"Lyle B. Harwood" wrote in message
nc.com...
In article , JTMcC
wrote:

? n 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.

In my experience, all here in Seattle, with commercial the issue is the
duty to maintain horizontal support to an adjacent property- the
doctrine called "late support".

In my experience with residential, the units are usually free standing,
far enough apart and shallow enough that there isn't significant danger
of removing horizontal support.

Obviously, exceptions occur on hills and in medium density multi
family, and in those cases your statements are absolutely correct, but
for the most part, in many Seattle neighborhoods, you aren't going to
disturb your neighbor's land by removing your foundation.

The process is, therefore, quite a bit more casual after an initial
inspection.

--
Lyle B. Harwood, President
Phoenix Homes, Inc.
(206) 523-9500 www.phoenixhomesinc.com

I'm not talking about "far apart", I'm talking about excavating directly
next to an existing foundation. In commercial construction it is done
rarely, and at great expense and effort under strict scrutiny. Existing
cracks are meticulously mapped, strain gages are installed, cubic dollars
are spent. And damage is guaranteed, the goal becomes to minimize it. It is
never treated casually, especially by the engineers and insurance companies
involved.
Maybe the poster is looking to excavate a distance from his existing
foundation, but I got the impression his addition basement was to be
directly adjacent to it.

JTMcC.