Extra Deep Foundations for Small Rear Extension Drainage pipes, concrete, footings and foundations. Post your questions and find answers here

[Sandy737]

Hi all.

Planning a small rear extension. Our post code is RH12 5XQ.
Building Control have told me due to the proximity of a neighbours mature oak I will need more than the standard foundations (i.e. option B below)
I need a ball park as to how much this is likely to cost, if it's as bad I think it will kill the budget and we won't be able to afford any of it and I won't bother getting the drawings done.
Tried a few local builders with this question but they didn't even bother to reply.

A) Standard 10 meters of trench 1m deep + 13m2 of concrete floor.
B) Standard 10 meters of trench 2m deep + compressible material + 13m2 suspended concrete floor.

What would be most helpful to us is, if someone could say something like;

for just the foundations and assuming there are no snags, then for each you're looking at around
A) ? thousand
B) ? thousand

I know there are a ton of things that will affect the cost of any job. I just need some helpful person to take a stab at it.
Any ideas on this will be so helpful, thanks.

[welsh brickie]

You wont be able to get a costing because its down to the building inspectors recommendation, As soon as you dig down to the area you think is ok, he can come round and make you dig further, increasing labour costs, waste removal, concrete etc.
Have a word with him, voice your concerns, he is quite approachable in my opinion, you could try deep pile foundation costs they are more accurate.