Trying to determine the exact centre line of a party wall

[Bert Coules]

I have to find the exact centre line of the party wall which divides two semi-detached bungalows. Unfortunately, internal and external changes over the years mean that simply measuring between the nearest windows on each property and dividing by two won't necessarily give an accurate result.

Before the two owners get involved with anything more drastic, is it reasonable to suppose that the external chimney stack sits squarely across the dividing line? If so, then the centre of the stack marks the centre of the dividing wall.

Many thanks.

[Robin]

I assume this is about your neighbour's complaint that your loft extension has trespassed on their side (your post last year).

In that context I think the answer must be "no". I say that because the centre of the party wall *at any point* is the centre of the party wall

*at that point*. I don't think you can assume that those points are on a straight line, that the chimney stack was built precisely across the property line and four square to it, or anything else of much use. Bear in mind that AIUI you cannot even take it as an irrefutable fact that a straight party wall was built 50:50 across the property line.

But a photo or 2 might help as I'm puzzled how the chimney ends up bveing the best guide to where the party wall runs.

[Bert Coules]

Robin,

Many thanks for your thoughts, and yes, this is the ongoing saga of the boundary overhang.

I entirely take your point about not being able to make assumptions about the exact position of the boundary.

I'll see what I can manage regarding some photos and some more detailed information regarding the situation.

Bert

[Chris J Dixon]

Like others, I am finding it a bit hard to get my head round the situation.

Can we assume that the party wall is in one plane?

Do you know, or can you estimate its thickness?

Can you measure to the wall internally so as to transfer its position externally?

You suggest that the windows are no longer symmetrical, but they should at least permit you to be able to chalk up externally where the internal edge of the wall lies.

If you can't do this, perhaps you need some more professional surveying equipment, and/or someone to operate it.

Chris

[Muddymike]

If you are trying to determine if your loft conversion extends beyond the party wall can you lift a floor board in the loft next to the wall and drill a small hole through the ceiling below?

That will either prove its on your side or give you a spy hole on your neighbour :-)

Mike

[Bert Coules]

Chris,

Thanks for that.

I understand that: there have been times when I've been in much the same situation.

I'll try to post a more detailed explanation a little later, with some photos if I can manage it, but the basic dispute is this:

For whatever reason, the end wall of the new rear extension and dormer was not built in exactly the position shown on the council-approved plans; the brickwork (of the extension) and the timber construction (of the dormer) are both within my side of what the drawings describe as the "alleged centre line" of the party wall, but a uPVC end fascia, some cladding and some tiling all overhang it. If the centre line is accurate then the maximum overhang is 40mm (the tiles) and the minimum is 20mm (everything else).

If the overhang exists then I am in breach of my planning permission and will have to reduce it. But whether or not it does exist, and if so by how much. depends on the *exact* location of the boundary line, so that is what has to be determined.

Bert

[Bert Coules]

Mike,

The simple, direct approach. I like it.

Bert

[Tricky Dicky]

Party walls can be a pain consider yourself lucky if yours is simply a stra ight one. Where we lived before there were some large Victorian terraces op posite, some were double fronted with the front door in the middle with roo ms either side. The next house was single fronted, one window and an offset door. When you went round the back it was vice versa the party walls dog l egged between the houses.

Richard

[Jimbo ...]

get Holmes in .......

[Bert Coules]

Oh, if only I could.

[Brian Gaff]

Besides if it ever goes to law, it may well be determined that with the variables involved you did the best you could under the circumstances, which would I'm sure piss off the neighbour.

its one of those how long is a piece of string issues. Without significantly demolishing the wall, how can you do anything other than you did? Brian

[newshound]

Are *the planners* saying it has to be reduced? Seems slightly crazy to be in a dispute over 20 mm encroachment of facia/cladding. (Accepting that neighbours are almost by definition irrational).

There was a case near where I lived in Bristol many years ago where someone had PP to rebuild a workshop adjacent to a back garden, one of the conditions being that the roof height would not change. They went and actually constructed the new roof over the top of the old one before removing the latter, with something like an extra foot of height which, for a garden only 12 feet deep made quite a difference to the light. Local council called for enforcement and the builder appealed to Secretary of State. On appeal the inspector who came down from London (retired Squadron Leader) ruled for the builder.

[Bert Coules]

Brian Gaff asked:

I spoke to the builders this morning. They say that they can significantly reduce the amount by which the fascia, cladding and tiles protrude from the basic wall. They also accept that the initial mistake was their fault and will do the job at their own expense. This will be in accordance with the planning department's running: "trimming back" was specifically mentioned.

The exact position of the party wall centre line might not now be a vital issue: the builders are happy to accept the "assumed boundary line" as shown on the drawings.

Bert

[Bert Coules]

They are. "Trimming back" was specifically mentioned.

Your extra-height roof story is encouraging.

Bert

[Bert Coules]

"...the planning department's ruling..." I meant, of course. Apologies.

[Robin]

As I think I said last year, one way of approaching the issue is to ask "could the neighbour do a mirror image loft conversion with *precisely* the same dimensions?"

If the answer is no then ISTM the value of the neighbour's property has been reduced; and someone has dropped a stitch. Luckily it seems from the OP's further posts it was the builder who - mirabile dictu - has accepted liability and undertaken to fix it. If that is delivered then I'd say the builder is, despite the error, one of the good guys.

[Bert Coules]

That is exactly the case.

Bert

[tabbypurr]

So it's open to question and trivial. Odds are they won't take it to court.

NT

[Robin]

Depends who you mean by "they". If the planning department then they don't have to as a first step. They can issue an enforcement notice. That puts the monkey on the OP's back either to comply, appeal or ignore it. If he ignores it then it is indeed the council the council's decision whether or not to prosecute. I've no idea if the OP's council has a track record of doing so; or how the OP feels about a criminal conviction and fine. (There's no jail time!) And then of course they can still require rectification.

If by "they" you mean the neighbour, then I would not be so confident if

- as seems now - it'd be a pretty straightforward case, and not one that requires a vast investment. They pay a party wall surveyor to report on the extension; the report shows the extension trespasses on their property and is not to the plans submitted; they take that to a solicitor and sue the OP. ISTM they are very likely to win - and hence get their costs as well as an order to rectify. (I'm sorry to say I'm unimpressed by the precedent of the "too high roof" as that involved no trespass on a neighbour's property, nor any obvious detriment to them.)

[Bert Coules]

I was about to make that very point. I accept that I'm in breach of the planning permission and am taking steps to rectify it in exactly the manner requested by the planners. Assuming that I can successfully do that, there will be no reason for the council to take any action against me.

They would be in their rights to do so of course if I didn't carry out the remedial work, but unless there's a problem with the neighbours over getting it done I don't anticipate that happening.

I can't immediately think of any reason strong enough for the neighbours to want to take the matter to court. But anything's possible I suppose.

Bert