NABERS (National Australian Built Environment Rating System) is Australia's primary framework for measuring and comparing the environmental performance of commercial buildings. It rates buildings from 1 to 6 stars across energy, water, waste and indoor environment quality, with ratings based on 12 months of verified operational data rather than design intent. In 2026, NABERS is more commercially significant than ever: the Australian government now requires a minimum 5.5-star NABERS Energy rating for new Commonwealth office leases, rising to 6.0 stars from July 2026, and the July 2025 benchmark methodology changes have shifted ratings for up to 70% of rated office buildings nationwide.
Below we answer many of the initial questions that you’re likely to have regarding NABERS ratings for buildings, the benefits and most importantly how you can begin to improve a buildings rating. You can skip to a specific question by clicking on it below:
The NABERS rating system explained
What are the NABERS rating types?
How do you get a NABERS rating?
How is the NABERS rating calculated?
2025 NABERS methodology update
How can you improve your NABERS rating?
What are the benefits of having a good NABERS rating?
How can I estimate my NABERS rating?
The NABERS rating system explained
NABERS aims to provide a simple, reliable, and comparable sustainability measurement across building sectors such as hotels, shopping centres, apartments, offices, and data centres.
Helping building owners accurately measure, understand, and communicate the environmental performance of buildings, the NABERS system identifies areas for cost savings and future improvements – paving the way for improved financial growth. NABERS claim their customers have saved an average of 30-40% on their energy over 10 years.
The program, which started in Australia in 1998 and expanded to New Zealand in 2012 and the UK in 2020 (they’ve also conducted pilot certifications for buildings in India in 2015, and later Hong Kong and Indonesia in 2017) can also provide that all important competitive factor.
How so? By providing an effective industry benchmarking tool, the system enables building owners to provide potential tenants with independent comparisons to the environmental performance of other similar buildings.
At CIM, we specialise in providing real time access to reliable building information thereby allowing you to make accurate decisions resulting in peak building management performance. These factors are also vital in calculating and optimising your NABERS rating – a process we are skilled and experienced in assisting with.
What is a NABERS rating?
NABERS measures the energy efficiency, water usage, waste management and indoor environment quality of a building or tenancy and its impact on the environment.
Much like the efficiency star ratings that come standard with a new fridge or washing machine, NABERS provides a “star” rating from one to six stars for building efficiency across each of these areas.
As mentioned, this easily digestible rating system helps building owners understand their building’s performance compared to similar buildings – while providing a benchmark for progress and identifying areas for savings and improvements.
NABERS has also partnered with Climate Active to provide a Carbon Neutral certification, another way the program has helped building owners accurately communicate the environmental performance and progress of their buildings to potential tenants.
These ratings are valid for 12 months, the annual model ensuring ratings represent a building or workplace’s current operational performance.
What are the NABERS rating types?
NABERS provides several types of ratings to assess the environmental performance of buildings, including:
NABERS Water
NABERS Water measures the water usage within a building, focusing on conservation and management practices. It helps building owners and managers identify how much water their buildings consume and provides insights into areas where water usage can be reduced, ultimately saving costs and contributing to environmental sustainability.
NABERS Energy
NABERS Energy assesses the energy efficiency of a building and its impact on greenhouse gas emissions. This rating helps to identify the building's energy consumption patterns, benchmark against similar buildings, and find opportunities to reduce energy use and carbon footprint, leading to operational savings and environmental benefits.
NABERS Waste
NABERS Waste evaluates waste management and reduction practices within a building, aiming to improve recycling rates and minimize contributions to landfills. This rating encourages buildings to adopt more sustainable waste management practices, reducing environmental impact and promoting a circular economy.
NABERS Indoor Environment
NABERS Indoor Environment reviews the quality of the indoor environment, focusing on air quality, lighting, temperature, and humidity. This rating is crucial for occupant comfort and health, as it impacts productivity and wellbeing. Buildings with high indoor environment ratings are more attractive to tenants who prioritize employee health and satisfaction.
NABERS Renewable Energy Indicator
The NABERS Renewable Energy Indicator showcases the extent to which a building uses renewable energy in its overall energy consumption. It highlights buildings that are committed to using clean energy sources, reducing reliance on fossil fuels, and supporting the transition to a sustainable energy future.
NABERS Climate Active Carbon Neutral Certification
Buildings that achieve a NABERS Energy rating of 4 stars or above and use carbon offsets to cancel their emissions can obtain the Climate Active Carbon Neutral Certification. This certification recognizes buildings that have achieved carbon neutrality in their operations, demonstrating a commitment to environmental leadership and action against climate change. Buildings can also opt to use renewable energy for their stationary energy consumption instead of carbon offsets, further enhancing their sustainability credentials.
How to get a NABERS rating: The assessment process
Only NABERS Accredited Assessors can perform certified ratings. Assessors are independent professionals trained and accredited through the NSW Department of Planning, Industry and Environment. They are not employed by NABERS, and their fees are set individually.
What you need to prepare
- 12 months of verified energy data. This means actual utility bills (electricity, gas, and any on-site generation) covering a complete, continuous 12-month period. Estimated bills are not accepted.
- Building area measurements. Net lettable area (NLA) figures, verified to NABERS measurement rules.
- Metering configuration. Confirmation that meters cover the rated space correctly and that sub-metering (if applicable) is compliant.
- Occupancy and operating hours data. The number of occupied hours per week and occupancy levels, used to normalise the rating.
How the process works
- The assessor verifies building readiness: area measurements, meter compliance and energy management system accuracy.
- Verified utility data for the full 12-month period is collected and reviewed.
- An on-site inspection is conducted to validate building configuration and data inputs.
- Data is entered into the NABERS rating tool, which normalises for climate, hours of use and building characteristics, then benchmarks against the national dataset.
- The assessor submits the completed rating to the NABERS Technical Team for audit and certification.
- The certified rating is issued, valid for 12 months.
Timeline and cost
The full process typically takes 4 to 8 weeks from engagement to certified rating. The NABERS National Administrator charges a $770 processing fee; assessor fees vary by building size and complexity but generally range from $2,000 to $5,000+ for a standard commercial office assessment.
How is the NABERS rating calculated?
The journey to obtaining a NABERS rating begins with data—lots of it. Here's a step-by-step breakdown of the calculation process:
- Data Collection: The first step involves gathering detailed information about the building's actual consumption. This includes data on energy usage, water consumption, waste production, and indoor environmental conditions over the past year. For buildings seeking an energy efficiency rating, electricity and gas meter readings play a crucial role.
- Normalization: To ensure fairness and accuracy, NABERS accounts for factors that can influence a building's performance but are beyond control, such as climate variations, hours of operation, and occupancy levels. By normalizing data, the system allows for an apples-to-apples comparison between buildings of different types, sizes, and locations.
- Benchmarking: The normalized data is then compared against a benchmark that represents the performance of similar buildings. This benchmarking process is what sets NABERS apart—it enables the rating to reflect how well a building performs relative to its peers, rather than against an arbitrary standard.
- Rating Scale: NABERS ratings range from 1 to 6 stars. A 1-star rating indicates that a building has considerable room for improvement, while a 6-star rating signifies market-leading performance. The beauty of the NABERS scale is its ability to motivate continuous improvement; even buildings at the higher end of the scale can strive for operational excellence and further environmental benefits.
What's changed: NABERS in 2025-2026
The NABERS landscape has shifted materially over the past 12 months. Three changes in particular affect how buildings are rated and what scores are required.
July 2025 benchmark refresh
NABERS Energy benchmarks were updated in July 2025 to integrate the 2024 National Greenhouse Accounts (NGA) emission factors, the first refresh since 2021. The practical effect: as Australia's electricity grid has decarbonised (with increasing renewable energy penetration), the relative emissions benefit of using electricity over gas has grown. Buildings that rely heavily on gas for heating or hot water now receive a lower star rating at the same consumption levels.
The impact is significant. Knight Frank analysis found that nearly 70% of NABERS-rated office buildings across Australia could see their energy rating fall, with Victoria (where 90% of rated stock uses gas) and South Australia (89%) most exposed. NABERS itself notes that fewer than 1% of rated buildings will see a drop of 0.5 stars or more in the first year, but the cumulative effect will grow: buildings using gas can expect reductions of approximately 0.5 stars from 2025 and up to 1 full star by 2030 as further benchmark refreshes take effect.
Separately, the NABERS Energy with GreenPower result has been discontinued from July 2025. The Renewable Energy Indicator (REI) replaces it as the recognised method for demonstrating on-site or off-site renewable energy contributions.
Government lease requirements are tightening
The Australian Commonwealth is using its purchasing power to drive higher NABERS performance across the office market:
- From July 2025: All new Commonwealth office leases for 4+ years over 1,000 m2 of net lettable area must hold and maintain a minimum 5.5-star NABERS Energy rating for both base building and tenancy. Mandatory Green Lease Schedules and EV charging facilities are also required.
- From July 2026: All new government office leases must achieve 6.0 NABERS Energy stars and be all-electric, including heating, cooling and water heating systems (excluding backup generation).
- From January 2040: Commonwealth entities are urged to exclusively lease or own all-electric office spaces.
- New builds and purchases: Commonwealth contracts involving purchase or construction of office space exceeding $15 million require a 6-star NABERS Energy rating.
As of late 2024, only 56% of buildings fully occupied by Commonwealth entities in Canberra held a 5.5+ star rating. The gap between current performance and the incoming 6.0-star requirement represents a major driver of HVAC upgrades, electrification projects and analytics investment across the government-leased office portfolio.
Looking Ahead to 2030: Energy-Based Metrics
NABERS has signalled a fundamental shift in how ratings will be calculated by 2030. As state electricity grids continue to decarbonise, traditional emissions-based ratings risk losing their meaning. The preferred scenario, based on stakeholder consultation, is a nationwide shift to energy-based metrics that treat electricity and gas equally in kWh, without applying emissions conversions. This would refocus ratings on actual energy efficiency rather than fuel-source emissions, and represents the most significant methodological change since the system's inception.
How can you improve your rating?
We specialise in providing real time access to reliable building information. Buildings are a rich source of data – if you have the systems in place to capture it and put it to work. We have advanced building analytics software that analyses existing building performance, via your building management system, to show where you can make energy efficiency improvements.
Our PEAK Platform software allows you to pinpoint building faults and inefficiencies in real time enabling you to resolve issues quickly and satisfactorily. Ultimately, our platform helps you make accurate decisions resulting in peak building management performance.
PEAK also captures critical NABERS data in real time and continually provides data-driven insights based on the NABERS assessment criteria to help you significantly improve your NABERS ratings. For example, PEAK functions as an HVAC monitoring system, gauging your building's HVAC components in real-time and highlighting faults when they occur.
Our experience speaks for itself. CIM and the Kyko Group were able to increase the NABERS star rating by four stars in three years for their building at 99 Elizabeth Street, Sydney, which for Bill Jenkings, director of the Kyko Group, was an outstanding effort.
“In terms of the quantum reduction in energy consumption, CIM’s PEAK platform has exceeded our expectations,” Jenkings says. “At this site, energy consumption has been reduced by 15%. Our indicative NABERS rating was 1.5 stars on this building and we were targeting 4.5 stars and with CIM’s help, we were able to achieve 5.5 stars.”
Is NABERS compulsory?
The NABERS energy rating system is required for all new buildings over 1,000 square metres and buildings that are up for sale or lease.
Rules and regulations aside, attaining a NABERS rating indicates to your peers that you are serious about reducing carbon dioxide emissions. These emissions are mostly caused by large scale heating, ventilation and air conditioning (HVAC) systems used to maintain building comfort.
NABERS industry standing is in part due to the team behind it. While managed by DPIE, the operation of NABERS is overseen by a national steering committee comprised of all State and Territory representatives, and the Commonwealth Government. These government members have voting rights within the committee.
The NABERS steering committee is also made up of non-voting stakeholder members from bodies representing the wide range of NABERS stakeholders.
The scope of mandatory NABERS disclosure is also set to expand significantly. In October 2025, the Australian Government released a roadmap to extend the Commercial Building Disclosure (CBD) program beyond office buildings to hotels and other commercial building types by 2030, backed by $20 million in federal funding.
What is a good NABERS rating?
The maximum rating a building can achieve is six stars - and this is not easy to achieve. A six-star rating indicates a market leading performance, with half the greenhouse gas emissions or water use of a five-star building. There are currently only 256 buildings in Australia with a six star rating.
Conversely, a one star rating means the building is performing well below average and has lots of scope for improvement. NABERS describes each star ratings as follows:
- One Star: Indicates poor performance, much lower than the average Australian building.
- Two and Three Stars: Represent performance that is below average to average.
- Four Stars: Signifies performance that is above average.
- Five Stars: Denotes excellent performance, well above the average.
- Six Stars: Represents market-leading performance, indicating that a building is among the most efficient and sustainable.
According to the NABERS 2020/21 annual report, more than 70% of NABERS rated buildings are 4 star or above.
What are the benefits of having a good NABERS rating?
There are significant benefits associated with obtaining a high NABERS rating. Here’s an outline of some:
- Increased asset valuation: As energy efficiency is increasingly valued by buyers, a high NABERS rating can enhance the value of your property
- Cost savings: The implementation of energy and water efficiency measures significantly reduces operational costs, as energy-efficient buildings experience lower utility costs and long-term savings.
- Improved tenant satisfaction and retention: A high NABERS rating translates to a comfortable and healthy working environment, which improves tenant satisfaction and productivity. With a positive tenant experience, lease renewals and tenant loyalty are increased.
- Increased marketability: Properties with a high NABERS rating have a competitive edge. A high rating validates your property’s environmental performance, leading to higher occupancy rates, reduced vacancies and increased rental income. These properties are desirable to both tenants and investors.
How can I estimate my NABERS rating?
Keen to see how your building may fare from a NABERS assessment? You can log on and use the NABERS rating calculator to get an indication of how your building or tenancy is performing – though do note this cannot be promoted or published.
The first step is to answer a few basic details such as what type of rating you would like to estimate – the options including water, energy, waste or indoor environment. You can then select from the type of building and its postcode.
Follow the prompts and the NABERS rating calculator will provide an indication to your buildings performance.
Do note while you can use the online 'self-assessment' tool, however, you cannot promote these results - only ratings that have been certified by the NABERS national administrator can be promoted using the NABERS.
How long does a rating last?
A NABERS rating lasts 12 months, however, this doesn’t mean you can’t attain the maximum rating possible. The higher the rating, the more responsible your tenants and your peers will rate you. Attaining the maximum rating possible, should be a priority for your business and building.
Manual Tracking vs Real-Time NABERS Estimation
A certified NABERS rating is a point-in-time snapshot based on the previous 12 months of energy data. It tells you where your building was, not where it is heading. For most of the year, building owners and operators are flying blind between annual ratings.
The manual approach
Traditionally, tracking NABERS performance between certified ratings means manually collecting monthly utility bills, entering data into spreadsheets, applying normalisation factors and estimating where the rating might land. This approach has several limitations:
- Lag. By the time utility bills arrive, are verified and entered, the data can be 4 to 8 weeks old. Problems that developed in January may not surface until March.
- No granularity. Monthly utility data cannot tell you which systems are driving changes in performance. A drop in estimated rating could be caused by a faulty chiller, an HVAC schedule override, or a seasonal load shift, and the spreadsheet cannot distinguish between them.
- Error-prone. Manual data entry, inconsistent normalisation and ad hoc calculation methods introduce variability that erodes confidence in the estimate.
- Reactive, not proactive. By the time a manual estimate flags a problem, weeks or months of suboptimal performance have already been locked into the next rating period.
The real-time approach
Building analytics platforms that integrate directly with the NABERS API change the dynamic entirely. Instead of quarterly spreadsheet reviews, building teams get:
- Monthly estimated ratings at decimal-level precision, updated automatically as consumption data flows in. A building tracking at 5.3 stars in February that slips to 5.1 by April triggers an immediate investigation rather than a surprise at the next certified rating.
- System-level diagnostics. Because analytics platforms monitor BMS data alongside energy consumption, they can attribute rating changes to specific systems: an AHU running outside hours, a boiler cycling inefficiently, or cooling demand spiking due to a controls fault.
- Scenario modelling. Operators can model the rating impact of proposed changes (tightening HVAC schedules, adjusting setpoints, switching fuel sources) before committing capital or making operational changes.
- Portfolio-level visibility. For organisations managing multiple buildings, real-time tracking across sites enables prioritisation: focus retrofit spend on the buildings closest to a compliance threshold rather than spreading it evenly.
The difference is analogous to checking your bank balance once a year versus having a live dashboard. Both give you a number, but only one lets you act in time.
Tracking your NABERS rating in a spreadsheet? See how CIM's PEAK Platform delivers monthly NABERS estimates at decimal-level precision, with scenario modelling and portfolio dashboards built in. Book a demo or watch a demo.
NABERS in New Zealand: NABERSNZ
New Zealand operates its own adaptation of the NABERS framework through NABERSNZ, licensed to the Energy Efficiency and Conservation Authority (EECA) and administered by the New Zealand Green Building Council (NZGBC). The system uses the same 0 to 6 star scale and offers three rating types:
- Base building rating: Measures the energy performance of core building services (lifts, common area lighting, air conditioning, ventilation).
- Tenancy rating: Measures energy use within floors or areas occupied exclusively by a single tenant.
- Whole building rating: Combines base building and tenancy performance into a single score.
Government requirements
The New Zealand government has mandated that all government offices above 2,000 m2 must hold a base building rating by December 2025. For new government leases and lease renewals, a minimum 4-star rating is required. New government build projects must achieve a minimum 5 stars.
Adoption status
NABERSNZ has issued 175 ratings to date, covering approximately 1.7 million square metres, or roughly 10% of New Zealand's total commercial floor space. EECA renewed the NABERSNZ programme for a further three years, signalling continued commitment to expanding coverage.
For building owners operating across both Australia and New Zealand, the shared NABERS methodology means that analytics platforms configured for Australian NABERS tracking can support NABERSNZ performance monitoring with minimal additional setup.
CIM's new NABERS API
We recently announced that the NABERS API is now integrated into our PEAK Platform, unlocking new opportunities for automated NABERS tracking and performance insights. Through the integration, CIM can directly access NABERS rating algorithms and historical rating data, helping reduce manual data handling and streamline rating workflows. It also enables real-time rating calculations and improved benchmarking directly within our NABERS dashboards.
As one of the world’s leading performance-based building rating systems, NABERS plays a critical role in how building performance is measured and managed. Integrating the NABERS API helps bring those insights closer to day-to-day performance tracking and data-driven decision making.
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CIM's PEAK Platform is a best-in-class building analytics and property operations software, improving efficiency, sustainability, and tenant comfort across property portfolios. Discover more by watching a demo.
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