In article ,
Grunff wrote:

I'm not, I'm just curious about the relative heat loss in
different rooms of our house, and the choices the architect
made. It seems to me that the leaded windows lose several
hundred Watts more than the double glased ones, and I wanted to
see if this is really the case.

Don't forget to factor-in the Hereford&Worcester
planning dept into the architect's decisions.
Are the leaded windows the ones visible from any
direction to which the public has access?

--
Tony Williams.