Our buildings’ colour palette today is very different to that of 50 years ago. From traditional brick walls and dark roofs, an improved understanding of how these colours impact on building thermal performance and efficiency has resulted in an evolution in building design that takes into account climate zones and building use, and utilises colour to reflect or absorb heat while still enabling creative expression. This evolution has been supported by Bluescope with a wide range of high performance, full colour range steels and is now standardised in building practices under the NCC 2019. Dark coloured roofs will no longer be permitted under the Deemed to Satisfy (DtS) provisions. Commercial buildings will need a light-coloured roof, with all climate zones (except for Climate Zone 8) requiring a maximum solar absorptance of 0.45 to comply. This means that any commercial roof assessed under the DtS provisions will need to be Surfmist®, Classic Cream™, Paperbark®, Shale Grey™ or Evening Haze®. All medium or dark coloured roofs, including “green” roofs, dark concrete and membrane roofs require a performance-based solution using JV3 to demonstrate compliance.
|Deemed to Satisfy||Performance Solution|
|MetecnoPIR Insulated Panels: acceptable external skin colours based on BlueScope’s guidelines on max skin temperature|
|Classic Cream™||Classic Cream™||Classic Cream™||Classic Cream™|
|Shale Grey™||Shale Grey™||Shale Grey™||Shale Grey™|
|Pale Eucalypt®||Pale Eucalypt®||Pale Eucalypt®||Pale Eucalypt®|
|Manor Red®||Manor Red®||Manor Red®||Manor Red®|
|Woodland Grey®||Woodland Grey®||Woodland Grey®||Woodland Grey®|
^ Note: limited warranty – contact MetecnoPIR for further details
Solar Absorptance (SA) is the fraction of the total incident solar radiation that is absorbed by the roofing material, with the remainder being reflected. SA is expressed as a ratio between 0 and 1. A roof with a lower SA will absorb less heat, compared to a roof with a higher SA, which will help in keeping the roof space and the building cooler.
For detailed information on NCC 2019 Volumes One and Two please refer to the ABCB website. Volume One of NCC 2019 primarily regulates multi-residential, commercial, industrial and public assembly buildings and some associated structures. NCC Volume One requires the Solar Absorptance of the upper surface of the roof to be less than or equal to 0.45 for the DtS pathway. Roof surfaces with SA greater than 0.45 must use the Performance Solution pathway to compliance.
MetecnoPIR are guided by the NCC and the BlueScope’s recommendations for appropriate colours, with the addition of special requirements specific to insulated panel. MetecnoPIR roof panels acceptable external colours based on COLORBOND®’s guidelines of maximum skin temperature can be seen below
|PROPOSED Bondor/Metecno Panel’s’ acceptable external skin Solar absorptance values based on BlueScope’s guidelines on max skin temperatures|
|Application||Roof – max solar absorptance value|
|Panel Type||Exposure Category|
|Exposure category 1 – Extreme inland||Exposure category 3 – Cooler regions of mainland Australia|
|Wilcannia, Oodnadatta, Swan Hill, Mardie||Toowoomba, Mackay, Cooma, Port Stephens, Omeo, Gladstone, Bowral, Lithgow, Bright|
|Exposure category 2 – Majority of seaboard Australia||Exposure category 4 – Tasmania|
|Melbourne, Sydney, Brisbane, Townsville, Adelaide, Perth, Cairns||Hobart, Launceston, Devonport|