On Sep 11, 8:36*pm, Garry wrote:
We built our current garage a while back its a single skin breaze block rendered wall. We have Building Control for this.

We are wating to convert this to a habitable room and are going to brick the outside. *Can I just lay the new foundations along side the old at the same depth

Garry

I have added an outer leaf to an existing solid wall.
I dug out to the depth of the bottom of the existing footings and
poured more concrete coming to above the existing footings, ie "L"
shaped cross section.
In some places the existing footing was quite deep so I just filled
the trench up to about 200mm below the ground level.

Don't forget the cavity wall insulation. Can be mineral wool bats or
foam.
Worth spending some time getting the insulation right.