The Window Energy Rating Scheme (WERS) is accredited by the AFRC - which means that WERS ratings are compliant with the NCC. Reports are prescribed both the window performance for total window U Value (Uw) and total window Solar Heat Gain Coefficient (SHGCw).
U-value measures how well a product prevents heat from escaping. It is a measure of the rate of non-solar heat loss or gain through a material or assembly. U-value ratings generally fall between 2.0-10.0 W/m2.K for Australian products.
The lower the U-value, the greater a window's resistance to heat and cold flow and the better its insulating value.
Solar Heat Gain Co-efficient (SHGC)
SHGC measures how well a product blocks heat caused by sunlight. SHGC is expressed as a number between 0 and 1. The lower a window's SHGC, the less solar heat it transmits.