Increasing the flexibility of H1 energy efficiency
Posted: 27 November 2025
MBIE has made targeted changes to the acceptable solutions and verification methods for H1 Energy Efficiency to improve clarity, flexibility and affordability for designers, builders and homeowners.
These changes follow a public consultation from December 2024 to February 2025 and build on the already announced decision to remove the Schedule Method as a ‘deemed to comply’ pathway, announced in July 2025. A review of the H1 settings in 2024 had identified opportunities to better balance upfront building costs and longer-term benefits.
The overall level of energy efficiency and insulation required remains unchanged and will continue to help created warm, dry and energy efficient buildings across Aotearoa New Zealand.
The changes to H1 energy efficiency include:
- more flexibility in insulation requirements with the Schedule Method being removed as a compliance pathway for insulation
- clearer measurement rules, with the roof, wall and floor areas being measured using overall internal dimensions to ensure more consistency
- improved modelling methods in H1/VM1 and H1/VM2 to better align with modern building practices
- new requirements to ensure thermal bridging from wall framing is more accurately accounted for
- enhanced tools and tables for windows and slab-on-ground floors to cover more common building scenarios.
The updated AS/VMs take effect immediately, and a 12-month transition period will run until 26 November 2026. Designers have a 12-month transition period to fully adopt the changes by that date.
MBIE will work closely alongside the sector to ensure there is widespread understanding of the changes and how they should be implemented during the transition period.
Read the updated H1 energy efficiency documents.
Other updates
In July 2025, MBIE published the first version of the Building Product Specifications, effective 28 July 2025. As a consequence of publishing the Building Product Specifications, many acceptable solutions and verification methods were revised to cite the Building Product Specifications. Many of these documents were published as new editions with a modern look.
Some minor typographical corrections have been made to some of these documents:
- Building Product Specifications
- B2/AS1
- C/AS1
- C/AS2
- C/VM2
- E2/AS1.