Buildings primarily contribute to climate change impacts through:
- the energy they use when the building is occupied
- the greenhouse gas emissions from the extraction, processing, transport and installation of building materials and their maintenance and eventual disposal or recycling
- urban and landscape design and planning.
The New Zealand Productivity Commission report Low-emissions economy notes that, while New Zealand’s absolute contribution to global emissions is small, our per-person gross emissions are one of the highest among developed countries.
Greenhouse gas emissions from our buildings arise from the manufacture and transport of their construction materials, the use of fossil fuels and electricity (part of which is produced by fossil fuels) in their operation and the landfilling of construction and demolition waste.
A 2016 Royal Society report Transition to a low-carbon economy for New Zealand found that greenhouse gas emissions can be reduced in New Zealand residential and commercial buildings through better energy management and improved minimum performance standards for appliances.
Emissions reductions can also result from:
- improving insulation levels
- retrofitting existing building stock
- integrating renewable energy systems
- supporting innovative green building designs.
The aim and the problems
The aim is to build net-zero carbon buildings - buildings whose greenhouse gas emissions over their life cycle are within New Zealand’s commitments to a net-zero carbon economy.
There are currently few economic incentives to encourage action, and the New Zealand Building Code does not require buildings to be net-zero carbon. Even if the demand were there, the industry has significant gaps in skills and knowledge required to deliver net-zero carbon buildings.
BRANZ is producing a significant number of resources to assist, including the bulletins:
- BU655 Building blocks for new-build net-zero carbon houses
- BU669 Tools for measuring carbon in new-build houses
- BU679 Introduction to calculating whole-of-life carbon footprints of houses
- BU684 Thermal modelling tools for houses
And the study reports:
- ER86 SESOC Top Tips for Low Carbon Design
- SR488 Energy performance of innovative water heating technologies
- ER80 Reducing greenhouse gas emissions in communities – evidence and opportunities for change in Aotearoa
- ER79 Overseas programmes for improving the operational carbon emissions from existing residential buildings – lessons for Aotearoa New Zealand
- SR479 Embodied carbon of New Zealand office and residential building services
Updated: 5 September 2025