H1 refers to a clause of the New Zealand Building code that relates to energy efficiency. The H1 clause has received a big update which means big changes for the process of constructing new residential homes in New Zealand.

The intention of this overhaul is to create energy-efficient and sustainable homes as part of a global initiative against climate change. The new requirements aim to reduce the energy needed for heating residential homes by approximately 40% over the previous minimum requirements.

This change is part of New Zealand’s international commitment to the preservation of the planet by meeting climate and sustainability regulations. New Zealand, along with almost 190 other parties, committed to the 2030 Paris Agreement in 2015, which is the first-ever universal, legally binding global climate change agreement. Together with the other parties, New Zealand has pledged to carry out a global framework with the intention of avoiding dangerous climate change by pursuing efforts to limit global warming to 1.5°C. The H1 clause updates are part of New Zealand’s larger effort to be Carbon Neutral by 2050.

“The building and construction sector must play a major part in helping New Zealand achieve net Carbon Zero by 2050. The Building for Climate Change programme is MBIE’s main programme of work as the building system regulator to minimise the climate impact of the building and construction sector. The programme aims to reduce emissions from constructing and operating buildings, and to make sure our buildings are prepared for the future effects of climate change.” (MBIE, 2021)

Home Building sector changes

Image 1. Building and construction sector climate change response timeframes illustrates how this fits into the longer term and how it relates to the 2030 Paris agreement deadline and the net carbon zero by 2050 goals.

What’s Changing

Much of the changes are centred around higher requirements for ‘R-Values’ for new homes

An R-value is a measurement of the thermal resistance of a building material. I.e. how well does the material resist the movement of heat from inside the building to the outside and vice versa.

The changes for Canterbury homes include:

  • R6.6 roof insulation
  • R2.4 external wall insulation
  • Thermally broken windows
  • Low-E and Argon filled windows
  • Foundations insulated

The most substantial change is with roof construction where we can see the new requirements have doubled the previous requirements from an R-value of R3.3 (in Canterbury/climate zone 3) and the new R-value being R6.6.

Concrete foundations will now need to be insulated where typically this was not a requirement in the past.

Windows/doors will now also need to be a higher spec, including thermally broken joinery, low emissivity coatings on glass and the use of higher R-value gases between double glazed panels, like Argon gas.

The new code also revises the old climate zones to be more area-specific, the previous system utilized 3 zones where the changes increase that to 6 zones. The requirements for each zone differ to account for changes in climate around the country.

Climate zones for home building

Image 2. New Zealand according to Climate Zone.

How this will affect you

The effective date for the new acceptable solutions and verification methods on new home buildings was 29 November 2021, with a transition period of one year ending on 3 November 2022.

This means that from July, all working drawings will need to meet the new H1 criteria in order for consented plans to be issued by November.

for your new home must meet the new H1 changes by July in order for consented plans to be issued by November.

If you’re looking to build you have the opportunity to get in quick and avoid the cost implications of the changes, however this may not be an option where section titles are due later in the year.

You may also prefer to discuss this further with a member of our sales team and adopt these changes before they are mandatory as a way of future-proofing.

The H1 changes will mean we are building comfortable, healthy and environmentally friendly homes but there are cost increases to match these improvements. We expect the price of the building according to the updated H1 Clause to be approximately a 5% increase.

At a time where the industry is currently going through a range of supply issues, and we find ourselves in the middle of a building boom with dwelling consents at record highs according to the NZ Herald, Feb 2022, the H1 changes make this an interesting challenge for the industry.

As an established building company with over 40 years of experience, Orange Homes has stood strong through many industry challenges. We have spent over 4 decades building quality relationships with quality suppliers and look forward to continuing to provide you with healthy, comfortable and stylish homes. We have an extensive range of stylish and functional home plans that maximise sun position and land size.

Interested to learn more about building your dream home?

Get in touch with one of our friendly team members


H1 changes are coming into effect in 2023. Here's all you need to know about the H1 Clause, What it means for building your new home, what's changing and how these updates may impact you.