New homes and buildings will be more energy efficient and better for the environment

Posted: 29 November 2021

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Through the Building Code update programme, MBIE have published the biggest updates to the energy efficiency acceptable solutions and verification methods in more than a decade.

On the 29 November 2021, The Ministry of Business, Innovation and Employment (MBIE) released the biggest energy efficiency updates to the acceptable solutions and verification methods in more than a decade.

This update is being made following a consultation that received more submissions than the last five years of updates combined, reflecting the high level of public interest in improving energy efficiency.

In the consultation, we received overwhelming support for the changes from all parts of the sector including residential home owners and tenants. Over 98% of responses supported increases over the status quo in the shortest time possible. The submissions also highlighted a number of challenges to implement these changes. The feedback can be summarised to "go as far and fast as possible – without breaking anything in the system".

More information on the 2021 Building Code update.

Climate Zones

We're introducing six new climate zones to better reflect the specific weather experienced in different parts of New Zealand. This will allow new homes and buildings to be designed and built based on the climate they're built in.

Residential and small buildings

MBIE is proceeding with changes to roof, window, wall and underfloor insulation requirements. The level of increase across the different building elements varies but is still achievable for current insulation products and construction methods in New Zealand.

MBIE will be further exploring options for higher performing insulation in walls as part of the revision to the standard for timber framed buildings (NZS 3604 Timber-framed buildings) which is currently underway.

Large buildings

Compared to residential buildings, we received stronger support in the submissions for higher levels of change to the insulation requirements for large buildings. The changes in insulation requirements for large buildings are the greatest achievable while still using current design and construction practices in New Zealand.


We are introducing a verification method for the energy efficiency of HVAC systems, making it easier to show compliance with the Building Code and allowing building owners to better monitor the performance of their HVAC system and know that the system is using energy optimally.

Natural Light

We have created new acceptable solutions and verification methods for clause G7, due to the increase in the number of multi-unit dwellings built in recent years.

These will ensure home and buildings have sufficient amounts of daylight for the people who occupy them.

The existing out-dated Verification Method G7/VM1 will be replaced by a new verification method that allows professional designers to use computer modelling software to design buildings to ensure sufficient natural light is provided in complex buildings.

Other changes

We've also revised a test method cited in Verification Method 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.

We're also updating the acceptable solutions and verification methods for B1 Structure to cite four new standards and make editorial corrections to the geotechnical requirements.

Operating protocols on standards

As part of this year's update, we are also are publishing two new operating protocols to provide increased transparency and certainty about the activities MBIE undertakes as stewards of the Building Code. The protocols outline how MBIE references standards in the Building Code system and supports the development of standards.

Transition Period

There will be a one-year transition period for the sector to understand and prepare for the changes before they become mandatory in 2022. However, the new window insulation requirements in the warmest climate zones will see a two-step approach with an interim increase in the next year and an additional increase in the following year. By the end of 2023, all parts of the country will have a similar minimum level of window insulation requirements.

The transition period for the 2019 update for building on liquefaction-prone ground and the entire 2020 update have now ended and these changes are now in effect.

Earthquake geotechnical engineering practice series

As part of this year's update, MBIE are re-issuing the guidance documents "Earthquake geotechnical practice series (Modules 1 - 6)" under section 175 of the Building Act.

These modules were developed alongside the New Zealand Geotechnical Society and Engineering New Zealand and were first published in 2016 and 2017.

The updated guidance documents address feedback received from the geotechnical sector and ensure that they continue to be regarded as the current, credible references for geotechnical design of buildings

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This information is published by the Ministry of Business, Innovation and Employment’s Chief Executive. It is a general guide only and, if used, does not relieve any person of the obligation to consider any matter to which the information relates according to the circumstances of the particular case. Expert advice may be required in specific circumstances. Where this information relates to assisting people: