Thermal efficiency
Thermal insulation
- Window triple glazed Uw = 0.86 W/m2K (pine)
- Window triple glazed Uw = 0.92 W/m2K (oak)
- Door triple glazed Uw = 0.93 W/m2K (pine)
- Door triple glazed Uw = 0.97 W/m2K (oak)
- Double glazing (on request) Uw = 1.4 W/m2K
Triple glazed as standard
We believe triple glazing should become the standard choice for windows and doors in the UK to help combat climate change. Triple glazed windows are around 30% more efficient than double glazing and can significantly improve the energy efficiency of homes, saving money on energy bills and reducing CO2 emissions.As part of Green Building Store’s commitment to promoting ultra low energy building design, we switched our Ecoplus window production to focus on triple glazing and since 1st June 2009 have made argon filled triple glazing more affordable by offering it at the same price as double glazing for Ecoplus windows and doors. The new Ecoplus3 range is also available with triple glazing at the same price as double glazing.
BFRC energy rating
The British Fenestration Rating Council
(BFRC) scheme is the UK’s national system for rating the energy
efficiency of windows and is recognised within the Building Regulations
as a method to show compliance. BFRC window energy ratings use a
traffic-light style A-E ratings guide similar to that used on ‘white’
goods (such as fridges, freezers, washing machines etc). As well as
taking U values into consideration, the BFRC energy ratings also take
into account the nominal solar heat gain provided by windows.
Every window has in practice an 'energy balance' which balances the heat loss through thermal transmittance and air leakage with the heat gained from the sun. The BFRC scheme rates an 'average' window and gives a nominal energy balance, the Energy Index to this. Where this is positive, nominally the window gains more energy than it loses. Of course in practice this will depend on the aspect of the windows, balance of north facing to south facing etc. If the nominal balance is above zero (ie positive) the the window gets an A rating. Many argue that the rating is set too low and that there is no differentiation between an A rating with an Energy Ratio of 1 and an Energy Ratio of 30 (which might be achieved with a good Passivhaus standard window).
Ecoplus3 triple glazed windows achieve an A rating under the scheme.