Green Star Technical Clarification Rulings
Technical Clarifications for Green Star represent our answers to Technical Questions submitted by projects, and provide further guidance and reference to others. The list is regularly updated.
There are two types of Technical Clarifications listed in the table below:
General Clarifications
These are extensions to the guidance provided in the Submission Guidelines. They clarify and sometimes supersede the original Credit Criteria or
Compliance Requirements. General Clarifications set precedent for future project teams to follow. Should a project team wish to apply a general clarification to its project, there is no requirement for further Technical Questions to be submitted. NZGBC Assessors will also use them as precedents to assess submissions.
Project Specific Clarifications
These are published as references for other projects but, unlike General Clarifications, they do not set precedent. They often relate to special
situations where multiple prerequisites exist for a particular project and are less likely to reoccur to another project. Therefore, rulings set for Project Specific Clarifications are often conditional and will likely vary for other projects. Each project still needs to submit its own Technical Questions and provides evidence relating to its own building in order to have a similar ruling approved for that specific building.
Should you wish to apply any Technical Clarification for legacy rating tools to your projects, please submit a Technical Question to the NZGBC to
explain why and how it applies. You can access the online Technical Question form here
| Technical Question Title | Tool Version | Date Released | Credit Name | Sub-credit Name | TC Link |
|---|---|---|---|---|---|
| NZ Steel Electric Arc Furnace EPD | Green Star Buildings NZ, DABv1.1, DABv1 | December 2025 | 19 - Life Cycle Assessment/Impacts, 20 - Responsible Building Materials, 21 - Sustainable Products, 6 - Responsible Structure, 21 - Upfront Carbon Emissions, 26 - Life Cycle Impacts | Link | |
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Approved Ruling: Updated September 2026. This is to clarify the use of the EPD’s during the NZ Steel transition from oxygen furnace (KOBM) to Electric Arc Furnace (EAF): Hot commissioning (producing batches of steel) of the new EAF began August 2026, and there will likely be a period of 3 months where both the old process (KOBM) and new process (EAF) co-exist. The EAF will be ramping up as the KOBM ramps down. During that time, NZ Steel will be able to provide low carbon steel manufactured from 100% scrap (DCRB) for which they have a separate EPD. At some point, likely by late 2026, the old process (KOBM) will be fully retired and the new process (EAF) will be the only steelmaking route at NZ Steel. During the transition, both processes will be operating for a period of time which gives projects the option to use three different types of steel and their associated EPD: - Projects should by default use NZ Steel’s old EPDs until the old process (KOBM) is officially shut down, and the old-steel-stock is worked through / substantially consumed, unless specifying one of the below 2 other options. - Any low-carbon steel (made from 100% scrap - DCRB) purchased at any point could use the new lower-carbon EAF EPD's. (These are new products with their own SKUs and separate heat numbers which are fully traceable, so there is no risk of confusion between old and new products.) - Projects who want to use steel from the EAF (but not the separate low-carbon DCRB product made from 100% scrap) before the old process is fully shut down could use it in a project-by-project basis, with evidence given by NZ Steel, who can supply a letter indicating that the steel supplied (covering named heat numbers) was made via the EAF pathway and therefore show traceability and that the new EPDs apply. Once the old process (KOBM) is shut down, all steel would transition to the new EPDs and the old EPDs would be retired, similar to how standard EPD updates occur. To reduce the risk of allocating lower emissions to the higher emission process, the following date is when the new EAF EPD’s will update to replace existing EPD’s / default values for a Green Star Project where veracity of claimed performance is very important. The dates apply to the processed steel products: Approximately 6 months after EAF hot commissioning began after which the EAF EPD values can be taken and old EPD’s retired. This is expected to be End of February 2027, with the exact date to be confirmed by 31/10/2026. This timing was based on evidence provided that demonstrates when the EAF-made steel volumes will have flushed through over 90% of KOBM stock (including new stock made during the transition) in both steel manufacturer and steel processor inventories. |
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