NZ GREEN BUILDING COUNCIL

The NZ Green Building Council (NZGBC), established in 2005, is a large membership organisation of engineers, architects, builders, developers and suppliers, professional service firms, banks, local and central government and industry associations. The NZGBC’s work includes:
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• NZGBC rating tools:
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- Homestar (for new homes or major renovations)
- Energy and Carbon Calculator for Homes (ECCHO)
- Green Star (for larger commercial buildings)
- Green Star Communities (large-scale development projects)
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• Training and certification for Homestar Assessors using these tools
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• Campaigning to government, councils and the industry for regulatory reforms and policy change – including membership of the Climate Leaders Coalition

• Events, conferences and educational resources

• Research and reports including carbon reductions, sustainable finance, lessons for NZ from overseas carbon emissions programmes, climate scenarios

• Toitu Carbon Zero certification for NZGBC as an organisation

The NZGBC Homestar rating tool and certification system records a house’s additional performance and sustainablity requirements above the NZ Building Code. Homes are assessed on a scale of 6 to 10 against NZGBC’s health, efficiency and sustainability criteria, including:
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• Double-glazed windows

• Ventilation and heating – continuous mechanical ventilation

• Continuous insulation including thermal breaks in the building envelope

• Water proofing

• Water use

• Energy use

• Carbon accounting – both embodied and operational

• Cool – design to avoid overheating

• Climate resilience and adaptation
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In December 2024 and April 2025 the NZGBC launched its Existing Homes Roadmap focusing on policies to address problems with NZ housing...
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Recommendations are:
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• A deep retrofit programme for NZ’s worst performing homes

• Expansion of the Government’s Warmer Kiwi Homes subsidies for a shallow retrofit programme for owner occupied homes

• A national housing improvement finance programme for energy efficient homes

• Trial an Energy Performance (NZ) Certificate and phase in mandatory energy and carbon emissions targets with all homes required to meet a target EPC grade when sold or rented by 2030