Emissions reduction

Overview

The Building for Climate Change programme is leading the building and construction sector's approach to emissions reduction and will be introducing measures to limit emissions due to the construction and operation of buildings.

To achieve our goals for near-zero building emissions by 2050, we need to reduce both the whole of life embodied carbon of buildings and transform their operational efficiency.

We have consulted on, completed technical reviews with experts and now published two technical methodologies to support consistent embodied carbon and operational efficiency assessments of buildings in Aotearoa New Zealand.

Currently, these methodologies are not regulatory documents, however they are intended to be a high-level technical basis of the proposed future regulation for embodied carbon and the operational efficiency of new buildings.

The next step is to develop more detailed regulatory proposals to bring whole-of-life embodied carbon and operational efficiency requirements into the Building Code. We will consult publicly on these requirements in 2024 and work with technical experts and the sector to ensure that tools are available to support the regulatory requirements.

In addition to what is mentioned on this page, the emissions reductions work also includes legislative changes for Waste Minimisation Plans and Energy Performance Ratings. More information on these changes will be published soon.

Whole-of-life embodied carbon

Whole-of-life embodied carbon refers to emissions associated with the use of materials in a building and the construction processes throughout the whole lifecycle of the building including initial construction, maintenance, renovation and demolition.

It includes the embodied carbon of construction materials, for example timber, concrete and steel, (including their production) and emissions from activities such as transportation, construction and waste disposal.

The Building for Climate Change programme is considering measures to support three main ways of reducing the embodied carbon of buildings:

• improving new building efficiency, for example ensuring new buildings are resilient, built-to-last, and as big as they need to be and that we are making the best use of existing buildings,
• improving material efficiency, for example designing smarter buildings that use less material for the same functionality and performance, reducing waste at both construction and demolition stages through greater reuse and recycling of materials,
• reducing the carbon intensity of construction materials and products, for example through using lower carbon materials such as timber or reducing the emissions from the manufacture of materials such as concrete and steel.

The proposed measures have been outlined, and consulted on, in the Whole-of-life Embodied Carbon Framework.

In response to the feedback received on this Framework, we consulted with technical experts from New Zealand and around the world to develop and publish a technical methodology for assessing the whole-of-life embodied carbon of buildings in Aotearoa New Zealand. 

The whole of life embodied carbon methodology support the consistency of embodied carbon assessments of buildings in Aotearoa New Zealand, enabling early adopters to incorporate the methodology in their own processes. It is also intended to introduce embodied carbon assessments to those parts of the sector that may be less familiar with the concepts.

While embodied carbon assessments are currently voluntary, this methodology is intended for use by anyone involved in the design, construction, operation and management of buildings in Aotearoa New Zealand.

Embodied carbon assessment examples

View examples of embodied carbon assessments produced by members of the building and construction sector that use MBIE's technical methodology as a guide.

Operational efficiency

Operational emissions are generated with energy and water use when running a building, that is the emissions from heating and cooling, ventilation, lighting, cooking, hot and cold water, and running appliances. They can be direct, for example from the use of fossil gas or coal in heating and cooking, or indirect, for example from electricity generation and the wider network.

Operational efficiency refers to how much energy and water you use to keep your home or building comfortable and healthy to be in. There is a focus on efficiency to ensure homes and buildings are healthy and comfortable to be in, while also reducing energy and associated emissions.

A building with good operational efficiency is cheaper and easier to keep healthy and comfortable. Through smart building design, we can be healthier, reduce emissions, reduce peak energy demand, and save on power bills for homes and businesses.

To reduce the operational emissions from the use of buildings we can:

• improve the thermal performance of buildings and indoor environment qualities, for example through the way the building is oriented and designed, and through good insulation and ventilation
• improve energy efficiency within buildings, for example through more energy efficient heating and cooling systems and lighting
• reduce fossil fuel use, for example by moving away from fossil gas or coal to renewable energy sources.

These measures have been outlined, and consulted on, in the Transforming Operational Efficiency Framework.

These measures will support a shift away from fossil fuels. About 4% of New Zealand's domestic emissions in 2018 were from fossil fuels used in buildings for space and water heating, cooling and cooking.

The Building for Climate Change Programme will also work to improve the operational efficiency of existing buildings through:

• actions currently in place such as the Energy Efficiency & Conservation Authority's Warmer Kiwi Homes Programme
• the continued rollout of the Healthy Home Standards, and Kāinga Ora's work to improve the operational efficiency of its building stock.

 The operational efficiency methodology provides a method of calculating the operational efficiency and emissions of a new building. The intention is to improve the consistency of the assessments and reporting of operational efficiency and emissions across the sector.

The main intended audience for the methodology is people carrying out operational efficiency assessments and those who may wish to carry out these assessments in the future. We expect that most building sector participants, including homeowners, would typically interact with user-friendly tools based on this technical methodology rather than using the methodology itself.

Operational efficiency assessments have the biggest impact on operational emissions and indoor environmental quality outcomes when undertaken in the early design and concept stages. Research shows that smart design can deliver lower carbon buildings at no additional cost. Design choices made at this stage can lock-in many aspects of building performance for the lifetime of the building, unless substantial upgrades are undertaken later - which are likely to be more costly and may be more carbon intensive.

The next step is to work with technical experts in the sector to develop an Energy Modelling Protocol to go with the Operational Efficiency Technical Methodology and support consistent outcomes-based energy modelling.

2020 frameworks consultation

In 2020, the Building for Climate Change programme asked the public for their views on our proposals to increase the operational efficiency and reduce the whole of life embodied carbon of buildings in Aotearoa New Zealand.

Read more about the consultation - mbie.govt.nz