Green Building Rating Systems:Comparative Review of IGBC Green Homes and CASBEE for Detached Homes

Continuous rise in population levels in the developing world and servicing this need for housing on a large scale should be carried out in a sustainable manner. This has led to green building rating agencies to publish separate rating systems, particularly for the residential and housing sector. This review study aims at comparing two such green building rating systems of the housing sector. CASBEE for homes (Detached Houses) is chosen, as Japan being a developed island nation although having its own problems with regards to lack of housing space for its growing population and constant tectonic activities has come up with unique solutions to these problems that can be adopted in countries with similar issues. IGBC Green Homes being a vastly adopted rating system of the housing sector is compared to CASBEE to have an idea about the shortcomings of each rating system. The green building industry in both countries and the history of sustainable architecture is compared to give a look into the reasons behind adopting green building rating systems. The supporting regulatory framework of both countries along with the method of implementation of the systems is compared. Finally the strengths, weaknesses, opportunities and threats of each rating system are reviewed. This study provides some insight into the gaps present in both systems, and can be used while developing an add-on to the rating systems to ensure that all aspects of sustainability are covered while planning for the new development.