In general most Glaziers in WA are well versed in Australian Regulations, however in the past 6 months we have noticed more builders questioning if their glazing is compliant. This can be a testing time for builders as glazing is a key element for many clients.
So let’s recap on glazing requirements. As per NCC 2016, Volume 2 – 188.8.131.52 external glazing:
- Total System U-values and Total System SHGC-values are required for each glazing element
- Total System U-value – W/m² .K (Uw) means the thermal transmittance of the composite element allowing for the effect of any airspace and associated surface resistance
- Total System Solar Heat Gain Coefficient (SHGCw) means the fraction of incident irradiance on glazing or a roof light that adds heat to a building’s space.
We have noticed some Glaziers recommending and even specifying glazing with Ug and SHGCg values. Unfortunately these are glass only values and must be disregarded as they are not compliant. To guarantee compliant glazing, your Glazier must specify whole window system values (Uw and SHGCw). These values encompass all components of a glazing element including the type of window, glass and frame.
To ensure a valid comparison of glazing products, NCC 2016 Volume 2 states glazing elements must be rated in accordance with the Australian Fenestration Rating Council (AFRC). The Window Energy Rating Scheme (WERS) forms part of fenestration quality assurance and certifies window performance.
The WERS Certified Products Directory is a ‘one stop shop’ that lists all tested glazing elements that are rated in accordance with AFRC. Choosing a glass maker from this website or verifying if your Glazier is a WERS member guarantees that your glazing complies with AFRC procedures and protocols and meet regulatory requirements including:
- Uw and SHGCw compliancy
- Annual AS2047 audits
- Conform to AS2047-99 or AS2047-14 for water and wind penetration