Party wall agreement

[trevorbayliss]

Thanks for the info guys.

So my trench is going to be close to my neighbours boundary wall and conservatory. I enclose a pic to help visualise.

You can see we have a tiled lean to at the back of the houses. Plus conservatories have been added. Where my neighbours boiler pipe is i am going to be removing all my side of the connected lean to (plus conservatory) and build a new flat roof extension. It is going to be positioned about 200mm to the right of my neighbours wall.

So it will be very close. Do you think my footing will have to be deeper than the walls ? That is the question i suppose. My wall will be brick and block insulated.

 

[^woody^]

If you don't want to use the Party Wall Act, then you should think that the footings won't be lower than the neighbours.

You will be looking at about one meter down though in reality.

Be prepared for shoring with some ply and timber though.

 

[trevorbayliss]

Will that garden wall have footings 1m deep then ?

Who do i ask about how i do all this work as i am planning on doing extension myself. My mate will be digging out the area for new foundations etc + concrete floor and garage. He is a builder so knows what to do, but I would like to get a bit more guidance. Do i speak to BC about this?

My architect knows very little about this area it seems as he hasn't mentioned anything about this issue.

 

[^woody^]

If you dig lower than the neighbour's house footings, then the PW Act should apply. This will involve notices, and potentially surveyors and associated costs.

If you think, or your plan drawer thinks, and specifies a foundation lower than the neighbour's, then you should serve a PW notice and go through the rigmarole.

If you don't think, or your plan drawer does not think, and does not specify a foundation lower than the neighbour's, then you would not need toserve a PW notice or go through the rigmarole.

Take your pick.

 

[trevorbayliss]

Well i need to dig next to my neighbours wall to see what is there. That way i can understand what depth i am looking at.

My architect has not specified any depth on the foundations.

I have spoken to him tonight and he mentioned a raft system. Reading about this it may be a more cost effective solution, but i am still not sure at this stage.

My total strip foundations will be 37 linear m's . So if these are 1m deep and 600mm wide then the tonnage from the foundations only will be 45. I will also need to dig down for the concrete floor in the garage, garden room and utility. So a fair bit of gigging is needed.

Do you think a raft foundation may be a better option in this case ? Our soil is pretty standard stuff. No issues with piling or unmade ground etc.

 

[^woody^]

Why would he specify a raft? Does he know what he is doing?

As for the PW Act, was my subtle hint too subtle?

 

[trevorbayliss]

So basically the plan drawer specifies the depth and you go from there, but when BC come and look and say you need to go deeper, what happens then ? Don't you go deeper, but enter into a PWA. My neighbour is well clued up on all the building issues, so cant mislead him.

The architect is not that good. He is a plan drawer and can't advise on any building issue it seems. I know a fair bit about building, so am working it all out for myself.

As to the raft system. If i need to dig out 45 T of earth for the foundation alone then lower the rest of the site for a concrete base, wouldn't a raft system be easier and cheaper overall ?

I was reading about it tonight and it seems they can be cheaper than trench foundations when you consider the amount of earth which needs removing. So if i am doing all the area in a concrete base anyway, wouldn't a raft design be a bit easier ?

 

[garyo]

Has your neighbour mentioned the pw act yet?

The thing is, your plans can specify 1.2m deep foundations and then the depth of your neighbours foundations can only be speculated until you get on and dig, so why not assume they're 1.2 too until you find out otherwise. Then, on the day, if you find out otherwise the most expedient thing to do can be to just get the concrete in and the pw act is irrelevant.

If you feel confident.

 

[trevorbayliss]

He has mentioned it. I think my next step is to dig a trial pit. I have time to kill as waiting on planning consult process. So got 5 weeks to wait. Lots to think about though.

 

[Doggit]

As to the raft system. If i need to dig out 45 T of earth for the foundation alone then lower the rest of the site for a concrete base, wouldn't a raft system be easier and cheaper overall

Now I'm a novice compared to Woody, but even I know the difference between using a raft, and general foundations. You'd use a raft for the initial build, so that the house moves as one, so it effectively floats on the raft; but if you use a raft for the extension, then it could move independently to the rest of the house. You wouldn't dig out 45T of earth for the foundations, and then lower the rest of the site for the concrete base - you'd just dig the foundation to the required depth as checked by the BCO, or you'd do it on a raft system. How are you infilling the floor between the foundations.

My first experience of this was my father building the conservatory at the rear of our house on clay, and after they'd gone down a metre, the BCO checked it, and said he wanted another metre dug, and he ended up asking for a 3rd metre before he would let them pour the concrete.

 

[trevorbayliss]

My extension floor inc garage will be concrete. So i need to dig down for sand / insulation / concrete floor. Because of this, maybe a raft system will be better for my extension considering i also have to dig out 1m for the 37m of raft foundation. Just reading about rafts last night, it seemed to be a cheaper option.

Not sure whether the raft will move separately from the house though. House is 100 yrs old, prob on a rubble spread base.