Removing existing foundations - necessary?

[Tufters]

I'm about to start work on a single storey extension and my drawings have a note to remove existing foundations, which are all within the new boundary and are covered by existing kitchen flooring.

My builder is quoting 2.2k to dig up the foundations as he needs a heavy digger but I can't see why they need removing. Anyone know if this is a building reg or can I get away without digging up the foundations and save myself some costs!

 

[noseall]

You would only normally remove existing found's if they interfered with the proposed found's or underground drainage.

Generally speaking it is less effort to hoof out big chunks of conc than is to try and nibble a channel through them with a breaker etc. A 3 tonne digger will deal with most domestic strip foundations and don't cost a massive amount to hire.

 

[tony1851]

There's no specific regulation, but your local BCO is the one to ask.