Surely uk.d-i-y could settle this argument? Medway will respect them.

http://www.wisegeek.com/what-is-a-breeze-block.htm

I think this link is wrong. I think Breeze blocks date from the 50's
(perhaps earlier?) and were made with some sort of clinker or slag.
Certainly they were much harder to drill than today's standard (not
lightweight) concrete blocks. I suspect it might have been a proprietary
name.