On Sat, 04 Dec 2004 22:39:21 GMT, a particular chimpanzee named
"Colin" randomly hit the keyboard and
produced:

As a bit of an offshoot from this topic, is there any information on the
heat retaining properties of homes with (as mine) solid concrete walls as
apposed to a 'cavitied' wall? Are concrete walls as bad as it gets? (aside
from maybe.....copper or ice?)

It's unusual for a house to be built entirely of cast in-situ
concrete, or even concrete panels. Is this what you mean, or do you
mean concrete blocks?

Reinforced structural concrete by itself is a poor insulator (having a
conductivity of 2.3W/m°C compared to 0.77W/m°C for brick), but isn't
used over a whole wall, only to form a frame. There is usually some
form of infill panels with internal or external insulation. There
were other types of system builds (such as 'no-fines' concrete) which
were used by Councils in the '60s and '70s. I would have thought most
of these have been upgraded (or demolished) by now.

Most houses in the last 20 years have been built with concrete blocks
of varying density to the inner leaf. The conductivity can vary from
1.13W/m°C (worse than brick) to 0.11W/m°C (better).
--
Hugo Nebula
'What you have to ask yourself is, "if no-one on the internet wants
a piece of this, just how far from the pack have you strayed?"'