Key Green Building Rating Systems- what systems are used where?

The increased number of green building organisations has lead to an increase in the use of green building rating systems on an international scale. These rating systems include: LEED (USA), BREEAM (UK), Green Star, (Australia) CASBEE (Japan) and Green Star (South Africa). These assessment tools provide projects with a qualitative evaluation of the several benefits of incorporating green practices into developments and measure the overall environmental performance of a building. Furthermore, green rating systems have created a shift in the property industry towards more sustainable and eco-friendly developments.



Leadership in Energy and Environmental Design (LEED) was developed by the US Green Building Council (USGBC) in 2000. LEED is a widely used international standard for assessing buildings according to their sustainability and environmental performance. In addition, LEED has been used as a basis for the development of other markets rating tools worldwide.

LEED was developed with the consideration of several objectives. These objectives include: to create a standard form of measurement for green buildings, to promote innovative and integrated sustainable practices, to recognize and award leadership in green building developments and to promote awareness of the benefits of green building.

Additionally, LEED provides a framework for identifying and incorporating sustainable principles into the design, construction, operation and maintenance of a building . Furthermore, the LEED rating system is not confined to new developments as it also addresses operations and maintenance of existing buildings schools, retail, homes, core-and-shell projects, healthcare facilities, existing buildings, offices neighbourhood development and major renovations.

LEED is divided into five environmental categories: Sustainable Sites, Materials and Resources, Indoor Environmental Quality, Energy and Atmosphere and Water Efficiency. Innovation and Design and Regional priority are two additional categories, in which bonus points can be acquired for a development. All of these categories will be considered when assessing a building and credits will be awarded at each stage. The total amount of credits achieved will determine the performance of a building in terms of sustainability.

LEED is the only rating system, which includes provisions for recertification. In addition, it is also the only system that requires the evaluation of the operations and maintenance of a new building for a specific period.  Therefore, LEED considers sustainability of the operations and maintenance performance of a building after the construction period.

Therefore, LEED creates a common standard of assessment for green design and awards superior green buildings. The achievement of a LEED certification for a building will convey an image of social responsibility to potential clients and tenants and will provide improved performance for the building.


BRE Environmental Assessment Method (BREEAM) was the first building rating system to be formed and was developed in the UK in 1990. It is an assessment tool which measures the sustainability of a building through the achievement of credits based on environmental considerations.

BREEAM provides green buildings with market recognition, it encourages best practice in terms of design, construction, operation and maintenance of a building, it ensures that the environmental standards and legislature are met and it creates awareness of the impact a building has on the environment. BREEAM is applicable to a wide range of building types- these include healthcare, multi-residential, education, courts, prisons and industrial, offices and retail buildings.

BREEAM sets an international benchmark for best practice in sustainable construction, operation and design. In addition, it has become established internationally as the most recognized measure of environmental performance and has had a significant influence in inspiring the development of other international rating systems.

Additionally, BREEAM measures the performance of a building according to several criteria. These categories include: Energy and water use, Pollution, Materials, Ecology, the Internal Environment, Transport, Waste and the management process. Credits are awarded in each of these categories and a total score is calculated to assess the environmental performance of a building. A building will be rated as one of the following: Pass, Good, Very Good or Excellent.

Therefore, a BREEAM certified building has several benefits for clients, developers, owners, property agents and managers as the incorporation of green practices into a building will result in improved performance through a more efficient use of resources, a healthier environment for all occupants and a reduction in running costs. Lastly it will illustrate good environmental objectives in a highly competitive market place.

Green Star (Australia)


The Green Building Council of Australia (GBCA) launched Green Star in 2003- an environmental rating system used to assess green buildings. The development of Green Star was significantly influenced by the BREEAM rating system. Therefore, these systems are very similar; however, Green Star has been adapted to consider the local environment, the climate and the practice of the Australian construction industry.

This rating system evaluates the effect of a building on the environment and the innovation used in the sustainable practices whilst taking into account the reduction in costs, increased productivity and the creation of a healthier environment for occupants. Furthermore, Green Star was developed in order to create a benchmark for green building in the property industry. In addition, it was created to recognise superior green buildings and to establish a standard form of assessment for green buildings. Lastly, Green Star aimed to create awareness for the benefits of green building.

Green Star has nine categories that are included in the assessment of the environmental impact of the building. These categories are Management, Materials, Innovation, Indoor Environment Quality, Land Use and Ecology, Water, Energy, Transport and Emissions. Each of these categories is divided into credits. The building is awarded points in each credit according to overall environmental performance of the building .  The credits in each category are then calculated to establish an overall percentage score and the Green Star environmental weighting factors are applied. The environmental factors are distinctive to specific states in Australia.

Green Star has the following certified ratings: 4 Star Rating (45-59) indicates a Best Practice in environmentally sustainable design and/or construction, 5 Star Rating (60-74) indicates Australian Excellence in environmentally sustainable design and/or construction and 6 Star Rating (75-100) indicates World Leadership in environmentally sustainable design and/or construction. Although the achievement of a Green Star rated building is a formal process, this system can be used as a guide and benchmark in the incorporation of green practices.

CASBEE (Japan)


Comprehensive Assessment System for Building Environmental Efficiency is a relatively new system, which was developed in 2001 in Japan. CASBEE was developed with the following objectives: firstly, the system was developed to award superior buildings with high assessments. This therefore, would create an incentive for designers and owners to incorporate green practices into their buildings. In addition, the system would be simple and would be applicable to a several building types.

CASBEE includes a range of building types including: CASBEE for pre-design, CASBEE for existing buildings, CASBEE for new construction and CASBEE for renovation. Each of these assessment tools relates to the building lifecycle.

CASBEE, unlike the other rating systems, distinguishes the effect on the environment from the quality of the performance of the building. Therefore, this has resulted in CASBEE results reflecting the measure of eco-efficiency of a building or Building Environmental Efficiency (BEE). The BEE approach is unique to this rating system.  The BEE approach places the relevant categories into two groups. These two groups are environmental loading (impact on the surrounding environment) and environmental quality performance (indoor environmental quality). An assessment conducted in accordance to these groups will result in the determination of the BEE.

In addition, CASBEE utilizes several major categories in order to evaluate the buildings environmental rating. These categories include: Indoor environment, Outdoor environment on site, Quality of services, Resources and materials, Off-site environment, Energy, Building quality and performance. Once the buildings have been assessed one of the following ratings will be given to the building: C, B-, B+, A or S.  C is the lowest rating and S is the highest rating that can be achieved.

Green Star (South Africa)


Green Star was released in South Africa in 2008. This system was developed by the Green Building Council of South Africa (GBCSA) and is based on the Australian Green Star system; however, it has been changed to suite local conditions. Green Star provides a benchmark for green building in the property industry and recognizes and rewards superior green buildings.

The Building Council of South Africa (GBCSA) developed the Green Star SA Office, which was released in November 2008. This rating tool for offices evaluates the environmental features of new office buildings together with extensive refurbishments of existing office buildings. In addition, in May 2010, the GBCSA introduced an assessment tool for retail developments. Furthermore, a multi-unit residential rating tool is in the process of being developed and is expected to be released in 2011. The GBCSA develops tools according to the market demand.

Green Star South Africa uses the same nine categories as Green Star Australia. These categories are Management, Materials, Innovation, Indoor Environment Quality, Land Use and Ecology, Water, Energy, Transport and Emissions. In addition, Green Star South Africa also uses similar levels of certification to Green Star Australia.

The following Green Star SA certified ratings are available: Four Star Green Star SA Certified Rating recognises (‘Best Practice’- 45-59 points), Five Star Green Star SA Certified Rating recognises (‘South African Excellence’- 60-74 points), Six Star Green Star SA Certified Rating recognises (‘World Leadership’ – 75+ points).

Furthermore, Green Star SA makes a distinction between two different certifications, namely ‘Design’ and ‘As Built’. A ‘Design’ certification may be submitted for and awarded at the end of the design phase of a project and the documentation is specific only to what can be demonstrated at the design stage. The intention is that the green rated building can be marketed as a Green Star SA certified building, having demonstrated the green strategies to be included in the project. At the end of construction, a project may submit for and be awarded an ‘As Built’ certification, verifying the procurement and implementation of green building strategies. The following table illustrated the aims and objective of each of the nine categories of the Green Star SA rating tool.