As the ACT moves toward NCC 2025, some familiar wall and roof details will need to change for homes in Climate Zone 7.
One of the most notable changes is external wall construction. Direct-fixed cladding will generally no longer meet the Deemed-to-Satisfy pathway, meaning many rendered foam, fibre cement, weatherboard and similar systems will need to move onto a drained and ventilated cavity.
That means more than simply adding a batten. The cavity generally needs to be at least 12 mm deep, remain clear for drainage, and provide ventilation at both the top and bottom.
This can flow through to window flashings and reveals, slab edges, eaves, parapets and other penetrations, so these details need to be considered early rather than worked out on site.
Roofing is also changing, particularly for raked and skillion roofs. Where insulation follows the roof line, builders will need to make sure a continuous ventilation path is maintained above the insulation and is not blocked during installation.
Before starting an NCC 2025 project, check that the cladding, roofing and membrane details you are using have been updated for the new requirements.
If you’d like support reviewing your processes, please reach out to the MBA ACT team.
📞 (02) 6175 5900
📧 workplace@mba.org.au
