In May 2019 signification changes were made to Section J in an effort to combat rising greenhouse gas emissions and increase the efficiency of buildings in Australia. JP1 requires buildings to have features that facilitate the efficient use of energy for sealing the building envelope against air leakage and, conversely, for utilising air movement to assist heating and cooling whenever appropriate.
The wide span sort by the architects, combined with the new stringent energy efficiency requirements within the NCC posed serious limitations on what products could be used; so EBSA, in partnership with Schneider Louvres (Germany), developed a special solution for the SHORE school which has resulted in one of the best commercial louvre systems available in Australia, the BT90; delivering the best of both worlds - Natural Ventilation and Energy Efficiency without design compromise.
Use of aluminium to secure louvre blades creates an immediate issue in terms of thermal performance, each aluminium cross member essentially acts as a thermal bridge resulting in typical WERS ratings >5.
Domestic louvre systems using 6mm glass in an aluminium blade holder have a limited ability to overcome these thermal issues but the problem was resolved in the SLS BT90 system as the depth of frame needed to accommodate IGU's allowed thermal breaks to be integrated into both the perimeter frame and the blade holders. The result is a system which on WERS delivers a U value of 2.4, is certified to AS2047 at spans of 1740mm wide and can achieve acoustics ratings of Rw 42.