On 13 Feb 2006 03:25:06 -0800, a particular chimpanzee named
randomly hit the keyboard and produced:

BCO wants some magic words in the spec to justify "how the windows
acheive U-value of what-ever-it-was".
Will the phrase from screwfix description:
"28mm Sealed Units with Pilkington 'K' glass"
be sufficient, or do I need to say "filled with ..." etc ?
He mentioned something about 19mm gas-filled. Is this another way of
acheiving required
U values ?

He wants to know that your choice of windows will have a maximum
U-value of 2.0W/m²K (for uPVC or timber, 2.2W/m²K for metal). Simply
writing on the plan, "windows to 2.0W/m²K" won't cut it, as 90% of
builders wouldn't know whether what they're buying meets the
requirements (and why should they, that's the job of the Architect or
plan drawer). He needs you to state _how_ it's going to achieve a
U-value of 2.0W/m²K; ie, does it have a low-emmissivity coating and
what is the gap between the panes?

Getting a full plans approval is not an end in its own right. The
point is to make sure that the plans can be relied upon on site, and
that if followed, the completed work will comply.
--
Hugo Nebula
"If no-one on the internet wants a piece of this,
just how far from the pack have you strayed?"