1. T101 Thermal performance Window energy rating

2. T101-2006 Energy rating schemes  NFRC  National Fenestration Rating Scheme, USA  BFRC  British Fenestration Rating Scheme  EWERS  European Window Energy Rating Scheme

3. T101-2006 FENSA  FENestration Self Assessment  Approved by ODPM as complying with Part L1  Self certification by dealer/installer  Administered by the GGF

4. T101-2006 FENSA  Self certification  Frame type  Thermal break  Low e-coatings  Gas filling  Part L1 U-values

5. T101-2006 Part L2 2002

6. T101-2006 Part L2 2002

7. T101-2006 Part L2 2002

8. T101-2006 NFRC  Operating for 15 years in the USA  Rating scheme showing;  U-value  Solar Heat Gain Coefficient  Air leakage  Factors combined differently for different climates

9. T101-2006 NFRC  6 climatic regions cover USA  Heating climates  Cooling climates  Sunny climates

10. T101-2006 NFRC U-value SHGC Light transmittance Air leakage

11. T101-2006 BFRC  Independent UK body  Spun out of UK Government funded research  Partners were Trade Associations, Laboratories, Analysts and Universities  Establishing links in Europe  May feature in the next version of the Building Regulations

12. T101-2006 BFRC rating  Takes account of;  U-value Conduction, convection, radiation  SHGC Solar Heat Gain Coefficient  Air leakage Air leakage at 50Pa, L 50

13. T101-2006 Original BFRC label

14. T101-2006 BFRC rating  DWERS  Domestic Window Energy Rating Scheme  Ratings in the range G - A  A is most energy efficient, DWER > 0  Today’s good windows normally fall in band C, -20 < DWER < -10

15. T101-2006 DWER  DWER = 218.6 x Window Solar factor – - 68.5 x (Window U-value + Air infiltration factor)  Factors of 218.6 and 68.5 recognise the influence of Window Solar factor, U-value, and air leakage in the UK  Windows will perform differently in different UK climates but will always be ranked consistently

16. T101-2006 BFRC rating  Separate values given for:  Window U-value, U w  Window solar factor, g window  Window air infiltration factor, 0.0165L 50 To allow for fuller consideration

17. T101-2006 Light transmittance  A good DWER can be achieved by selecting right SHGC  This can be achieved by using a tinted glass  Heavily tinted glass will affect light levels in a building and may lead to an increased energy use for artificial lighting  The light transmittance value is given to allow specifiers to avoid this problem

18. T101-2006 EWERS  European Window Energy Rating Scheme  Adopted in Denmark  Uses scale of A,B,C,D,E  Similar to rating schemes for domestic appliances  May be taken up in UK with BFRC as the operating agent  Will use a common label but each state will set its own classification on the basis of climate and window styles!

19. T101-2006 EWERS labelling

20. T101-2006 Linking rating to regions

21. T101-2006 BFRC rating label