary?

[zippyswife]

I’m considering a side extension. My neighbour appears to have built a side extension right up/onto the boundary. Given that they have built up to the boundary line how close am I permitted to build?
I've had 3 builders round all have given me differing opinions. From 50mm from their wall to 500 mm from their wall. I would like a definitive before I start paying for an architect (as if I can’t build very close it’s not worth my while as I only have 2metres to the side).
Anyone experienced similar?

We had exactly this and we had no gap at all. My understanding is that is the neighbour has built on the boundary then that wall becomes the new party wall and you 'own' your side of it.

You can't use it for any load bareing so would need to sort on your side to be safe. Our builder put up a stud wall against their wall and insulated it and thats it.

We didn't want a gap that would only go mouldy and damp.

Can you discuss with the neighbour? The gap is just to avoid conflict but I don't think there is a legal reason for it and no legal minimum.

I don't know what expert person you need, but I would pay for an expert, rather than listen to mn which will be no more reliable than your builders.

Thanks @Luckydog7

thanks @MaggieFS I will be getting an architect but before I pay our (2.5k) I was looking for some anecdotal real life scenarios. If I can’t go near the boundary it would be a waste to pay the architect fee!

I think Luckydog7 has hit the nail on the head.

If your extension will be the same size as theirs do what we did and agree with the neighbours to have the wall where it meets properly joined.

Thanks for the advice. I donf really know my neighbours but maybe this is the way forward 🤞🏼

You need a party wall agreement and a specialist surveyor before you do anything else. Your neighbours should have gone through this process before building their extension and a party wall agreement should have been signed. You can look it up via google. Don't spend any money on architects or builders until you have looked at the legal requirements.

Thanks @Whatelsecangowrongnow where would the record of the agreement be kept? There was no mention of it in my survey when I bought the house.

Have you looked on the planning portal on your local council website?

You need to have a chat with planning at your local council.
My neighbour wasn't allowed to build to her boundary, we are a street of semi detached houses and they said that it would give the appearance of terracing the houses if all the neighbours did the same.
When we did ours we built 250mm from the boundary and the council were happy with that.

@Whatelsecangowrongnow it isn’t on the planning portal- it only goes back to 2003 so I assume was before that?

I am by no means an expert, just someone who was in the exact same situation a few years ago.
I suggest you post your question on the Legal board as you might get some answers there.