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BRANZ reinforces support for higher energy efficiency standards

19 July 2024

BRANZ reinforces support for better Kiwi homes through higher energy efficiency standards

Last year, new energy efficiency standards under clause H1 of the New Zealand Building Code were introduced that require better thermal performance in new homes, including more insulation. The changes aimed to improve New Zealanders’ health and comfort and help to reduce the country’s carbon emissions. They were a step towards aligning with international best practice and the expectations of consumers.

Since the new standards were introduced, BRANZ has actively supported the industry through the changes via an online information hub, helpline guidance, and a national seminar series. This support has been very well received by the industry.

We understand that the government is considering reviewing the changes to H1 in response to concerns about rising material costs and housing affordability, and homes overheating due to increased insulation.

The industry is facing unprecedented challenges and pressures due to rising material costs and housing affordability issues. These are serious problems that need urgent solutions. We welcome the Government’s focus on addressing these issues.

At BRANZ, we’re contributing to this effort by targeting more research into cost-effective building materials, construction techniques, in support of regulatory frameworks that reduce overall building costs.

At the same time, we’ve been working with industry to identify cost-effective ways of delivering the H1 requirements, which can be achieved without reducing insulation standards.

Ahead of a potential review, we’d like to put forward five key reasons why we believe the standards should be maintained:

1. Standards are based on scientific evidence

The updated standards reflect the latest science and evidence on how to achieve optimal thermal performance in different climates and building types. Reversing the changes would mean that the industry would continue to rely on outdated and simplistic methods, which do not deliver the desired performance outcomes.

2. Insulation does not cause overheating

Research has dispelled the common misconception that insulation causes overheating in homes, especially in summer. Insulation reduces the transfer of heat between the inside and outside of a building, keeping the indoor temperature more stable and comfortable throughout the year. In winter, insulation prevents heat loss and keeps the home warmer. In summer, insulation prevents heat gain and keeps the home cooler.

3. Poor design is the problem

BRANZ research has also shown that, if a home is overheating, design is the problem. A house should be considered a system. Factors contributing to thermal performance include site orientation, the number and position of windows, shading, and ventilation. In combination, these elements affect how much solar radiation and natural air flow enter and exit a building, and how well they can be controlled to suit the occupants' needs. A well-designed home takes into account the local climate, the sun's path, the prevailing winds, and the thermal characteristics of the building materials, to achieve optimal thermal comfort and energy efficiency. To help inform these decisions, BRANZ has 24 exposure sites around the country to test and monitor a range of climates and exposure risks.

4. Avoiding the costs of reversing the changes

Research by BRANZ and others has shown that energy-efficient homes have lower lifetime costs, as they save on energy bills.

Furthermore, the government has spent considerable time and resources to develop and implement the updated H1 standards, in consultation with the industry and other stakeholders. BRANZ has also invested in research, guidance and education to support the industry through the changes. Undoing them would erode this investment and create unnecessary administrative and regulatory burdens for the government and the industry.

5. Aligning the building sector with national climate goals

The H1 updates are an important contribution to the country’s efforts to reduce greenhouse gas emissions. New Zealand has pledged to achieve net zero carbon emissions by 2050, and the building sector has a significant role to play in this.

We encourage the government to keep the updated H1 standards, while we continue to work with the industry and other partners to overcome affordability challenges and realise the benefits of higher-performing homes