Green Star NZ - Embodied Carbon

Thank you for your feedback on the first draft guidance to the building and construction sector on the calculation of embodied carbon, paving the way for industry to reduce emissions from building materials and supplies.

The consultation period is now closed and we're working through the detailed feedback to be able to release the final version as soon as possible. If you'd like an update in the meantime, please contact Brad Crowley (  

Read on for more information on the approach so far.

The building and construction sector across Aotearoa New Zealand is active in our commitment to reducing our contribution to carbon emissions. The amount of support from the private and public sectors to better understand, calculate, measure and manage upfront and whole-of-life embodied carbon is heartening for all who are getting to grips and taking action on climate change.


Green Star NZ - an approach to embodied carbon


The New Zealand Green Building Council is committed to delivering on our vision for sustainable, green homes and buildings for happier, healthier New Zealanders. We are regularly approached by members and the wider sector looking for guidance on carbon reduction through Green Star and other analysis.

Over the past few months, we've partnered with thinkstep anz and a small group from across the industry to help establish a robust embodied carbon calculator. Through these discussions we've identified a need to develop an industry-wide approach to support the definition, scope and calculation of embodied carbon. The benefit should be the closest possible comparison of designs across buildings and projects no matter what calculator is used.

Application to Green Star Design & As Built NZ v1.1

Green Star Design & As Built NZ v1.1 awards points based on a reduction in upfront carbon. A minimum reduction in upfront carbon of 10% is required to achieve a Green Star rating. In addition, projects must demonstrate that whole-of-life embodied carbon is no higher than a defined maximum to show that the carbon footprint is not simply shifted from the first stage of the buildings life to the later stages.


Documents as drafted


The draft document Green Star NZ Embodied Carbon Methodology describes the underlying methodology behind the calculations within the Embodied Carbon Calculator. It's been developed to enable organisations to apply the same methodology within their own tools and calculators. The how-to guide on the use and application of the Calculator is outlined within the separate Embodied Carbon Calculator Guide (the Calculator Guide). 

The Calculator, Guide, and Methodology are intended to align with MBIE's Building for Climate Change (BfCC) programme (MBIE, 2022), even though BfCC is not yet final at the time of publication.

The resources published for consultation are now under review to incorporate industry feedback: 

  1. Embodied Carbon Calculator
  2. Embodied Carbon Calculator Guide - supporting navigation of the Embodied Carbon Calculator
  3. Embodied Carbon Methodology Document - to assist projects using other embodied carbon calculators with the aim of providing consistency in parameters and assumptions, where possible, across all calculators.

If you would like to discuss or request an update, please contact