Energy for Offices measures the energy efficiency of an operational office building based on metered data and rates its performance.


Offices can be rated in three ways: Base Building, Tenancy and Whole Building ratings. The energy rating works by comparing the energy consumption of a building against a set of benchmarks. These benchmarks have been developed using actual performance data from offices in the UK to set the median and the rating considers both location and occupancy.

NABERS UK Version 2.0


There are two official documents which explain how a NABERS UK Energy for Offices rating can be calculated :

  • The Rules for Energy for Offices version 2.0 (Base Building, Whole Building and Tenancy)
  • The Rules Metering and Consumption version 2.0 (Base Building, Whole Building and Tenancy)


These are an important reference for Licensed Assessors. The updated version 2.0 (Base building, Whole building and Tenancy) of these rules can be downloaded on the Useful Downloads page.


Any ratings performed using the previous versions of the Rules (see below) must apply for certification by 31st July 2023.  Any Ratings using these Rules documents that are submitted after this date will be rejected.

  • NABERS UK The Rules – Energy for Offices v1.2 (base building only)
  • NABERS UK The Rules – Metering and Consumption v1.1 (base building only)

Office buildings can be rated in three ways:



Buildings can be rated based on their central services like heating and cooling systems, lifts and lobby lighting.




Enables energy used by the tenant to be rated, typically for lighting and power, plus special tenancy requirements or local a/c.




Provides assessment of energy used by office tenancies and by Base Building services to lettable and common spaces.


The Energy for Offices Registration Process


The infographic below explains the Energy for Offices Registration Process for developers interested in obtaining an energy rating for their operational building. Once a building has received its NABERS Energy Rating it will be listed on Greenbooklive.

Is my building eligible for a NABERS Rating?


A building is considered eligible for a NABERS rating if all of the eligibility criteria detailed below are met:

a) Building type: during the rating period, the building or part of the building was used as an office, or, if unoccupied, capable of being used as an office.

Note 1: Purpose-built educational buildings (e.g. a school or non-office buildings on university campuses) or medical centre buildings are not considered educational office facilities or medical office facilities as they are not a tenancy within a commercial office building. Therefore, they cannot be assessed for a NABERS Energy for Offices rating.

b) Building consumption data: less than 80 % of the building’s total office NIA has been excluded due to lack of consumption data using the method described in Section 4.5.5 of the Rules for Energy for Offices.

c) Building energy coverage: the minimum energy coverage is met, as described in Chapter 6.

d) New buildings and major refurbishments: new buildings or buildings undertaking major refurbishments are eligible for a NABERS rating as soon as 12 months of a rating period can be completed. In these cases, the rating period can start as soon as one of the following conditions is met (whichever occurs first):
1) 75% of the office NIA is occupied by tenants; or
2) It has been two years since the certificate of completion was issued.

What if my building has had high levels of vacancy e.g. due to COVID-19?
Occupancy levels are only relevant for new buildings or major refurbishments, so essentially operational buildings with high levels of vacancy are eligible for a NABERS rating to be conducted. Please note however, there may be a difference in subsequent ratings if occupancy levels go back to pre-pandemic numbers. In Australia, some buildings have received higher ratings during that low occupancy phase, however some haven’t changed significantly as plant operations continue to run regardless of occupancy.

Benefits of a NABERS Energy rating



NABERS Energy ratings form the basis of a robust sustainability strategy. They provide a fair benchmark for a building’s energy efficiency, enabling comparison across the industry.

Validate and communicate

NABERS provides cost-effective, high-trust and independent validation of energy data, ensuring confidence in reporting it publicly and communicating it simply.

Track and improve

NABERS star ratings are an essential framework for annual reporting and sustainability strategies. With annual ratings, performance improvements and reduced energy and emissions can be delivered over time.

Competitive edge

Having a building that has a lower environmental impact, lower running costs and being able to communicate that simply and with confidence gives building owners the competitive advantage with prospective investors and occupiers.

How to get a NABERS Energy rating


To get a NABERS Energy rating you need a Licensed Assessor to undertake an assessment of your building.

Training is now available, and a Licensing pathway has been developed and the first Licensed Assessors have been receiving their Licenses since September 2021.
To receive a rating on your project you must contact a NABERS UK Licensed Assessor.


Estimate your NABERS rating


Two calculators are available for you to explore what star rating your building could achieve; a simple calculator and a reverse calculator. These are available in a single download below.

  • Use the simple calculator to get an idea of the NABERS rating your building may be able to achieve. Input building details and energy consumption data to generate a star rating.
  • Use the reverse calculator to estimate maximum energy use for a given star rating. Enter a target rating plus building details, energy consumption types and proportions. This will generate maximum allowable energy consumption.


Results are an indication only and may not be promoted or published.

Download both calculators here and select a tab. For information on pricing please see our pricing page.

NABERS UK offers private ratings


NABERS UK offers third party certification that can give owners/clients confidence in their ratings, and transparency of their achievements to their stakeholders that will ready them for disclosure requirements in the future.

However, it is also a tool to help inform the sustainability journey of an office building, and there may be some hesitation from clients to publish a rating.

NABERS UK is committed to supporting all offices on their sustainability journey. For this reason, whilst publicly sharing ratings is strongly encouraged, private ratings are also available.

Downloads & Publications


All downloads are available on the ‘Useful Downloads‘ page.