Townhouses/rowhouses in this area (Northern Virginia) have not been built with block "party" or "common" walls since at least before 1983.
The standard now is two 1" thick sheets of drywall. And nothing is supposed to penetrate that wall--not pipes, not cables, not the neighbor's electrical service...
Point is, there does not necessarily need to be a block wall for them to be considered two buildings (or 10 buildings, in the case of a typical row of townhouses).
[This message has been edited by brianl703 (edited 12-18-2006).]
