A critical comparison of green building rating systems
Various green rating systems are established globally to evaluate the sustainability of construction projects. Their categories and criteria have been under constant updates to follow the sustainable trend of building development. This paper aims to develop a systematic review of the development of green rating systems. The specific objectives are: 1) discover how interest and research in green rating systems have developed; 2) identify the similarity, difference, strength and weakness of green rating systems; 3) examine whether they fully assess the projects in all aspects of sustainability. Specifically, LEED (Leadership in Energy and Environmental Design), BREEAM (Building Research Establishment Assessment Method), CASBEE (Comprehensive Assessment System for Building Environmental Efficiency) and Green Star NZ were analysed in this paper. The results indicate that BREEAM, LEED, and CASBEE have been utilized since late the 2000s while Green Star NZ is still in its earlier stages. 70% of the research papers focusing on BREEAM, LEED, CASBEE are developed geographically in the USA, Canada, the UK, China, and Australia. Although these four rating systems were initiated in different contexts with different standards, Indoor Environment Quality, Energy, and Material are core common categories for all. Environmental concerns are the main focus in New Construction manuals while Society is emphasized in Neighbourhood Development manuals. Currently, BREEAM has been the only tool which could assess all four sustainable factors. Further in-depth research is anticipated to focus more on economic and institutional factors to improve the capability of green rating systems for sustainability assessment purposes.
Synthesis method: Qualitative for content. Quantitative for documenting bredth of research.
Conclusions: The results indicate that green rating systems have become the focus point of various researchers recently. Since 1998, 408 papers mentioned BREEAM, LEED, or CASBEE in E&B, B&E, A&C, BR&I, SBT&UD, CP, EIAR, R&SER while 202 of these papers focused on these ratings with a more in-depth approach. During the research period of 1998 - 2016, the number of green rating related papers rises sharply from only 2 to 36 on an annual basis. BREEAM is the first released green rating system in the world which certified approximately 560,000 buildings, but LEED is seen as the most flexible tool used in 160 countries and territories. In addition, there are a significantly higher number of papers discussing LEED compared to BREEAM concerning the eight main journal sources for this research since 1998. While the CASBEE and Green Star NZ related research papers are still limited. Green or sustainable building assessment is a global concern in both developed and developing countries. USA, Canada, the UK, China, and Australia have contributed up to approximately 70% of the total papers while Turkey, India, Brazil, and Malaysia are prominently considering green rating systems in their research schemes. The similarity, difference, strength, and weakness of green rating systems were also identified based on the research manuals. The total categories, sub-categories, points, and mandatory credits tend to increase and more comprehensive in order to completely assess the sustainability of a project. LEED is the particular scheme in which the total points and mandatory credits were double in the version 4 since the version 2 besides the addition of two more categories. BREEAM is considered as the strongest rating system in which Environment and Society are carefully assessed along with the consideration in Economy and Institution. The weakest system could be Green Star NZ when it could only focus on one pillar of the sustainability, Environment. While Society is critically evaluated by LEED; and CASBEE is a well-balanced tool in Environment, Society, and Economy assessment. However, no rating scheme could assess a project in all aspects of sustainability. This paper could be valuable for both green practitioners and researchers to have an overall understanding of BREEAM, LEED, CASBEE and Green Star NZ. Categories, points, and mandatory credits were discussed in details to pinpoint the current status/ tendency of the green building rating systems. In addition, strengths and weaknesses of each rating system were also analysed. Besides, the difference between New Construction and Neighbourhood Development/Communities/Urban Development were also examined to identify which sustainable pillars could be assessed by these tools. It is recommended to include Economic and Institutional factors as supplementary assessment criteria and manuals for green building rating systems for a more comprehensive and through review of the project. Further research is needed to validate the impacts of adding Economic and Institutional factors to current green building certification systems. To provide a better background knowledge of green rating systems, Interior Design, Building Operation and other manuals should be examined, but this research was only considered two main manuals, New Construction and Neighbourhood Development manuals. In addition, only recently CASBEE's manuals were analysed because the previous ones are not in English. Furthermore, the examination in the four selected rating schemes may not reflect the overall trend of hundreds of schemes worldwide. These could be the limitations of this research.
Screening criteria: 202 papers. Abstracts were read to filter out the irrelevant papers. Unless the papers mainly focused on the green rating systems, they will be excluded. The aim of this first step is to a) observe the development of green rating systems, b) find out how they are popular in the research, c) discover which rating is more globally recognized, d) locate the countries concerning about green building. manuals of BREEAM, LEED, CASBEE, and Green Star NZ were examined to determine their developments, similarities, and differences along with their strengths and weaknesses to determine their support to sustainability. New Construction manuals and Neighbourhood Development manuals were investigated in this paper. New Construction manuals represent for a new individual building assessment guidance.
Search source: Scopus and Web of Science
Search keywords: “LEED”, “BREEAM”, CASBEE00, “Green Star NZ”, “Green Building”, and “Sustainable Building”
Funding source: This research has been supported with Vice Chancellor Doctoral Scholarship by Auckland University of Technology, New Zealand.