Grunff wrote:
Hi all,

Anyone know where I can get k values for different types of windows?
Specifically, I'd like to compa

- single pane leaded windows (real leaded, with the lead all the way
through, not stuck on) in a steel frame

and

- 18mm double glased sealed units in an oak frame


On a sort-of-related topic, I'm insulating my house at the moment.
As part of this, while I've got the plasterboard off, it's fairly easy
to add a sheet of kingspan inside the wall, that slides out on concealed
runners over the windowsill, forming a tightly fitting shutter.

In use, it looks like a 3cm or so deep alcove, with trim round it.