We are committed to delivering good environmental and sustainability outcomes as part of the design, construction and operation of our infrastructure projects.

Infrastructure sustainability rating schemes provide a consistent method of assessing, achieving, and communicating the positive environmental and sustainability outcomes associated with infrastructure projects.

The benefits of using rating schemes and tools include:

  • verification of performance (by an independent third party)
  • project teams are recognised for their achieved outcomes
  • communication of benefits (highlighting environmental and social outcomes)
  • raising the sustainability profile of projects and project partners
  • sharing of ideas at the project and industry level
  • innovation and greater environmental and social advancements
  • driving broader sustainability outcomes.

Our Sustainability Rating Scheme Policy aims to drive improved environmental and sustainable outcomes in alignment with NZTA's commitments in Toitū te Taiao – Our Sustainability Action Plan, our Resource Efficiency Policy for Infrastructure Delivery & Maintenance, Environmental and Social Responsibility Policy and Environmental plan. This helps us recognise successful sustainability performances and ensure these outcomes are incorporated early in the planning phase.

Toitū Te Taiao – Our Sustainability Action Plan
Resource Efficiency Policy for Infrastructure Delivery & Maintenance
Environmental and Social Responsibility Policy [PDF, 129 KB]
Environmental plan: improving environmental sustainability and public health in New Zealand

It also aligns with the government’s Broader Outcomes initiative and the NZTA Broader outcomes procurement strategy.

Broader outcomes

Who needs to use the ISC sustainability rating scheme?

As of September 2020 NZTA has adopted the Infrastructure Sustainability Council (ISC) as our sustainability rating scheme provider.

Infrastructure Sustainability Council website(external link)

NZTA projects

As required by our Sustainability Rating Scheme Policy, all NZTA projects with an estimated capital value of:

  • over $15 million are required to consider the merits of ISC certification
  • over $100 million are obliged to complete ISC certification, except in circumstances specified by the policy.

Projects that request an exemption to not complete ISC certification will still need to demonstrate sound sustainability practice and outcomes through adherence to relevant polices, strategies, and standards including Toitū te Taiao. Evidence of this will be demonstrated through regular reporting and other agreed measures.

The requirements to achieve ISC certification and the rating level required will be specified in our tender documents and will form part of the final contracts.

ISC certification for NZTA projects currently covers the design and as-built (construction) phases. Certification can also cover the business case phase (planning rating), operations and maintenance project phases. At this stage, NZTA does not mandate planning or operational sustainability rating schemes, but we are looking to pilot these on selected projects and these may be required in the future.

Projects part-funded by NZTA

Projects that are part-funded by NZTA and meet the threshold of $15 million are required to consider the merits of using the ISC rating scheme. At a minimum, these projects shall apply the principles outlined in Toitū Te Taiao, the specification P49 Sustainability rating scheme application during tender and delivery of capital works projects, the Resource Efficiency Policy for Infrastructure Delivery and Maintenance and other relevant government policies driving broader sustainability outcomes.

Resource Efficiency Policy for Infrastructure Delivery & Maintenance

How ISC connects with carbon emissions reduction, resource efficiency and waste minimisation

Sustainability rating encourages projects to reduce carbon emissions to mitigate climate change, and to use resources efficiently and minimise waste. Visit our sections on climate change mitigation and resource efficiency and waste minimisation for more information.

Climate change mitigation
Resource efficiency and waste minimisation


Greenroads sustainability rating scheme was one of a suite of tools that NZTA adopted to drive, measure and recognise sustainability performance on our high-value projects.

The use of the Greenroads sustainability rating scheme has now been superseded by the ISC sustainability rating scheme and NZTA environmental policies and guidelines.

Minga Bluff and Pūhoi to Warkworth completed Greenroads sustainability certification, and Transmission Gully completed a silver pilot sustainability rating.


Our policy on sustainability rating can be found in:



Resources and tools

Technical manuals are available to NZTA project teams. Contact

Further information

For further information contact, the sustainability manager in your project team, or ISC.