NCC 2025 Improving Building Performance
Navigating NCC 2025: Why Builders Need to Prioritise Heat Recovery Ventilation
The National Construction Code (NCC) 2025 is set to bring further refinements to condensation management, extending requirements first introduced in NCC 2022. For builders, airtight, energy-efficient homes need active moisture management solutions. This is where Heat Recovery Ventilation becomes critical.
Understanding NCC’s Approach to Condensation Management
Condensation-related building failures have been a growing concern in Australia, particularly in climate zones 4 to 8, where temperature differences and airtight construction increase the risk of moisture buildup.
The NCC 2022 updates (enforced May 2024) introduced several key changes:
- Mandatory direct discharge for exhaust systems (no more venting into roof spaces)
- Vapour-permeable external wall requirements
- Roof space ventilation for colder climate zones
- Automatic operation for bathroom exhaust fans
NCC 2025 is proposing to extend and refine these measures:
- Drained and vented cavities for external walls in zones 6-8
- Expanded roof ventilation requirements for climate zones 4 and 5
- Clearer requirements for ceiling and roof space ventilation strategies
While these measures will help control moisture transfer and airflow, they do not actively remove indoor-generated humidity, which is where HRV systems play an important role.
Why Heat Recovery Ventilation is the Best Solution for Builders
HRV systems extract stale, humid air and bring in filtered, pre-warmed outdoor air, maintaining a balanced indoor environment. This aligns with NCC’s goal of reducing condensation risk while improving indoor air quality.
Trapped humidity leads to mould growth, timber rot, and compromised insulation performance, causing costly issues for homeowners and warranty claims for builders. Mechanical ventilation prevents excess moisture buildup before it condenses on cold surfaces.
As homes become more energy-efficient, they also become more airtight, which increases the risk of condensation-related issues. HRV ensures controlled ventilation without energy loss, making it an ideal solution for NCC-compliant builds.
NCC 2025 does not mandate HRV, but it does require that builders implement condensation management strategies. HRV complements vapour control layers, external drainage cavities, and roof ventilation by actively removing moisture before it builds up.
How Builders Can Integrate HRV into Their Projects
- Include HRV in early design stages to ensure space is allocated for ducting and ventilation planning
- Select HRV systems that meet Australian climate needs, considering performance efficiency in colder zones
- Educate homeowners on ventilation importance to prevent callbacks and ensure they understand the benefits of continuous fresh air exchange
Future-Proofing Builds with HRV
With NCC 2025 further tightening moisture management requirements, builders must adopt proactive ventilation strategies. HRV is a crucial system for ensuring homes remain dry, healthy, and energy-efficient.