On the 1st of May 2019 the long awaited 2019 version of the BCA will come into effect.
Already we are seeing clients take the forward thinking step of designing according to the draft provisions. The logic applied is twofold:
(1) avoid costly and unfactored compliance requirements, and
(2) the risk of delivering a building which is already “behind the times” and which performs below market expectations.
Here is an outline of some of the energy efficiency code requirements designers should be aware of today:
RESIDENTIAL
6 star Benchmark Maintained
NatHERS energy rating requirements remain
at 6 stars, with no unit below 5 stars for Class 2 only.
Prescriptive Heating & Cooling Loads
Separate heating and cooling load limits will ensure residential buildings perform well year-round. Larger focus on shading and fenestration strategy is required.
COMMERCIAL DTS PATHWAY
Building Energy Consumption
Achieving an energy consumption of 30 kJ/m2/hr.
Façade Performance Assessment
The thermal performance of the wall-glazing construction is to achieve a ≤ 2.0 U-Value.
Roof Colour
Solar absorptance of new roofs is to be <0.4.
Building Sealing
Pressure testing to verify achievement of <10m3/hr/m2.
R-Value Metal Clad Walls / Roofs and Spandrel
R-Values adjusted down for heat conduction due to accounting of thermal breaks.
Slab on Ground Insulation
R1.0 under slab insulation required.
Lighting Stringencies
Max. illumination power density has decreased for all building classes.
COMMERCIAL MODELLING PATHWAY
Thermal Comfort Modelling
A thermal comfort level of between a PMV of -1 to +1 is achieved across not less than 95% of the foor area of all occupied zones not less than 98% of the hours of operation of the building.
Green Star / NABERS Modelling
5.5 Star NABERS Energy Commitment Agreements and Formal Green Star Modelling are now added as compliant modelling pathways.