With the increasing significance of sustainability and environmental responsibility, different rating systems have been developed to assess the environmental performance of buildings.
Australia has two leading rating systems known as Green Star and NABERS rating. (National Australian Built Environment Rating System).
Both aim to promote sustainable practices in the built environment, but they differ significantly in focus, methodology, and application. This blog will discuss these differences in detail.
Introduction to Green Star and NABERS Rating
Green Star is a nationwide comprehensive voluntary environmental rating system that evaluates buildings’ environmental impacts, fit-outs, and communities.
It is developed by the Green Building Council of Australia (GBCA). It assesses projects’ sustainability features across nine categories. These include:
- management,
- indoor environment quality (IEQ),
- energy,
- transport,
- water,
- materials,
- land usage and ecology,
- emissions, and
- innovation.
On the other hand, NABERS is a national rating system that measures how well buildings perform environmentally during their operation.
NABERS certification emphasises key aspects such as:
- energy efficiency,
- water usage,
- waste management, and
- indoor comfort.
Such ratings give an independent evaluation of how a building manages its resources compared to other similar properties.
Key Differences Between Green Star and NABERS Rating
Green Star and NABERS ratings are fundamental to the promotion of sustainable building practices within Australia. However, they are diverse regarding their scope, focus, methodology, assessment processes, and applications. Below is an elaborate look at those:
Scope and Focus
Green Star
- Comprehensive Evaluation: Evaluation applies to whole projects, including buildings, interiors, communities, etc.
- Lifecycle Approach: It considers the whole lifecycle of a project. The Green Star rating is applicable from design to construction and operation.
- Holistic Assessment: It takes into account several elements like management, indoor air quality, energy conservation initiatives, public transportation access, water-saving technologies, waste disposal practices, land use patterns, installation of solar panels, adaptable heating and ventilation conditioning (HVAC) systems, and more.
NABERS Rating
- Operational Performance: The NABERS rating is focused only on the operational performance of existing buildings.
- Specific Metrics: This measures certain aspects as energy efficiency, water utilisation, waste management and indoor environment quality.
- Annual Snapshot: This provides a performance rating based on data from the previous 12 months. The most common NABERS certification is the NABERS energy rating.
Rating Methodology
Green Star
- Points-Based System: Points are earned by projects for various categories depending on their sustainability. The sum of these points gives the Green Star rating.
- Rating Levels: The ratings go from 1 Star (minimum) to six stars (industry leadership).
- Innovation Points: Extra marks for innovative sustainable practices.
NABERS
- Data-Driven Ratings: The actual performance data collected over the last year is used in this approach.
- Benchmarking: This compares a building’s performance against similar ones found nationwide.
- Star Ratings: A star rating, which ranges from a minimum of 1-star rating to a maximum of 6 stars, shows how well it performs against the standard set by others who have gone before it. The rating scale is the same for NABERS water rating and energy rating.
Assessment Process
Green Star
- Documentation: Each category requires detailed documentation and evidence for assessment purposes.
- Third-Party Verification: Independent, accredited professionals review and verify the documentation provided to them by project teams
- Design and As Built: They may undergo assessments during the design phase or post-construction so as to ensure continued compliance throughout their life cycle
NABERS Rating
- Performance Data: The NABERS rating relies on operational performance data like energy consumption, water use, waste generation and indoor air quality. The data is influenced by human activities within these structures.
- Independent Assessors: To ensure that the data provided is accurate, NABERS-accredited assessors verify them.
- Annual Reassessment: To preserve or update NABERS-rated buildings, they are reassessed every year and receive annual NABERS certification.
Certification and Validity
Green Star
Project-Specific Certifications: The certifications for these projects remain in place indefinitely. There is a possibility that a project can request recertification in order to reflect improvements or changes over time.
Different Kinds of Certifications: These include Green Star – Design & As Built, Green Star – Interiors and Green Star – Communities
NABERS
The NABERS energy rating or water rating has an annual validity period of 12 months. This shows the present capability of the structure.
To maintain or improve their ratings, buildings need to be assessed annually for continuous improvement purposes.
The focus here is on operations that should be continuously improved and monitored.
Application and Use
Green Star
- It is mainly used for new buildings, major refurbishments and large-scale community projects.
- This gives guidance on integrating sustainability into design and construction processes.
- They help to boost green building sales by demonstrating commitment towards sustainability practices.
NABERS Rating
NABERS rating is largely used to assess operational performance enhancements in existing buildings.
It acts as a management tool for building owners/operators seeking to monitor or enhance environmental performance.
Frequently, it is employed for regulatory compliance with government regulations or meeting tenant requirements in terms of sustainability.
Practical Implications
Green Star
- It encourages sustainable practices during the early stages of a project.
- Supports long-term sustainability goals and strategies for new developments
- This promotes healthier indoor environments for occupants who use the building.
NABERS
- The main emphasis here is improving day-to-day operations within buildings.
- NABERS certification fosters energy & water savings, leading to cost reduction measures.
Benefits of Green Star and NABERS Rating
Both rating systems are highly beneficial not only to property owners but also to occupants as well as to society at large:
Green Star
Puts emphasis on sustainable construction methods and designs being adopted.
- Minimises environmental impact associated with developing new properties.
- Healthy internal spaces will be encouraged through this method by keeping the quality of the internal environment at the best levels.
NABERS Rating
- It offers an open evaluation, hence allowing for better comparison.
- Assists in identifying operational areas that need improvements.
- These tools also promote energy and water savings by minimising operating expenses.
Choosing Between Green Star and NABERS
Selection between NABERS and Green Star usually relies on project or building-specific objectives and circumstances.
- For property developers, designers wishful of achieving very high levels of sustainability in new buildings, fit outs, or large scale community projects, it is the ideal rating tool.
- Best suited for owners and managers of buildings who intend to improve performance and demonstrate their sustainability efforts to people concerned.
Conclusion
A clear understanding of key differences between Green Star and NABERS ratings can enable stakeholders to choose the most appropriate system for their particular needs. While Green Star is suitable for new developments and full sustainability assessments, NABERS certification should be chosen by existing structures aiming at improved operation performance. These two are indispensable in advancing a sustainable built environment.