Foundations near drop

[BB Kong]

Hi, I am hoping to build a structure in the garden that adjoins my garage. This could be the first of many questions asking for advice.

The structure will be 8m by 4m singe story. Two of the walls will replace fences at the boundary with two separate neighbours.

Where the 8m wall is to be, there is a change in levels between my garden and my neigbours garden. Ground level in my garden is about 1.5 meters higher than ground level in his garden.

I have spoken to two architects both have given my conflicting advice.

The first said that a raft foundation would be all that was needed.

The second said that this wasn't the case and I would need to dig down below the level of my neigbours garden or insert piles and a steel beam. He also said that I would need a structural engineer to look at it at £750 plus VAT.

On top of architects design fees and planning and possible fees to get building regs plans I am looking at over £2000 before I can even get this off the ground. Not to add the possibiity of party wall fees as I will be building to the boundary (the architect tells me these are 750 per neighbour). I'm on a tight budget and I thought I was just building a simple structure that would cost very little to do. Hence my first question about the foundations.

Any ideas what sort of foundations would be the norm for this project and is a structural engineer necessary?

Thanks for any advice.

 

[rssteve]

I'd guess not a raft.Imagine if the soil below gave way with the weight. Could all slide down into the neighbours garden.

 

[rssteve]

Whats the angle of the embankment and i persumed there is no retaining wall?

 

[jeds]

A raft might do the job but I can't see how you would protect the 1.5m high boundary? A raft would push the ground laterally so unless the retaining wall is designed to take that sort of load (presumably it isn't) your neighbour will come home one day and find it on his lawn. The alternative is to take your foundation below the level of the base of the retained land - plus a depth to protect from drying out and frost. That could mean a foundation up to 2.5m deep and not an easy thing to do without disturbing the retained boundary. You might be better off with piling.

 

[GeoffJ]

We might be looking at this the wrong way.
If we can have a Grade Canyon Sky walk then something a little more down to earth can be built without any foundations at the boundary.

 

[BB Kong]

Thanks all fr getting back to me. Been away for a few weeks with no internet.

Whats the angle of the embankment and i persumed there is no retaining wall?

The embankment is a vertical drop. No retaining wall, just a fence. Although I've never looked at whether the fence goes straight to the floor of neighbours garden or just to the floor of mine with a retaining wall below.

I think I will investigate the piling option. I had assumed that architects would be experts on this, but I think that was my inexperience in projexts like this. Maybe I should consult a structural engineer before an architect?

We might be looking at this the wrong way.
If we can have a Grade Canyon Sky walk then something a little more down to earth can be built without any foundations at the boundary.

Heart fluttering just watching that clip

 

[freddiemercurystwin]

I think I will investigate the piling option. I had assumed that architects would be experts on this, but I think that was my inexperience in projexts like this. Maybe I should consult a structural engineer before an architect?

No an architect is not (usually) qualified to make a decision but can surmise a solution, a structural engineer will be required, if all you need is the structural solution then consult an SE don't bother with the architect/designer. But if you want some drawings a contractor can follow if this 'garden structure' is significant then probably a good technician who can liaise with his SE is the way to go. There is no one solution fits all though with regards to the structure and little significant information to comment further. And I agree a raft sounds potty here.

 

[KenGMac]

I think I will investigate the piling option

Hi.

Suggest you have a look at "Shire piling" they have a web site and they do a version that will support a conservatory or similar.

As an aside Shire can and will undertake the Design element and if needed [at a cost] will obtain Planning and Building control approvals.

Ken.

 

[BB Kong]

Thanks all. Investigated the options and I thin my budget is too small. Going to convert the garage to a habitable space instead and put a wooden structure up instead.