finding out foundation depth

elaneh

hi all
can anyone help, I am being asked by a potential buyer how deep the foundations are of the extension of my Victorian house (kitchen and bathroom added at the back in a single story in the 1970s I think) they want to have an upstairs bathroom and say they can't afford to buy if they have to start from scratch. I cant see anything in my papers from when I bought

do you know if local council's keep records of such things? our planning dept is open for two hours a day on the phone and I haven't got through all week
Elaneh

AdrianC

There is no way on the face of this planet that your LA will have any information on the foundations of your c.40-50 year old extension...

If it was 10yo, they would have the planning details, and maybe even still the BR sign-off paperwork, but...

The only way you can give them anything approaching a definitive answer is with judicious use of one of these...

00ec25

possibly, but rather unlikely

a) planning permission does not always require submission of "full plans" showing exactly how deep trenches would be dug. Planning permission is more concerned with appearance and impact

b) I have no idea how the world worked back in the 1970's, but building regulations plans (which would state depths) may not have been required for such a project as the certification of compliance would have been done by inspection and sign off.

c) chances of such info being readily accessible from the 1970's?

John_Smith_2019

Was the extension part of a government funded home improvements scheme?
I seem to remember something of this nature being done to many Victorian houses in the 1970s.
'Grant Improvements'?
(I think it was free work to your house, even if you owned it outright. Not just for council owned properties. Could be wrong about this?)

If so, the same extensions may have been built on all the houses in that street by the same builders at the same time.
So I would start by talking to all the neighbours.
Explain that you are willing to pay a reasonable fee for copies of any paperwork they may have...

AlexMac

As others say above, it will be technically difficult and administratively challenging, if not impossible for you to answer this question.

But it begs the question; why are they asking YOU (as opposed to a builder or surveyor)? I take it from your wording that you already have a single storey extension but no upstairs bathroom, and that they are thinking of adding a storey to the existing extension to create one?

Anything is possible. But given that when we did a simple garage conversion to our mid 1980's house a year ago, our Council building control officer demanded extra foundations across the 2.3 metre span of what used to be the up-and-over garage door...
... even though it already had a beam across the top, was remaining as a single storey with a lightweight flat roof, and we were simply replacing the heavy door with a few courses of bricks and a 1.8m timber window.

So even if your buyer engaged one of those Mickey Mouse private sector Approved Inspectors to "ensure" (ahem) compliance at the design, build and sign-off stages they'd be unwise to bet on getting away without someone inspecting (ie- digging down to expose) the footings.

But of course its not up to you to tell them that. So maybe the best you can do is to say that, to the best of your knowledge, the extension is structurally sound in that at no time during your ownership has there been any cracking or movement. And of course agree if they want to send in a surveyor to dig up your back yard (again, not something you should suggest)!

Then the ball's in their court!

G_M

Planning application certainly won't have those details.


Building Regs certification might but from the 1970s...........????

bouicca21

My dad built an extension in the late 60s or possibly early 70s and I still remember him talking about being required to have 15 foot foundations for it (the rest of the house was 1930s and he thought the foundations would only have been 3 foot).

AnotherJoe

00ec25 wrote: »

possibly, but rather unlikely

a) planning permission does not always require submission of "full plans" showing exactly how deep trenches would be dug. Planning permission is more concerned with appearance and impact

b) I have no idea how the world worked back in the 1970's, but building regulations plans (which would state depths) may not have been required for such a project as the certification of compliance would have been done by inspection and sign off.

c) chances of such info being readily accessible from the 1970's?

Back in the 1970's my father and i built a small extension at the back of the house, single story.

The rules said the foundation had to be dug to x depth. The soil was incredibly tough going, we were having a really hard time digging it out, and we got about half way down to the required depth and the inspector that came out to sign off the work so far (it was signed off at various stages through the build) said, in effect" well that looks deep enough this is like solid bedrock" and signed that stage off.
So even in the incredibly unlikely event records from back then still existed, which i very much doubt, they would say the foundations are X depth when in fact they are 0.5x depth.
If your buyers are interested then have them pay for a builder to come in and ascertain using AdrianC's high tech equipment.

Slithery

bouicca21 wrote: »

My dad built an extension in the late 60s or possibly early 70s and I still remember him talking about being required to have 15 foot foundations for it (the rest of the house was 1930s and he thought the foundations would only have been 3 foot).

I don't believe you

Either you have your numbers wrong or it was a 10 storey extension. I can imagine that in the late 60s that 15 inches would have been acceptable.

bouicca21

Slithery wrote: »

I don't believe you

Either you have your numbers wrong or it was a 10 storey extension. I can imagine that in the late 60s that 15 inches would have been acceptable.

Well I’m getting on so memory may be failing, perhaps I am fantasising about his amazement about the requirement ...

2 storey extension on London clay. It was some while after subsidence had become a big issue because of claims following an exceptionally dry summer.

I thought even Edwardian houses had 18 inch foundations

John_Smith_2019

I seem to remember that in the 1980s newbuild houses had foundations dug to a depth of about 1 metre.
But maybe it depended on the soil type and region etc?