Existing Foundations (Re-build)

[aalindo]

Hi all,

I am demolishing my existing house and rebuilding. The existing house had brick spreader foundations throughout, apart from an extension built in the 1980s which has 1m concrete foundations (shown in red on the image below).

//media.diynot.com/141000_140785_43295_30272929_thumb.jpg

The new house will be located as shown on the image and has been deliberately set away from (inside) the old foundations by a couple of feet. At point 1, the new foundations will run through the old. Along the two sides annotated '2' the new foundations will run almost parallel to the old.

At point 1:

Is possible to remove a section of the old foundations and run through them?
Can i 'join' the new foundations either side of the old?
Do i just need to remove the old foundations along this side altogether?

Along sides '2' as the new foundations will run almost parallel:
Is it possible to use the old foundations as 'shuttering' on one side of the new?
If so, will it matter that they are not quite parallel, other than the new foundations will be wider along this side?
Do i just need to remove the old foundations along this side altogether?

I know the BC will have an input here, but i'd like to know at this stage (budget planning!) what the acceptable options might be.

Thanks in advance.

 

[Static]

Leave as much of the old foundations buried as possible will save on costs.. its fairly simple to break out a small section to put in new footing.. and yes you can use the old as shuttering..