Tell how efficient UPVC double glazing is

[stevepbuk]

Hi, I got my house fitted with UPVC double glazing in 2009. Is there any way of telling how efficient they are. I cannot remember getting anything to tell me at the time. I know more recently all windows have had to be C or above but I am not sure when that took affect.

Thanks

Steve

 

[Notch7]

They prob had to comply with Part L which would've been centre pane value only.

I expect the glass is pilkington K with 16mm or 20mm cavity. Aluminium spacer. No argon gas fill.

u value of 2.0

 

[crank39]

Wasn't it April 2002 all that C rated 24mm minimum thickness low e business came out, think the u value thing was more recent still