Andrew Gabriel wrote:


Cavity walls go back before 1900 in some windswept coastal areas,
and gradually work their way across the rest of the country over
the following 40 or 50 years.


When we talk of a cavity wall in relation to a semi, are we all talking
about the party wall, or the other three?

I would expect the external walls to be cavity, but the party wall to be
9" brickwork for 30s houses. YMMV of course, depending on location etc.

Have I forgotten/missed something?

Andrew