If you own or manage a commercial building in Australia, 2026 is not the year to be vague about your NABERS rating. The July 2025 benchmark update has already shifted ratings for up to 70% of Australian office buildings. From July 2026, all new Commonwealth office leases must achieve 6.0 stars and be all-electric.
Whether you are chasing a government tenant, preparing for a lease renewal, or simply trying to understand where your building sits, this guide covers how the system works, what has changed, and what you can actually do to improve your score.
What Is the NABERS Rating System?
What is NABERS rating in plain terms? NABERS stands for the National Australian Built Environment Rating System. It measures the actual operational performance of existing buildings across energy, water, waste, and indoor environment quality. Unlike design-based systems, it uses 12 months of verified real consumption data from utility bills and on-site measurements. The result is a star rating from 1 to 6 that reflects how the building actually performs, not how it was intended to perform on paper.
The NABERS building rating system covers offices, hotels, shopping centres, data centres, and residential buildings. Ratings can be issued for the base building, the whole building, or an individual tenancy.
| Star Rating | What It Means |
| 1 star | Well below average performance |
| 2 stars | Below average |
| 3 stars | Average market performance |
| 4 stars | Above average |
| 5 stars | Excellent performance |
| 6 stars | Market-leading, world-class performance |
Three stars is the market average. It is a reasonable starting point, but given where government requirements are heading, it is increasingly not enough.
Which Buildings Need a NABERS Rating in Australia?
NABERS rating Australia applies across a wide range of building types. Under the Commercial Building Disclosure scheme, office buildings over 1,000 square metres must disclose their NABERS Energy rating whenever the space is sold or leased. That is a legal requirement, not a voluntary one.
Buildings that require or commonly pursue a NABERS rating:
- Commercial office buildings over 1,000 sqm — mandatory CBD disclosure
- Data centres supplying Commonwealth government services — 5.0-star minimum required
- Hotels seeking government procurement eligibility
- Shopping centres pursuing ESG credentials and investor reporting
- Residential buildings seeking sustainability market differentiation
What Changed in 2025 and 2026?
This is the section most building owners need to read carefully. Three specific changes have materially shifted the NABERS landscape.
July 2025 Benchmark Update
NABERS updated its energy benchmarks in July 2025 to incorporate the 2024 National Greenhouse Accounts emission factors. This was the first refresh since 2021. The practical effect is significant. As Australia’s electricity grid decarbonizes, electricity is now relatively cleaner compared to gas. Buildings that rely heavily on gas for heating, hot water, or cooling now receive a lower NABERS energy rating at exactly the same consumption levels as before.
Knight Frank analysis found that nearly 70% of NABERS-rated office buildings across Australia could see their energy rating fall. Victoria, where 90% of rated stock uses gas, and South Australia at 89%, are the most exposed states.
New Commonwealth Government Requirements
The Australian Government has used its procurement power to drive higher performance across the office market. The new requirements are specific and binding.
| Timeline | Requirement |
| From July 2025 | Minimum 5.5-star NABERS Energy for new Commonwealth office leases over 1,000 sqm lasting 4+ years |
| From July 2026 | Minimum 6.0 stars required, all-electric buildings only |
| From January 2040 | Commonwealth entities to exclusively lease or own all-electric offices |
As of late 2024, only 56% of buildings fully occupied by Commonwealth entities in Canberra held a 5.5-star rating or above. The gap between where most buildings sit and where government requirements are heading is real and closing fast.
LED Lighting Regulations from March 2026
The Greenhouse and Energy Minimum Standards LED Lamps Determination 2025 commenced on 3 March 2026. This introduces regulated requirements for LED lamps and directly affects NABERS energy consumption calculations. Lighting efficiency, zoning controls, and after-hours management all feed into the rating outcome. Getting these details right matters more now than it did even 12 months ago.
How the NABERS Assessment Process Works
The NABERS star rating system follows a structured four-step process. Every rating must be conducted by a NABERS accredited assessor — someone who has completed technical training, theoretical and practical exams, and been certified by the NSW Office of Environment and Heritage.
The four steps to obtaining a NABERS rating:
- Engage a NABERS-accredited assessor
- Site visit, data collection, and rating calculations completed by the assessor
- Rating application submitted to the NABERS national administrator
- Certificate issued upon successful review and verification
A few practical things worth knowing before you start:
- Certificates are valid for 12 months and must be renewed annually using the most recent 12 months of consumption data
- Typical completion time is 6 to 8 weeks from engagement
- You will need at least 12 months of verified utility bills and consumption records ready before the assessor begins
- At least one site visit is required for every rating
How to Improve Your NABERS Energy Score
Given the 2025 benchmark changes, improving your NABERS energy score is no longer just about reducing total consumption. It is also about what energy sources you are using. These are the four areas that deliver the most meaningful improvement in 2026.
Switch from Gas to Electric Systems
This is the single most impactful change available to most buildings right now. The July 2025 benchmark update has made gas a direct liability to your NABERS energy efficiency rating.
Buildings still using gas for heating, cooling, or hot water are facing ongoing rating pressure as the grid continues to decarbonize. Electrifying HVAC systems and hot water heaters removes that exposure and positions the building well ahead of the 2030 benchmark changes that NABERS has already flagged are coming.
Upgrade Lighting Controls Properly
LED upgrades alone are not enough. Proper zoning, sensible after-hours setbacks, and occupancy sensors that match real usage patterns reduce kilowatt-hour consumption and lower cooling loads from residual heat.
The metering setup also matters. If the metering cannot cleanly capture the change in lighting consumption, the rating does not reflect the improvement. Getting this right before the assessment, not after, is the approach that produces reliable results.
Monitor Consumption Throughout the Year
Waiting for the annual assessment to identify problems is the most expensive approach. Inefficiencies that run for six months before discovery affect 12 months of rating data. Real-time monitoring identifies issues as they occur and gives building managers time to correct them before they influence the formal assessment outcome.
Approach GreenPower Carefully
NABERS is actively phasing out GreenPower as a rating improvement tool. The introduction of the Renewable Energy Indicator means the long-term pathway is all-electric buildings powered by a decarbonizing grid rather than offset purchases.
Buildings planning significant capital expenditure should factor this direction into procurement decisions now, rather than after the next benchmark update.
Getting Your NABERS Rating Right in 2026
The NABERS building rating system is more demanding in 2026 than it was two years ago. Benchmarks shifted in July 2025, government requirements tightened, and buildings relying on gas are already feeling the pressure.
The NABERS star rating system rewards consistent year-round management, not a scramble before the annual assessment. Tracking consumption continuously, electrifying key systems, and working with an experienced accredited assessor are what actually move the needle.
Eco Certificates has accredited assessors with over 13 years of experience and a 100% approval rate across all assessments delivered.
Contact Eco Certificates on 1300 16 24 36 or request a quote online.
