Fair Party Wall Cost Split

[pete1980]

Hi, my adjoining neighbour is building a ground floor extension to his kitchen and dining room. We plan to do the same ourselves later in the year so have agreed to build the wall down the boundary as a shared party wall and split the cost.

Our own architect has recommended we agree the cost split upfront before they start to avoid any debate later and I'm looking for some ball park indications to understand what is fair?

Details are as follows:
- Wall extends 4m out from the property
- Mono pitch roof, eaves height 2.3m at the outside and 3.8m max height
- Standard dual skin construction, blocks on their side (internal) and pointed brickwork on the outside facing our patio. The wall will be raised slightly above the height of the roof by a brick or two with a coping stone on top, and the flashing in to the brickwork.
- Concrete foundations proposed as 1m deep and 60cm wide
- Location is Warwickshire

Any thoughts on what a typical build cost would be for the wall, and hence what a fair proportion to contribute would be please?

Thanks
Pete

 

[^woody^]

Their builder needs to itemise the work if after all, he is building it.

 

[pete1980]

Hi Woody,

Yes we have asked them to do this too, just that they've chosen their builder already and I think there is a family connection, wanted a second opinion to make sure it is reasonable as I have no idea what the right ball park costs should be

Thanks

 

[jeds]

Why not let them build their side of the cavity wall with wall ties positioned and you build yours when the time comes. The only thing you need to split then is insulation. And possibly a bit of temporary protection - i.e. some poly sheet and a few battens.

 

[pete1980]

Hi John,

We did consider and discuss that too but ruled it out for a few reasons...

I won't bore you with them all but one of the key ones is there is likely to be at least a few months gap between the projects and they want to get theirs completed, plus it avoids any headaches if ours didn't progress for any reason (e.g. we don't yet have planning in place)

Really I'm just after a rough order of magnitude cost to know if we are in the right ballpark, e.g. are we talking £100s (presumably not), £1000s, more...

Cheers
Pete

 

[^woody^]

I'd say hundreds, not thousands.

Let them build it at their expense. They could use blocks externally not bricks, if you are going to use it as your internal wall. That will keep the costs down.

They could give you an estimate of the cost, and your proportion of it. Bear in mind that your proportion is not half, and should be less than half. But don't pay it yet, or just give them a token few hundred.

Then when you come to build, you get an estimate from your builder. Then compare, and negotiate your bit.

If the wall is being built astride the boundary, then you will acquire rights to use it regardless.

But it comes down to whether they really want to come to an agreement, it they just want "something" out of you, or if they want to get as much as they can out of you.

 

[mfarrow]

Agree with woody. £500 tops.

 

[wessex101]

I'd go a bit higher say £1000 each party for the cavity wall and foundation.

Also as Woody said why are they facing the flank wall with brickwork? Make sure it is built as a "separating" wall and not just a bog standard external wall to make sure you get the required sound insulation.

 

[mfarrow]

You can probably count a few more hours at the digger and a day or so building the skins. That's it really apart from the cost of blocks.

The cost of extra concrete pour would be easily absorbed by the delivery, pump etc. which both parties need at some point anyway.

I make that £500 each being generous.