"John" wrote in message
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"Alexander Galkin" wrote in message
...
snip

The cost of excavation has to include digging next to an existing
unreinforced wall without colapsing it; excavating one large enough to
accomodate working room and the angle of repose of the earch;
disposing of the extra earth.

I understand that. Excavating will be done by a pro.

I could be wrong, but you shouldn't have any problems with collapsing the
existing foundation. Once the subfloor is in, which yours has been for ~50
years, an effective box is created. That's why it's normally advised to
not
backfill until the subfloor is installed. Just don't hit the wall with the
hoe.


In large commercial buildings, excavation next to an existing foundation is
a very touchy (and expensive) endeavor, and involves some serious inspection
(before and after) and monitoring of the existing structure. I can't imagine
it being such a casual job on a residence but I could be wrong.

JTMcC.