How close can you build to boundary wall?

[Devonish]

I have got planning permission for a single storey extension on the side of my house. Whilst the builder and I were setting out the site the neighbour suggested that the finished wall will be quite close the the wall. Her husband also mentioned it this evening. When no one was around I measured the distance and found it was 800mm between the corner of the extension and the boundary wall. At the front of the extension the gap is wider 1300mm. The building Inspector has visited the site to discuss foundations and he never mentioned anything.

Is this likely to be a problem? or should I just forget it and crack on with the foundations?

 

[^woody^]

You can build up to the boundary line, and on or over the boundary via the party wall act. Irrespective of the neighbours wall.

However you should build in accordance with your approved planning plans

 

[Devonish]

You can build up to the boundary line, and on or over the boundary via the party wall act. Irrespective of the neighbours wall.

However you should build in accordance with your approved planning plans

All measurements are in accordance with the approved plans. Was just wondering if I should expect a 'low ball' Thank you for your reply, I will just get on with it.

 

[lt8480]

Even if within planning - there may be party wall matters which are separate. There's quite a bit of on-line guidance on this and will depend on the proximity of their building and the depth of their foundations.

Refer to "Adjacent Excavation and 3 metre and 6 metre Notices" here for some further guidance and useful diagrams:
http://www.buildingsurveying.info/party-wall.html

As you will see excavation deeper than your neighbours within 3m of their foundations still requires notice.

 

[Devonish]

Even if within planning - there may be party wall matters which are separate. There's quite a bit of on-line guidance on this and will depend on the proximity of their building and the depth of their foundations.

Refer to "Adjacent Excavation and 3 metre and 6 metre Notices" here for some further guidance and useful diagrams:
http://www.buildingsurveying.info/party-wall.html

As you will see excavation deeper than your neighbours within 3m of their foundations still requires notice.

Thanks. That is useful, but we are building off a concrete slab. The Building Inspector suggested it as an option because the site is already concreted. It was used as a parking area and the existing concrete is 5 inches thick. Another 8 inches of concrete will be poured on top.

 

[noseall]

we are building off a concrete slab. The Building Inspector suggested it as an option because the site is already concreted. It was used as a parking area and the existing concrete is 5 inches thick. Another 8 inches of concrete will be poured on top.

Eh, WTF!

 

[lt8480]

Seems odd. I assume it has been designed though - the existing slab may well be being assumed as stable ground and just left in place, that is rather that part of the design of the structural slab in itself (as a 200mm slab might be sufficient on its own).

No doubt the existing slab doesn't perfectly align in plan layout of in height, and the quality of concrete for a drive wouldn't usually be up to the specification required for a slab design either. Also elements such as membranes etc. to consider which probably don't interface very well.

 

[Devonish]

Seems odd. I assume it has been designed though - the existing slab may well be being assumed as stable ground and just left in place, that is rather that part of the design of the structural slab in itself (as a 200mm slab might be sufficient on its own).

No doubt the existing slab doesn't perfectly align in plan layout of in height, and the quality of concrete for a drive wouldn't usually be up to the specification required for a slab design either. Also elements such as membranes etc. to consider which probably don't interface very well.

Well what can I say, the Builder and the Building Inspector thought this to be a very workable option. The original concrete was used to park various vehicles over the years. We have parked tractors (John Deere 2140) on there and the concrete has not been damaged. The parking area is larger than the slab for the extension. B835 Structural mesh will be placed in the new slab.

 

[lt8480]

Sorry Devonish, didn't mean to sound off. My comment was mainly responding to noseall. It seems slightly odd on the limited info, but as noted I suspect it is mainly to save you breaking it out and it simply being treated as "ground" rather than using it as part of the slab design. Of course it all depends on what is being proposed etc. etc.

I would just say be careful that it won't cause other problems with other parts of the design, e.g. drains are the first thing that come to mind. Sometimes these things can be great money and time savers, but other times they can just create bigger costs and or headaches down the line. Your procurement route and building contract(s) will determine whether the builders and other parties are looking ahead for these things (depending whose problems and costs they become should they occur!).

 

[Devonish]

Sorry Devonish, didn't mean to sound off. My comment was mainly responding to noseall. It seems slightly odd on the limited info, but as noted I suspect it is mainly to save you breaking it out and it simply being treated as "ground" rather than using it as part of the slab design. Of course it all depends on what is being proposed etc. etc.

I would just say be careful that it won't cause other problems with other parts of the design, e.g. drains are the first thing that come to mind. Sometimes these things can be great money and time savers, but other times they can just create bigger costs and or headaches down the line. Your procurement route and building contract(s) will determine whether the builders and other parties are looking ahead for these things (depending whose problems and costs they become should they occur!).

No it's fine It8480, this is what we are doing.
Its a single storey extension providing two extra bedrooms. There is no water required in these rooms. There is a soil pipe/drain running under one corner but there are two access covers that fall outside of the slab. We are Foster Carers (hence the need for more space) and needed the disruption period to as short as possible. Social Services are not keen on construction work whilst a child is placed in the home. It will be of block rendered construction with a 'lean to' styled tile roof with a couple of velux roof lights.

 

[Devonish]

Just thought I would give an update. The slab was poured and the walls have been started. The first course was brick for the DPC and now two course of blocks have gone up. The Building Inspector has visited when he was driving through and seems very happy.