Commercial Sustainability
Green Star Performance Explained for Existing Commercial Buildings
Green Star Performance is the Green Star pathway focused on existing buildings and their ongoing operational sustainability. Unlike Green Star Buildings, which is used for new buildings and major refurbishments, Green Star Performance looks at how an asset performs in use, how it is managed and how it can continue improving over time.
Short answer
Green Star Performance is a sustainability rating pathway for existing buildings. It helps owners, asset managers and project teams assess operational performance across areas such as energy, emissions, water, waste, indoor environmental quality, management, resilience, nature, social impact and long-term improvement.
What Is Green Star Performance?
Green Star Performance is a Green Star rating tool for existing buildings in operation. It helps building owners and managers understand how a building is performing after it has been built, occupied and operated. This makes it different from design-focused pathways that assess a project before or during construction.
For commercial buildings, this operational focus matters. A building can be well designed but still underperform in use if controls are not tuned, tenants are not engaged, systems are not maintained, data is poor or sustainability management is not embedded into day-to-day operations.
Green Star Performance gives existing assets a structured way to assess operational sustainability, identify improvement opportunities and communicate performance to stakeholders, tenants, investors and portfolio managers.
Who Uses Green Star Performance?
Green Star Performance is most relevant to existing building owners, asset managers, facilities teams, portfolio managers, landlords, investors and organisations that need to understand how their buildings are performing over time.
Green Star Performance may be relevant for:
- Existing commercial office buildings
- Retail centres and mixed-use assets
- Education and university buildings
- Healthcare and civic facilities
- Industrial and logistics buildings
- Commercial campuses and portfolios
- Buildings with ESG or investor reporting requirements
- Assets seeking a pathway toward better operational sustainability
- Owners wanting to improve emissions, waste, water, resilience and wellbeing outcomes
It can be used for individual buildings or as part of a broader portfolio strategy where consistent performance improvement and reporting are important.
How Green Star Performance Differs From Other Green Star Tools
Green Star Performance is one part of the wider Green Star system. The important distinction is that it focuses on existing buildings and operational performance, rather than new design, fitouts or precinct planning.
| Green Star pathway | Typical focus | Simple example |
|---|---|---|
| Green Star Buildings | New buildings and major refurbishments | A new commercial office building |
| Green Star Fitouts | Interior fitout projects | A workplace fitout or tenant interior |
| Green Star Communities | Precincts and masterplanned communities | A mixed-use precinct or commercial campus |
| Green Star Performance | Existing building operations | An operating commercial asset or portfolio |
This distinction matters because the evidence, timing, project team and improvement strategy can be very different. A new building assessment may focus on design and construction decisions, while a performance assessment focuses on how the building is being managed and operated.
Green Star Performance vs NABERS
Green Star Performance and NABERS are often mentioned together because both relate to existing buildings and operational performance. However, they are not the same rating system. NABERS is strongly focused on measured performance across areas such as energy, water, waste and indoor environment. Green Star Performance takes a broader sustainability view of how an existing building is operated and improved.
In practice, NABERS ratings can support the Green Star Performance conversation because measured operational data is valuable. However, Green Star Performance may also consider broader issues such as management systems, resilience, social impact, nature, circular economy and improvement pathways.
NABERS helps measure specific operational performance outcomes. Green Star Performance places existing building operations within a broader sustainability framework.
What About Green Star Performance Criteria and Rating Brackets?
Older Green Star content often focused heavily on criteria and rating brackets. That can be useful, but it can also become outdated quickly as rating tools evolve. For current projects, the safest approach is to check the latest GBCA tool guidance and confirm which version of Green Star Performance applies.
In broad terms, Green Star ratings are commonly expressed through star levels that communicate the level of sustainability performance achieved. However, project teams should avoid relying on old point tables or legacy rating bracket summaries without confirming the current tool version, assessment requirements and transition rules.
When reviewing criteria or rating brackets, check:
- Which version of Green Star Performance applies
- Whether the project is new, already registered or transitioning between versions
- Which operational data is required
- Whether NABERS ratings or other measured performance inputs can contribute
- Which sustainability categories need improvement
- What documentation and evidence will be needed
- How the building or portfolio will maintain performance over time
What Does Green Star Performance Consider?
Green Star Performance looks at existing building operations through a broad sustainability lens. This can include environmental performance, building management, health and wellbeing, resilience, carbon, water, waste, nature, social impact and the systems that support ongoing improvement.
Depending on the pathway, Green Star Performance may connect with:
- Operational energy performance
- Greenhouse gas emissions and net zero pathways
- Water use and waste management
- Indoor environmental quality and occupant wellbeing
- Building management, policies and procedures
- Climate resilience and risk management
- Nature, ecology and site-related outcomes
- Circular economy and fitout waste considerations
- Social impact and stakeholder engagement
- Data quality, reporting and ongoing improvement
The exact criteria and documentation requirements depend on the current rating tool and the building being assessed. This is why early pathway confirmation matters.
Why Existing Buildings Matter
A large part of Australia’s commercial building stock already exists. Improving only new buildings is not enough if existing assets continue to use energy, water and materials inefficiently or fail to adapt to changing climate, tenant and investor expectations.
Green Star Performance helps existing buildings move from one-off sustainability claims toward measurable operational improvement. It can support portfolio planning, ESG reporting, tenant engagement, asset repositioning and long-term performance management.
This makes it especially relevant for owners who want to understand not just how a building was designed, but how it is actually performing in the real world.
Common Improvement Opportunities
Improving Green Star Performance outcomes is usually not about one large upgrade. It is often about a combination of technical, operational and management improvements that make the building perform better over time.
Improvement opportunities may include:
- Energy audits and tuning of building systems
- Improved metering, controls and data quality
- Electrification and fossil fuel reduction planning
- Renewable energy procurement or onsite generation
- Water efficiency upgrades and leak detection
- Waste management, separation and reporting improvements
- Indoor air quality, comfort and occupant experience improvements
- Resilience planning and climate risk review
- Tenant engagement and operational policy improvements
- Better maintenance, commissioning and performance monitoring
What Building Owners Should Check Early
Before pursuing Green Star Performance, building owners and asset managers should confirm the current pathway, the building scope, available data and the relationship with other operational ratings or reporting requirements.
Early questions include:
- Which version of Green Star Performance applies?
- Is the building being assessed individually or as part of a portfolio?
- What operational data is available?
- Does the building already have NABERS ratings?
- What emissions, water, waste or wellbeing targets are being pursued?
- Are there investor, ESG or reporting requirements?
- What management policies and procedures need review?
- What improvement plan will support performance over time?
Why This Matters
Green Star Performance matters because existing buildings are where sustainability ambition meets operational reality. A building’s day-to-day performance depends on systems, management, data, maintenance, tenant behaviour, policies and ongoing improvement. These are not always visible in the original design documents.
For owners and asset managers, the pathway can help make operational sustainability more structured. It can support better evidence, clearer priorities, stronger tenant and investor communication and a more disciplined approach to improvement over time.
For commercial portfolios, this can help turn sustainability from a once-off project into an ongoing asset management strategy.
How Certified Energy Can Help
Certified Energy helps commercial project teams and asset owners understand how Green Star Performance connects with broader sustainability, operational performance and reporting requirements. Depending on the project, this may involve ESD consultancy, NABERS-related support, operational performance review, energy efficiency advice, embodied carbon reporting, lifecycle assessment, daylight modelling or thermal comfort analysis.
Our role is to help clarify what the building needs, what evidence may be required and how performance improvement can be coordinated across technical, operational and reporting requirements.
Assessing an existing commercial building?
Early advice can help identify whether your asset needs Green Star Performance support, NABERS-related advice, operational sustainability review or wider ESD consultancy.
Related Reading
These related pages may help you understand how Green Star Performance connects with existing building operations, NABERS, sustainability reporting and commercial building performance.
Frequently Asked Questions
Green Star Performance
What is Green Star Performance?
Green Star Performance is a Green Star rating tool used to assess the operational sustainability performance of existing buildings. It helps owners and managers understand how an asset is performing in operation across a range of environmental, social and building performance outcomes.
What types of buildings use Green Star Performance?
Green Star Performance can be relevant for existing commercial buildings and portfolios, including offices, retail buildings, education buildings, healthcare facilities, industrial buildings, mixed-use assets and other operating buildings where sustainability performance needs to be assessed.
Is Green Star Performance the same as NABERS?
No. Green Star Performance and NABERS both relate to existing building performance, but they are not the same. NABERS is strongly focused on measured operational performance such as energy, water, waste and indoor environment. Green Star Performance is a broader sustainability rating for existing building operations.
Is Green Star Performance for new buildings?
Green Star Performance is focused on existing building operations. New buildings and major refurbishments are generally considered under Green Star Buildings, while fitout projects may be considered under Green Star Fitouts.
How can an existing building improve Green Star Performance outcomes?
An existing building can improve Green Star Performance outcomes by improving operational energy efficiency, emissions performance, water use, waste management, indoor environmental quality, resilience, management systems, tenant engagement, data quality and ongoing building performance.
