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Increased insulation requirements for warmer, drier and healthier buildings.

H1 Energy Efficiency requirements

The Ministry of Business, Innovation and Employment (MBIE) has updated the Energy Efficiency (H1) requirements for insulating new homes and commercial buildings in the New Zealand Building code. These changes came into effect on the 1st of May 2023. Now all new building projects must adhere to the updated performance criteria for wall, floor, and roof insulation.

The purpose of the new H1 requirements is to reduce the amount of energy needed to heat new buildings and help make them warmer, drier & healthier, with less impact on the environment. The targeted reduction of energy for residential buildings is approximately 40% and for non-residential buildings the targeted reduction of the energy use is 23%.  

New R-values of building elements

Thermal resistance is rated by R-value. The higher the R-Value the better thermal resistance the product will provide, which means greater household energy savings and cost savings.

There are two types of R-Value:

Construction R-Value (Total R-Value)  - apply to a complete building element, such as a roof or wall. The new standards apply to Construction R-Values

Material R-Value - measure the heat flow resistance of a specific material, such as insulation. The Material R-Value is expressed as the thickness of the material divided by the material’s thermal conductivity.

Energy Efficiency (H1) - Compliance Methods

The Building Code provides 3 primary methods for compliance:


H1 Schedule Method

Meet or exceed the minimum R-values for building envelope components: roof, windows, external walls and floor.


H1 Calculation Method

Design a building which has an equivalent or lower total heat loss parameter than that of a reference building where the heat loss for the reference building is calculated using the elemental R-values.


H1 Modelling/Verification Method

A calculation of the energy demand for the whole building using whole building calculation software.

Energy Efficiency for all housing and small buildings (under 300m2) 

There are changes to roof, window, wall and underfloor insulation requirements within the new edition of H1/AS1 and H1/VM1 for housing and small buildings. The new R-values aim to reduce the energy needed for heating residential homes by approximately 40% over previous requirements.

The new minimum thermal resistance values as noted in the schedule method, is summarised in the table.

Energy Efficiency for Large buildings (over 300m2) excluding industrial

There are changes to roof, window, wall and underfloor insulation requirements and also the creation of new documents for large buildings - H1/AS2 and H1/VM2.The changes will reduce the energy needed for heating and cooling of large buildings by 23% on average compared to previous requirements.

The new minimum thermal resistance values as noted in  H1/AS2 and H1/VM2 are summarised in the table.


Significant improvements for large non-residential buildings

The changes will result in a significant improvement on the energy efficiency of large buildings. Dependent on climate zone, the changes will improve the energy efficiency of various types of buildings as shown in table.

At a high level the changes will result in an average 23% reduction in energy use by large buildings.

climate zones for energy efficiency

With a focus on energy efficiency, H1 changes are explained first by introducing New Climate Zones. This will allow the insulation requirements to better reflect the different temperatures experienced in each zone. MBIE has divided New Zealand into six climate zones, taking into account of climate data and territorial authority boundaries.


Districts: Far North, Whangārei, Kaipara, Auckland, Thames-Coromandel, Western Bay of Plenty, Tauranga, Whakatāne, Kawerau, Ōpotiki

Cities: Kaitāia, Kerikeri, Paihia, Whangārei, Auckland, Thames, Whakatāne



Districts: Hauraki, Waikato, Matamata-Piako, Hamilton, Waipa, Otorohanga, South Waikato, Waitomo, Gisborne, Wairoa, Hastings, Napier, Central Hawke’s Bay, New Plymouth, Stratford, South Taranaki, Whanganui

Cities: Hamilton, New Plymouth, Wanganui, Gisborne, Napier



Districts: Manuwatū, Palmerston North, Horowhenua, Rangitīkei South, Kāpiti Coast, Porirua, Lower Hutt, Wellington, Tasman, Nelson, Marlborough, Kaikōura, Chatham Islands 

Cities: Palmerston North, Wellington, Blenheim, Nelson, Kaikōura



Districts: Taupō, Rotorua, Ruapehu, Rangitīkei North, Tararua, Upper Hutt, Masterton, Carterton, South Wairarapa, Buller, Grey, Westland

Cities: Taupō, Rotorua, Upper Hutt, Masterton, Westport, Hokitika



Districts: Hurunui, Waimakariri, Christchurch, Selwyn, Ashburton, Timarau, Waitaki East, Waimate, Dunedin, Clutha

Cities: Christchurch, Timaru, Dunedin



Districts: Mackenzie, Waitaki West, Central Otago, Queenstown Lakes, Southland, Gore, Invercargill

Cities: Twizel, Alexandra, Queenstown, Gore, Oamaru, Invercargill



Our state-of the art manufacturing facility for Asia Pacific has the capacity to confidently supply the New Zealand market through our key distributors and partners following the new requirements. We have a wide range of high performing non-combustible glasswool insulation solutions for roof, wall and floor applications to help achieve compliance with the new requirements. All of our products sold in New Zealand are manufactured using DriTherm® Technology which provides moisture resistance for up to 50 years making them suitable for use in applications for commercial buildings.

Residential solutions for H1 Compliance


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