Regularisation query

[stinkyspanner]

We have got ourselves into a bit of a situation with an extension we had built under permitted development. To cut a very long and depressing story short the work was done without informing building control, and by the time we found out that we or the builder should have informed them of what was being done it was already finished or near enough.
Anyway we applied for a regularisation certificate and this is where things began to unravel badly, it turns out that the foundations are not deep enough and so it requires underpinning before they will sign it off which is fair enough.
The builder reckons he can get resin injections done and have it signed off by an approved inspector, I'm not keen on that it just sounds like another bodge. Regardless of that am I right in thinking that regularisation can only be signed off by building control, and not an approved inspector?
I know someone will suggest asking building control but they don't take phone calls and take weeks to respond. I'm hoping that there may be someone on here who knows how the system works. It's High Wycombe council if that makes a difference
Many thanks

[stinkyspanner]

Thank you Equus, I've actually done the regularisation application already- that was when BC asked for proof that the foundations were deep enough and a trial hoke was dug revealing that they are of inadequate depth. The builder then get a structural engineers report which said that the foundations need to be 1.8m (due to the proximity of a tree and soil type) when in fact they are 1.2 at best and at some points less.
This was when the builder, having accepted responsibility really began to squirm and is trying to find another way out.

[stinkyspanner]

Ok, thank you that's all helpful and pretty much confirms what I suspected. I just wanted some confirmation really so that Im less likely to be fobbed off by the builder.

I will update as things develop

[stinkyspanner]

Slight update, I had a 'proper' builder come and have a look and he gave me a fairly eye watering (but not surprising) quote to sort it out and get building control sign off. I came to an arrangement with the original builder who has paid £10k towards the cost of the remedial work. It's not really enough, but I suspect he would have folded the company had it gone to court so it's about the best outcome, plus I can get the idiot out of my life..