On Tuesday, September 11, 2012 8:36:21 PM UTC+1, 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

I added an new internal skin to form a cavity wall as part of an extension. However, the new foundation was deeper the the one running alongside, and the BCO wanted me to "overpour" the old foundation, so I guess the two were effectively locked together. Only a few inches overpour was required. However my new foundation was a couple of feet lower !

So it might be a good idea to do something that locks the two together.

Simon.