windows? whats the right way to go?

[Thurston Garden]

Stew & Zoe - sorry I did not really explain about the draughts, but the book differentiates draughts as those that are not controllable against ventilation which, of course, is.

The book even showed thermalite/concrete blocks are being permeable to air and therefore described them as draughts - i.e. cold air entering the building in an uncontrolled manner, thus reducing it's thermal properties, and increasing the requirement to heat the interior.

I have not really started reading the book, but it does look very informative, although I think it is going to be heavy going!