Videos: H1 changes 2026
From 27 November 2026, a number of changes to the H1 Energy Efficiency Acceptable Solutions and Verification Methods will come into effect.
To help designers, builders and industry professionals prepare, the Ministry of Business, Innovation and Employment (MBIE) has developed a series of short videos explaining the key updates, what they mean in practice and how to demonstrate compliance under the new requirements.
Explore the videos below to learn about the updated calculation and modelling methods, measurement requirements, thermal bridging and the pathways available for different building types.
Video 1: New H1 Energy Efficiency Requirements 2026
This video provides a summary of the updates taking effect from 27 November 2026, including:
- updated calculation and modelling methods
- removal of the schedule method
- key steps designers and builders can take to prepare.
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Compliance with H1 energy efficiency is changing.
Get ready for new requirements on 27 November 2026.
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Heading: H1 Energy efficiency update
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Acceptable solutions and verification methods have been updated to make insulation requirements clearer and more flexible.
The schedule method is being removed.
Designers should now transition to the H1 calculation or modelling methods.
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Animation showing New Zealand climate zones, corresponding R-values, and a building.
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Some calculation and modelling method requirements have also changed.
The new editions of H1/AS1, H1/AS2, H1/VM1 and H1/VM2 can be used now.
From 27 November 2026, previous editions can no longer be used to show compliance.
Get ready for compliance before 27 November 2026.
More information available on www.building.govt.nz
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Logos displayed for the New Zealand Government, the Ministry of Business, Innovation and Employment, and Building Performance.
Text on screen: building.govt.nz
Video 2: H1/AS1 calculation method for housing and small buildings
If you're designing a house or small building up to 300m², this video will guide you through the updated H1/AS1 calculation method. Learn about measurement requirements, insulation and glazing requirements and the free tools available to help demonstrate compliance.
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The H1/AS1 calculation method is one way to show H1 Energy Efficiency Compliance.
It applies to houses of any size and other buildings up to 300 square metres.
Buildings with curtain walling cannot use this method.
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Animation with curtain wall shown separately from the building structure
Text on screen: AS1 is crossed out.
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Free tools for the H1/AS1 calculation method are available from BRANZ and the New Zealand Green Building Council.
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Animation showing a calculator linked to BRANZ, the New Zealand Green Building Council and key building elements including roof, wall, floor, glazing and skylights.
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Areas must now be measured using overall internal dimensions.
Roof and wall areas are net areas.
Windows, doors and skylights are subtracted.
Walls, roofs and floors must meet minimum R values, except for slab on ground floors.
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Animation of a house showing different R-values for walls, roof and floors
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Heated floors, walls and ceilings must meet special minimum R values.
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Animation of a building showing R-value and emphasising heated floors
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These do not apply if only used in rooms with a shower, bath or toilet.
Glazing is limited to 40% of the gross wall area.
Buildings with multi-unit housing or multiple classified users can be treated as one thermal envelope or divided into several.
Walls and floors between conditioned spaces are not part of the thermal envelope.
The new editions of H1/AS1, H1/AS2, H1/VM1 and H1/VM2 can be used now.
From 27 November 2026, previous editions can no longer be used to show compliance.
Get ready for compliance before 27 November 2026.
More information available on www.building.govt.nz
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Logos displayed for the New Zealand Government, the Ministry of Business, Innovation and Employment, and Building Performance
Text on screen: Building.govt.nz.
Video 3: Updated H1/AS2 calculation method for large buildings
Learn more about the updated H1/AS2 calculation method for buildings over 300m². It highlights the increased flexibility available to designers and the information needed to use the method.
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The H1/AS2 calculation method is one way to show H1 energy efficiency compliance.
It applies to buildings over 300 square metres but does not apply to housing.
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Animation of commercial buildings.
Text on screen: AS2 calculation method.
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The updated H1/AS2 calculation method lets designers optimise insulation to balance up-front cost with long-term energy performance.
The new addition gives R-value flexibility across all thermal envelope elements, giving designers more ways to reduce costs while ensuring compliance.
Free tools for the H1/AS2 calculation method are available from BRANZ and the New Zealand Green Building Council.
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Animation showing a calculator linked to BRANZ, the New Zealand Green Building Council and key building elements including roof, wall, floor, glazing and skylights.
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You'll need to know the areas and R-values of your proposed thermal envelope elements.
You'll also need the solar heat gain coefficients of your glazing areas.
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Animation of a warehouse building and sun’s rays being absorbed by the window.
Text on screen: R-value.
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Areas must now be measured using overall internal dimensions.
Based on these inputs, the tools do all the calculations for you and tell you if your proposed design complies.
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Cutaway illustration of a building showing different building elements and their corresponding R-values: 1.9 (ceiling), 2.4 (wall), 2.2 (floor), 0.48 (window).
Comply button on screen goes from red to green, indicating compliance.
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New additions of H1/AS1, H1/AS2, H1/VM1 and H1/VM2 can be used now.
From 27 November 2026, previous editions can no longer be used to show compliance.
Get ready for compliance before 27 November 2026.
More information available on www.building.govt.nz
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Logos displayed for the New Zealand Government, the Ministry of Business, Innovation and Employment, and Building Performance.
Text on screen: building.govt.nz
Video 4: Wall and floor area measurements under the updated H1 requirements
Learn the new standardised measurement approach, including the use of overall internal dimensions and how the changes improve consistency across all H1 compliance pathways.
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H1 energy efficiency now includes a clear method for determining areas of roofs, walls and floors for energy efficiency compliance.
This improves clarity and consistency across all H1 compliance pathways.
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Heading: H1 Measuring Update
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Overall internal dimensions must now be used in the calculation and modelling methods.
This means measuring areas on the finished internal surfaces of roofs, walls and floors.
Overall internal dimensions include the thickness of internal partitions.
Details on the new method can be found in the updated H1/AS1, H1/AS2, H1/VM1 and H1/VM2.
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Animation of documents H1/AS1, H1/AS2, H1/VM1 and H1/VM2, and four buildings of increasing size corresponding to them.
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Get ready before 27 November 2026.
More information available on www.building.govt.nz
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Logos displayed for the New Zealand Government, the Ministry of Business, Innovation and Employment, and Building Performance.
Text on screen: building.govt.nz;
Video 5: Thermal bridging in wall framing
Learn more about the updated requirements for accounting for thermal bridging in wall framing. Including:
- how wall framing fractions are calculated
- the assumptions designers must use
- how the changes improve the accuracy of thermal performance calculations.
Watch now to learn how thermal bridging is accounted for under the updated H1 Energy Efficiency requirements and what this means for compliance assessments.
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Thermal bridging happens when heat travels more easily through framing materials than through insulation.
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A wall section is shown with insulation between framings. Arrows show heat moving more easily through the framing than through the insulated areas.
Heading: Thermal bridging
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Updated H1 acceptable solutions and verification methods now require thermal bridging from wall framing to be accounted more accurately.
When calculating R values for timber or steel framed walls, designers must assume a minimum wall framing fraction of 38%, unless they can justify a lower value for the proposed building.
To work out a custom wall framing fraction, designers must count all wall framing in the same plane as insulation within the thermal envelope walls.
This framing area is then compared to the net wall area, which excludes doors and windows.
Get ready before 27 November 2026.
More information available on www.building.govt.nz
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Logos displayed for the New Zealand Government, the Ministry of Business, Innovation and Employment, and Building Performance.
Text on screen: building.govt.nz