Rating tools

Rating tools are market-based mechanisms that are used throughout the world to endorse and reward buildings that achieve good levels of sustainable features.

The value of a rating is that it clearly communicates to the market what the building has achieved, and helps differentiate it from others. Because they give a clear independent benchmark of a building’s credentials, ratings are often sought and preferred by investors seeking the lower risk and better value of green assets.

Rating tools internationally

Examples of rating tools used globally, are LEED in the US and BREEAM in the United Kingdom.

Green Star, New Zealand’s rating tool for commercial buildings, is based closely on the Australian Green Star, which was developed by the Green Building Council of Australia. The South African Green Building Council also uses a version of Green Star.

Rating tools in New Zealand

In New Zealand the NZGBC runs a range of rating tools, for different purposes and different types of buildings.

Green Star

Green Star applies to commercial building projects including office, education, industrial buildings, and interior fit-outs. We also develop custom Green Star tools for projects that don't easily fit those categories (e.g. a hospital or theatre). Green Star rates projects in nine categories, with ratings ranging from 4 (New Zealand excellence) to 6 (world leadership). In 2014 we reached a milestone with the certification of the 100 th Green Star rating.


Homestar, the tool for home sustainability, rates homes on a scale from 1 to 10. The typical home built only to Building Code would rate around 3 or 4 Homestar. Developments of 6 Homestar and above, denoting better warmth and energy efficiency, are increasingly common. Homestar was developed by NZGBCin partnership with BRANZ, Beacon Pathway and experts in sustainability and building science across government and industry.


NABERSNZ is the energy performance rating tool for New Zealand office buildings. Adapted from the Australian NABERS tool for New Zealand, it is licensed to the Energy Efficiency and Conservation Authority and delivered by NZGBC. NABERSNZ rates the actual energy performance of buildings over 12 months, on a 1 – 6 star scale. It can be applied to base buildings, tenancies or whole buildings.