A NABERSNZ rating generally takes six to eight weeks from start to finish. The best way to ensure a timely rating is to keep good records and have all the appropriate data on hand.

Generally a rating application will progress through the following process:

• The client (building owner/manager/tenant) engages an Assessor to carry out a NABERSNZ rating.

• The Assessor compiles data, including a site visit to the building for verification, and input data into the Certified Rating tool.

• The Assessor submits the rating for client authorisation.

• The client reviews and decides whether to proceed with the rating.

• NZGBC receives and registers certification payment.

• NZGBC audits, verifies and certifies the rating.

• The client is notified of certification and receives an electronic Rating Certificate and Rating Report.

The key to a timely and accurate NABERSNZ rating is preparation. You’ll need to make sure you have all the necessary data on hand and readily available for your NABERSNZ Assessor. This will save you time and money and make the process much easier.

Data required for a NABERSNZ Certified Rating:

• Utility bills covering 12 months of energy data

• Up to date survey drawings inline with PCNZ standard

• Hours of occupancy

• Computer counts for tenancy or whole building rating

A free online self-assessment rating is also available to help get an initial idea about how your property might rate and what it will take to achieve a target NABERSNZ Certified Rating. The results of this tool are indicative only, based on the data you submit and should not be taken as a guarantee of achieving a specific star rating or promoted or published.

A rating is conducted by an Assessor in compliance with the NABERSNZ Rules for collecting and using data. In some circumstances your Assessor may require more detailed information to perform your rating application.

Note that submetering is required for tenancy or base building ratings. If there is inadequate submetering, a whole building rating should be performed.

A NABERSNZ rating is just the start of a journey and provides a snapshot of your energy performance for the previous year. Once you know how efficient your premises is compared to your peers, you can start to make improvements ahead of re-rating. Here are some useful tips to save energy use and improve your rating next time:

• Establish an energy management strategy for your company

• Energy monitoring and reporting helps identify areas of inefficient energy use 

• Fine tune and commission to improve current building management systems to efficiently control lighting, heating and cooling system

• Install energy efficient lighting

• Behaviour changes of tenants and employees to take consideration of energy savings (e.g. turn off lights, monitors, appliances when not in use)

• Replace non-energy efficient office appliances

Your NABERSNZ Assessor will be able to provide personalised recommendations based on your current rating

We are seeing a growing number NABERSNZ related clauses as part of new building design agreements and retrofit projects, and there are strong needs from design teams to correctly understand NABERSNZ requirements on sub-metering. NABERSNZ requires tenancy and base building loads to be metered separately. It is recommended that all sub-metering is installed in accordance with the NABERSNZ Rules.  

More broadly, buildings with more efficient systems and renewable energy sources will likely achieve higher ratings. If you are committed to achieving a high NABERSNZ star rating, we would encourage energy efficiency be prioritised early in the design of a new build or fit-out project. 

NABERSNZ looks solely at energy performance, and is used once buildings are occupied and operating for a year or more.

Broadly, Green Star certification considers the design and construction of a building and assesses a range of environmental criteria. Green Star - Performance NZ does consider building operations, however, while NABERSNZ is purely concerned with energy use, Green Star - Performance NZ considers other emissions factors such as waste, water use, use of refrigerants etc. 

Either can rate warehouses but each tool has its advantages, disadvantages, and use cases.

Green Star Performance is able to rate all warehouses, including manufacturing warehouses and workshops using a base building approach if submetering is available. This tool is versatile in that it can rate a single building or a portfolio of buildings, including a portfolio calculator which can simplify the process and make it more cost effective. The benchmarking and normalises in a relatively simple way so is not going reflect the increased energy consumption of conditioned vs non-conditioned spaces.

NABERSNZ Warehouses and Cold Stores can only rate logistics warehouses. This limitation means it cannot be used for manufacturing warehouses or any operation that changes the form of a product. It only rates one building at a time – there is no portfolio approach available. This means each rating will be charged the appropriate certification fee separately. The benchmarking and normalisation behind the NABERSNZ tool is quite sophisticated and can take into account conditioned or non-conditioned spaces to create a fair comparison.

Contact the NZGBC for more information and guidance on the above to suit your situation.