Building and construction accounts for up to 20% of New Zealand’s greenhouse gas emissions, considering all the materials used. However slowly, but surely, New Zealand is beginning to look at ways of reducing greenhouse gas emissions from all activities.

The reality is that, with emissions budgets starting this year, the building and construction industry will have to make a concerted effort to reduce their carbon footprint as well.

Emissions budgets do not come with obligations on each principal or contractor to meet a particular target. But the budgets will increasingly form the basis of Government policy for each sector of activity. These policies will have an impact on the building and construction sector as well.

Changes coming up in the short term

One important change will take place in November 2022, with an amendment to the Resource Management Act 1991. Consent authorities will have to take into account the effects on climate change of a proposed project before they can make a decision on granting or refusing consent.

The practical implications from this amendment will be felt by all applicants, whether the project they are proposing is large (like roads, renewable energy plants or mining) or small (a new house).

This change will likely mean that applicants will have to show to the consent authority what the impact of their proposal would have on climate change. It would be to their advantage if they can demonstrate, in one way or another, what steps they took to minimise, as much as possible, that impact.

Limiting the impact on climate change at every stage of a project

There are actions that can be taken at every stage of a proposed project to limit its emissions, and – with that – the impact it would have on climate change.

Design

At the design stage, applicants have choice when it comes to the materials to be used for a project. These are important because production of some materials, for example steel and cement, is more energy intensive than for others.

From the very early stages of a project, the choice of materials will contribute to the higher or lower impact the project has on climate change. While for some projects, there are no technical alternatives to the use of high-embodied emissions materials, for other projects this may be an option worth considering. For instance, the use of timber may replace steel and cement in buildings, reducing embodied emissions and locking up carbon for several decades.

Construction

When applying for a consent, the emissions from all the activities required to build a project will be considered.

One area that can be improved is minimising the amount of building and construction waste that goes to landfill. At the moment, most of the waste from construction and demolition is not recycled, but is thrown out to landfills – making up nearly 1.2 million tonnes a year, which is a third of the waste received at class 1 landfills that accept household waste (class 1). The use of recycled or alternative materials in new projects is limited.

Changing processes to avoid sending so much material to landfill and to increase the use of recycled materials would prevent the need for more construction materials to be produced, while at the same time minimising emissions from landfill.

Operation

On-going emissions once the project becomes operational are also relevant. For example, emissions from completed buildings and homes in New Zealand are significant, and have seen a 66 percent increase between 2007 and 2017.

Choices made at earlier stages, during design and construction, will determine operational and maintenance requirements for small and large projects. With the changes to the consenting process, emissions from the on-going operation and maintenance of projects will be taken into account before resource consent is granted. This provides an opportunity to design and construct projects with on-going operation and maintenance requirements in mind, so as to ensure that they do not result in high emissions. For example, designing energy efficient commercial and residential buildings that will have lower energy costs throughout the life of the building.

Some options that can be implemented in projects

A number of options have been outlined by various Government or independent bodies.

The 2021 advice to the government prepared by the Climate Change Commission outlined some of the steps that can be taken to increase the use of materials with less embodied emissions, building more energy efficient buildings and reducing waste that is disposed to landfill.

The Ministry for Business, Innovation and Employment (MBIE) prepared policy papers on the reduction of emissions in the building and construction industry. The aim was to encourage the design and construction of buildings with as little energy and water as practical, in order to reduce emissions. This would involve reusing and recycling materials as well as working with local suppliers to support product streams.

The Ministry for the Environment (MfE) developed a strategy for a circular economy. This relies on all sectors, including the building and construction sector, recovering and reusing materials so as to prolong the life of existing materials, minimise the need for more materials to be produced, and limit the amount of waste that is disposed of in landfills. MfE plans to increase investment in waste reduction initiatives and infrastructure. In order to reduce construction and demolition waste MfE plans to re-design construction and demolition materials, products, and services to facilitate reduce/reuse of resources.

These initiatives can be implemented both at the request of the principal or by contractors having them included in the way projects are delivered.

There are already examples in New Zealand of significant principals using their influence to change the way in which contractors deliver projects. Waka Kotahi is currently exemplifying this shift by providing contractual incentives to contractors to build in more environmentally friendly ways. As a part of the Waka Kotahi sustainability action plan, they have a suite of social and environmental contract specifications used in their planning and procurement. Contracts now include monitoring and management of performance to give effect to their updated Environmental and Social Responsibility Policy and Standards, which focus on resource efficiency and waste management practices.

An example of this new approach is the Penlink project, which aims to reduce carbon emissions by at least 10%, whilst also encouraging suppliers to look for ways to make even greater reductions. The tender process included a financial incentive for meeting a carbon reduction target meant to encourage design competition and challenge Waka Kotahi’s own standards to reduce construction emissions.

A further example is the aspiration by Kāinga Ora to be an industry leader in transitioning the housing sector to carbon neutral construction practices. Its Sustainability Framework focuses on climate change mitigation and adaptation aiming for net zero emissions in the operation of public housing and infrastructure through reducing embodied and operational emissions associated with its construction program.

This is a new era for New Zealand, and building and construction projects are in the early stages of transitioning to a net-zero economy.

The opportunities are here for principals and contractors to take advantage of this new direction and adopt more environmentally friendly building and construction practices, before policies are put in place that may prescribe required actions.