On November 27th, 2025 MBIE updated the settings for compliance with the energy-efficiency requirements of clause H1 of the Building Code.
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 previously 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 identified opportunities to better balance upfront building costs with longer-term performance benefits.
What Clause B1 Requires
Clause B1 (Structure) requires that buildings, building elements, and sitework must withstand likely loads including wind, earthquake, live and dead loads, and other environmental actions. These requirements apply during construction, alteration, and throughout the building’s life.
The clause includes mandatory objectives, functional requirements, and performance criteria. It takes into account the intended use of the building and the consequences of failure. Compliance can be demonstrated through Acceptable Solutions (such as B1/AS1) and Verification Methods (such as B1/VM1 and B1/VM2), which are published by the Ministry of Business, Innovation & Employment (MBIE) and provide recognised pathways to meet the Building Code.
The overall level of energy efficiency and insulation required remains unchanged and will continue to support the construction of 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 roof, wall, and floor areas now measured using overall internal dimensions for greater 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, with a 12-month transition period running until 26 November 2026. Designers must fully adopt the changes by this date. MBIE will work closely with the sector to support understanding and correct implementation throughout the transition period.
What Does This Mean for Builders and Designers?
From 27 November 2026, all building consent applications must demonstrate compliance with the H1 Energy Efficiency requirements using the Calculation Method.
The Calculation Method is based on the Schedule Method but introduces flexibility by allowing thermal performance trade-offs between building elements. This means walls, windows, floors, and the roof can vary in performance—as long as the total building performance still meets H1.
This method offers opportunities to reduce overall build costs by using lower-cost, high-performance products such as insulation, instead of relying on more expensive high-performance slabs or glazing.
For builders and designers aiming to optimise costs—especially for specific build typologies—there can be significant advantages to using the new rules immediately. To do this:
- The framing fraction must be known before applying for consent.
- A thermal designer will be required to complete and verify the calculations.
For more information and to read the updated H1 Energy Efficiency documents, visit www.building.govt.nz or click the button below if you’re on the ITM website.