Roof and ceiling energy concessions from Electronic Blueprint - BCA 2008
The ABCB (Australian Building Codes Board) has posted on their website for
comment, the proposed amendments to the BCA (Building Code of Australia Volumes 1 and 2),
to be published 1 May 2008. This article draws attention to one issue - It is proposed that
the BCA extend the concessions for roof and ceiling insulation to include the following:
- The Total R-Value specified in Table J1.3 is reduced - ...
- In climate zone 1, 2 and 3, for a Class 5 to 8, 9a and 9b building with -
- a roof upper surface solar absorptance value not more that 0.55, by R0.5; or
- a roof upper surface solar absorptance value of not more than 0.35, by R1.0 and
- ...
Reference: BCA Vol 1 Clause J1.3.
This means that, for non-residential buildings, a concession on the level of insulation
in the roof/ceiling space may be made for light coloured roofs. Typical values of the
Solar Absorptance and the level of concession are given below.
The selection of zincalume roofing, light coloured tiles and the like could permit some
significant savings in the level of insulation to be selected. Whilst this concession is
important for roof, ceiling and insulation manufacturers, it also has implications for the
manufacturers of other building envelope components, such as brickwork, blockwork, cladding
and glazing. The establishment of insulation concessions based on roof solar absorptance,
and the subsequent extension of these to non-residential buildings, sets a reduced benchmark
for future deemed-to-satisfy concessions of these components.
For further information contact:
Electronic Blueprint
phone: +61 2 4360 2255
fax: +61 2 4360 2256
web: www.electronicblueprint.com.au
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