About the project
Timeframe: 4 years
Total levy funding: $2.308m
Too many New Zealand homes are cold and damp in winter, overheated in summer, and expensive to run. Damp and mould alone cost the country about $8.7 billion each year in health and productivity losses. Overheating and interstitial moisture (hidden moisture between building layers) are also growing concerns.
Why? Because current compliance pathways and wider industry design practice don’t dive into the detail of how people actually live in their homes. Both design and daily use matter – and they need to work together for a comfortable, dry home. We need a better, integrated methodology to help deliver this in practice for all New Zealanders.
Led by BRANZ, this four-year project will deliver next-generation modelling techniques and practical compliance pathways to keep homes comfortable, dry, healthy, and affordable. It’s backed by $2.34 million in Building Research Levy funding and support from MBIE, industry groups, and global experts from the Fraunhofer Institute for Building Physics.
Key project outcomes
- Real-world modelling: Creating new indoor climate models and occupancy profiles (patterns of how people use their homes) based on BRANZ’s long-term monitoring, so housing designs reflect the real, different ways people live to deliver drier, healthier homes.
- Better compliance pathways for internal moisture: practical, easy-to-apply risk matrix for Clause E3/AS1 to guide design decisions on heating, ventilation and thermal performance, including thermal bridging.
- A Verification Method for E3/VM1, co-designed with MBIE, to help designers chose advanced moisture-control strategies tailored to real conditions.
- Future impacts for energy and ventilation: Insights and data to inform updates to energy efficiency (H1) and ventilation (G4) clauses, supporting improved tools for cost effective, people-focused design choices.
- Best-practice guidance: Tools and training to make modelling workflows easier to use — supporting design, assessment, and retrofits that deliver genuine comfort, health and cost benefits.
- A focus on retrofitting: Durable, innovative approaches so that home upgrades improve living conditions, reduce liability risks, and lower long-term costs.
By building on BRANZ’s 60 years of expertise in building quality, this project will help designers create homes that truly work for Kiwi families - healthy, resilient, and affordable for future generations.