Building above 1st floor extension

[laurencellewelynbellend]

We are currently considering putting on offer in on a house with a ground floor rear extension, which was added around 2001 (according to the date of the planning permission).
We would want to add a storey above this to create an extra bedroom but am concerned whether the depth of the footings would be deep enough to support an extra storey.
Does anyone know if building regs in 2001 would have required the footings of any extension to be deep enough to support a second storey? Obviously I can't dig a pilot hole to check as its not our house! (If not then we won't buy the house.)
I am going to ring building control tomorrow - is this the sort of thing they can tell me over the phone? I can see the application made for building regs and planning on the online portal but can't view any details of the application. (In derby)
Thanks all

They would only have put in foundations deep enough to support a second storey if they thought, at some point, they would extend upwards. When we built our garage on the side, we chose to put in deeper foundations as we knew, at that point, that we would want to go higher in the future. If they had no plans to extend then why would the spend the extra money on putting in deeper foundations?

You can go into the council and request a copy of the BR application which should have the details of the foundations used. This might cost a small fee. Not all councils have everything online but they usually have the records stored somewhere. Or you could ask the owner for the original paperwork, it's in their interest to dig it out if it means a sale.
There would be no regulation requiring them to build bigger foundations but they may have done it to preempt further work - the paperwork should tell you.

What do the current owners say? As others have already said it is unlikely to have deep enough foundations unless they planned to extend upwards at a later date. If they say it has then I am sure they will allow a test hole to be dug to confirm as part of the sale.

Agree with pp. Our attached neighbours bought their house with a large wraparound single storey extension in about 2008 (the extension was done in 2005). Last year they wanted to extend and did dig a hole to investigate - foundations were too shallow. Builder / surveyor said they'd have to knock it down and start again which was prohibitively expensive.

They converted the loft instead - is that an option?

Thanks all for your responses. I had been under the impression recent extensions were meant to be deep enough to.support a second storey but maybe not after what you have all said. I was about to ring building control when had a call to say our buyers have pulled out, which means we can't offer anyway! Grrrrr!