On Tue, 17 Nov 2009 17:34:14 -0500, mm
wrote:

Speaking of soundproofing, is there anything in the building code or
common practice that would indicate what separates my townhouse from
the next one?

My house was built in 1979, and I see one layer of cinder blocks in
the basement and the attic.

I know back in the '70s block wall cavities were filled with what I
called "perlite". Looked like the garden perlite material.

It was Florida condos and the block walls separated the living spaces.
It provided sound and insulation value.