Summary of confirmed changes with NCC 2022 impacting Metal Roofing and Roof Ventilation

In August 2021, sweeping changes to the National Construction Code were advised with a large focus on energy efficiency and condensation management. Whilst most industry experts agreed that change was inevitable and for the good of Australian consumers, it was met largely with disdain from existing builders and stakeholders as just yet another hurdle to overcome in an increasingly difficult industry to navigate. 

Added to the pressures of a lack of trade due to COVID-19, supply chain issues have persisted along with an increase in supply costs. These compounding events have forced a considerable amount of builders into liquidation, and subsequently, surviving builders have faced even more pressure to ensure they deliver a quality product at a cost that doesn’t blow the pre-existing budget.

Announcing new changes to the code that will likely add further cost to an existing build is not the news that builders want to hear, but unfortunately, the reality is that the National Construction Code has delayed the changes as long as feasibly possible to allow the construction industry to catch up. They have also announced an extended grace period specifically for the energy efficiency and condensation management sections of the code, meaning that the changes will not come into effect till October 1st, 2023. 

Whilst energy efficiency has been at the forefront of consumer minds for a while, for far too long homes have been built without a glancing look towards managing condensation. This is likely the biggest change in building practice moving forward as it has been revealed that ‘risks associated with water vapour and condensation must be managed to minimise their impact on the health of occupants.’ This is backed by a performance requirement and is the most critical aspect of the industry moving forward.

The energy efficiency of course is just as critically important and the Australian Building Codes Board has not been shy in determining some critical factors of energy efficiency in the most drastic of changes across the roofing and cladding industry. Climate zones 1-5 (NT/QLD and most of WA/SA and NSW) now have a roofing restriction to colours with a solar absorbance of over 0.64. Wall cladding is also restricted to 0.70. This applies to both tile and metal roofs in what is a huge change to colour schemes nationwide. This means popular roofing colours such as Monument will no longer be available to install from Oct 1, 2023. It is estimated that over 70% of the colour ranges for tile roofs and up to 35% of metal roofs are impacted. Fortunately, Colorbond had the foresight to update their colour range and include 3 new colours as recently as last week, all under the threshold.

The colder states however were not forgotten about with mandatory ventilation standards applied to all homes in climate zones 6-8. A combination of eave and ventilation at the ridge is applicable to all homes with exceptions given to unsarked tile roofs, insulated panel roofs and concrete roofs.

A bugbear to builders in the last NCC was an exception to ventilating sanitary areas and kitchen exhausts into a ventilated roof space. This clause was often confusing and difficult to apply and has since been removed, stipulating now that all exhausts are to be exhausted either to a shaft or outside air.

Finally, the last change revolves around taking a whole roof approach to ceiling insulation requirements. The minimum R-Value of ceiling insulation is now determined by multiple factors including the climate zone of the area, pitch and design of the roof, the solar absorbance of the roof, whether under-roof insulation has been installed and of course whether or not the roof is ventilated. How the roof is ventilated is also taken into consideration, with the requirements increased from a simple application of 2 whirlybirds to 1 whirlybird per 50m2 of ceiling area or equivalent, or alternatively 1 solar-powered whirlybird per 200m2 of ceiling area.

Ultimately what does this all mean? Australia is moving into better minimum building practices and with a priority placed on building more sustainable, energy-efficient homes, the future is bright for the next generation of homeowners.

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