You may recall GIW’s article last year on the Fifth Estate website titled, “Decoding BCA Section J: The new greener Building Code of Australia”
This article gave a detailed account of the raft of stringent measures introduced into the BCA 2010 Section J Energy Efficiency provisions.
To assist our clients, GIW has undertaken a review of BCA Section J 2011, and report that by and large , the 2010 measures have remained relatively unchanged for for Class 3-9 buildings.
Critically, one distinction between BCA 2010 and BCA 2011 is the mandating of 6 Star Energy Ratings for Class 1, 2, and 4 buildings.
BCA 2011 Section J – Volume 1 – Part J0.2 states,
“The sole-occupancy units of a Class 2 building or a Class 4 part must –
(a) For reducing the heating or cooling loads –
(i) Collectively achieve an average energy rating of not less than 6 stars; and
(ii) Individually achieve an energy rating of not less than 5 stars”.
This BCA Provision has been adopted by Victoria, Western Australia and South Australia. New South Wales defers to BASIX; Northern Territory and Tasmania defer to BCA 2009 Section J.
The introduction of higher energy rating requirements aims to improve the liveability of our built stock, thermal performance and subsequently lower operating costs. This provides selling agents with a platform from which to differentiate the new 6 Star apartments from that of pre-existing 5 Star standard assets.
The relative increase in construction cost will be dependent on a number of key factors. Critically, modest changes to the building at the concept design stage will incur less additional cost , if at all, than trying to “fix” a poorly considered design. Industry professionals should have a sense of the likely implications of the 6 Star provisions; and have the insight to identify opportunities and respond with innovation.
Examples of architectural design elements for consideration:
- Responding to heat transfer between car park level and apartment floors
- Ceiling cavity depth requirements and insulation nominations to penthouse level apartments
- Wall cavity insulation nominations for optimised floor areas (NSA)
- Strategic fenestration strategies – avoid excessive windows to floor area
- Thermal performance glazing solutions
- Emphasis on passive design strategies as a key function of the building façade treatment.
- Cross flow ventilation strategies
- Locating non-habitable rooms to the West and living rooms to the North