2025 :
27th Nov 2025:
Today, the Ministry of Business, Innovation and Employment (MBIE) has 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 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.
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. A wall framing fraction of no less than 38% shall be assumed unless it can be demonstrated that a lower wall framing fraction is appropriate for the building.
· 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.
IAONZ will be working through these changes and providing more updates for members shortly.
Read the updated H1 energy efficiency documents.
Summarised changes below :
Changes to H1/AS1
This acceptable solution is the sixth edition of H1/AS1. The main changes from the previous fifth edition amendment 1 are:
• The schedule method has been removed from the acceptable solution.
• In the calculation method, the minimum construction R-value for slab-on-ground floors has been removed. The minimum construction R-values for roofs, walls, and floors other than slab-on-ground floors are now specified directly instead of a percentage of R-values in the reference building equation.
• For multi-unit dwellings and for mixed-use buildings, the building may now be treated as having either a single thermal envelope, or multiple thermal envelopes, when demonstrating compliance using the calculation method.
• The citation of NZS 4214 has been modified to enhance clarity of requirements for determining the thermal resistance of building elements containing thermal bridges.
• The method for determining the thermal resistance of framed walls has been revised to better address typical levels of thermal bridging caused by wall framing members. As a consequence, the wall R-value in the reference building heat loss equations has also been reduced.
• The application of minimum construction R-values of heated ceilings, heated walls and heated floors has been clarified, and these minimum construction R-values no longer apply where heated ceilings, heated walls or heated floors are installed solely in rooms that contain a shower, bath or toilet.
• The method for determining the areas of roofs, walls and floors now requires the overall internal dimensions to be used.
• References have been revised to reflect the documents cited in this acceptable solution in Appendix A.
• Definitions have been revised to reflect the terms used in this acceptable solution in Appendix B.
• The performance table for windows and doors in housing in Appendix D. has been revised to better reflect commonly used window specifications.
• Appendix E. Thermal resistance of slab-on-ground floors has been revised to address buildings that have a mix of cladding types and buildings with slab edge insulation that does not cover the entire floor perimeter. The performance tables have also been expanded to include a greater range of slab area-to-perimeter ratios.
• The acceptable solution now refers to the Building Product Specifications for determining the thermal resistance of insulation materials. As a consequence, reference to AS/NZS 4859.1 has been removed from the acceptable solution with the applicable specifications located within the Building Product Specifications.
• Portions of text have been re-written to enhance clarity in the document and provide consistent language with other acceptable solutions and verification methods.
• Minor amendments have been made to correct typos, grammar, cross-references, punctuation, wording, and formatting of the document. This includes changes to headings, paragraphs, tables and figures, table and figure notes, and definitions. These amendments do not affect the level of performance required in the document but may assist in the interpretation of the requirements.
People using this document should check for amendments on a regular basis. The Ministry of Business, Innovation and Employment may amend any part of any acceptable solution or verification method at any time. Up-to-date versions of acceptable solutions or verification methods are available from www.building.govt.nz.
Changes to H1/AS2
This acceptable solution is the second edition of H1/AS2. The main changes from the previous first edition amendment 1 are:
• The schedule method has been removed from the acceptable solution.
• The calculation method has been amended to provide flexibility for the construction R-values of all building elements of a proposed building’s thermal envelope. The minimum construction R-values for roofs and floors have been removed.
• For mixed-use buildings, the building may now be treated as having either a single thermal envelope, or multiple thermal envelopes, when demonstrating compliance using the calculation method.
• The citation of NZS 4214 has been modified to enhance clarity of requirements for determining the thermal resistance of building elements containing thermal bridges.
• The method for determining the thermal resistance of framed walls has been revised to better address typical levels of thermal bridging caused by wall framing members. As a consequence, the wall R-value in the reference building heat loss equations has also been reduced.
• The application of minimum construction R-values of heated ceilings, heated walls and heated floors has been clarified, and these minimum construction R-values no longer apply where heated ceilings, heated walls or heated floors are installed solely in rooms that contain a shower, bath or toilet.
• The method for determining the areas of roofs, walls and floors now requires the overall internal dimensions to be used.
• References have been revised to reflect the documents cited in this acceptable solution in Appendix A.
• Definitions have been revised to reflect the terms used in this acceptable solution in Appendix B.
• Appendix E. Thermal resistance of slab-on-ground floors has been revised to address buildings that have a mix of cladding types and buildings with slab edge insulation that does not cover the entire floor perimeter. The performance tables have also been expanded to include a greater range of slab area-to-perimeter ratios.
• The acceptable solution now refers to the Building Product Specifications for determining the thermal resistance of insulation materials. As a consequence, reference to AS/NZS 4859.1 has been removed from the acceptable solution with the applicable specifications located within the Building Product Specifications.
• Portions of text have been re-written to enhance clarity in the document and provide consistent language with other acceptable solutions and verification methods.
• Minor amendments have been made to correct typos, grammar, cross-references, punctuation, wording, and formatting of the document. This includes changes to headings, paragraphs, tables and figures, table and figure notes, and definitions. These amendments do not affect the level of performance required in the document but may assist in the interpretation of the requirements.
2024:
Media Release - New insulation standards cost-effective and lower the cost of living
Read our latest media release HERE
2024 :
The latest update information on Building Code H1 is available here:
https://www.building.govt.nz/building-code-compliance/h-energy-efficiency/h1-energy-efficiency/
BRANZ H1 Hub - Access this HERE: http://h1hub.branz.nz
2023 :
The Ministry of Business, Innovation and Employment (MBIE) has announced an extension period to the upgrade of insulation in houses.
Roof, wall and floor R-Values remain the same until 1 May 2023
The date for transition to the 5th edition H1/AS1 and H1/VM1 documents will remain as 3 November 2022. From this date, the previous 4th edition H1 documents can no longer be used for building consent applications.
However, where building consent applications for housing are submitted before 1 May 2023, roof, wall and floor minimum construction R-values can be equivalent to the previous (4th edition) requirements.
Read more HERE
H1 Industry Hub for insulation information
BRANZ H1 Hub - Access this HERE: http://h1hub.branz.nz
All window and door construction in new housing now has a 2-step increase. The first step is a minimum construction R-value of R0.37 for the whole country from 3 November 2022. After that, the date of the second step varies by climate zone:
From 1 May 2023, the minimum R-value in:
climate zones 3 and 4 rises to R0.46
climate zones 5 and 6 rises to R0.50
From 2 November 2023, the minimum R-value for climate zones 1 and 2 rises to R0.46
BRANZ has also released the following Bulletins relating to the new H1 requirements and higher performance buildings – available free with a login from the BRANZ website:
Bulletin 672 Specifying floors under H1
Bulletin 670 Specifying windows and doors under H1
Bulletin 668 Complying with H1 – Housing and buildings up to 300 m2
Bulletin 661 Residential roofs with high thermal performance
Bulletin 660 Residential walls with high thermal performance
Significant Building Code update released for H1 Energy Efficiency
On 29th November 2021, the Ministry of Business, Innovation and Employment (MBIE) released the biggest energy efficiency changes to the acceptable solutions and verification methods in more than a decade. IAONZ will use this page to update and provide information and progress regards these changes.
Overview:
This year’s Building Code update means significant changes for all parts of the sector – manufacturers, suppliers, builders and homeowners. The changes go as far and as fast as is achievable using current insulation products and construction design and practices to create better quality homes and buildings for New Zealand with less impact on the environment.
Updates to insulation requirements aim to reduce energy needed to heat and cool new buildings by 23% and to heat new homes by up to 40%. This will have positive health impacts for New Zealanders and contribute to increased energy savings allowing people to heat their homes and buildings more easily and efficiently, making them more comfortable and healthier to live and work in.
There will be a one-year transition period for the sector to understand and prepare for the changes before they become mandatory in 2022.
Find out more by visiting building.govt.nz
We will be releasing more information and simple break-downs of the new regulations shortly.
Summary of decisions
1. Energy efficiency for housing and small buildings
MBIE is proceeding with changes to roof, window, wall and underfloor insulation requirements by issuing the new edition of Acceptable Solution H1/AS1 and Verification Method H1/VM1 for housing and small buildings. The new insulation requirements aim to reduce energy needed for heating residential homes of approximately 40% over minimum previous requirements.
2. Energy efficiency for large buildings
MBIE is proceeding with changes to roof, window, wall and underfloor insulation requirements and issuing the new H1/AS2 and H1/VM2 for large buildings. This aims to reduce the energy needed for heating and cooling of 23% on average across new large buildings over previous minimum status quo requirements.
3. Energy efficiency for heating, ventilation and air conditioning (HVAC) systems in commercial buildings
MBIE is publishing the new verification method H1/VM3 with modifications to the proposed text to clarify the requirements and address items raised in the consultation. This new verification method allows building owners to better monitor the performance of their HVAC system and know that the system is using energy optimally.
View the new acceptable solutions and verification methods for H1 Energy Efficiency
4. Natural light for higher-density housing
MBIE is publishing the new acceptable solutions G7/AS1 and G7/AS2 with minor modifications to the proposal. The existing outdated G7/VM1 will be replaced with a verification method to demonstrate compliance using computer modelling. Refreshing these acceptable solutions and verification methods for clause G7 Natural Light helps ensure people have sufficient amounts of daylight in higher-density housing.
View the new acceptable solutions and verification methods for G7 Natural Light
5. Weathertightness testing for higher-density housing
MBIE is issuing the new edition of E2/VM2 without any modifications to the proposal. The revised weathertightness testing method cited in E2/VM2 that can be used to demonstrate that cladding systems are sufficiently weathertight. The new version does not significantly change the minimum performance requirements and existing tested cladding systems will not need to be retested.
View the new Verification Method E2/VM2
6. Standards referenced in B1 Structure
MBIE is referencing the new versions of four standards in the acceptable solutions and verification methods for B1 Structure.
7. Editorial changes to Acceptable Solution B1/AS1
MBIE is proceeding with the editorial corrections to Acceptable Solution B1/AS1 without any modifications to the proposal.
View the new acceptable solutions and verification methods for B1 Structure
Transition period
The effective date for the new acceptable solutions and verification methods is 29 November 2021 with a transition period of one-year ending on 3 November 2022.
Build Magazine article - February 2022:
https://www.buildmagazine.org.nz/articles/show/building-code-changes-2021