Comparative study of green building rating systems : in terms of water efficiency and conservation

The construction industry puts a great effort on achieving sustainable development. This is because in the construction industry a lot of natural resources are being consumed. Water is one of the most important natural resources for the development of all economic activities taking place to care for the environment and quality of life in the society. Therefore, availability and management of water resources is essential for a long term sustainability of any country. At present, many environmental assessment tools or green building rating systems developed and accepted by many countries. Simply, green building rating systems provide best standards and assist to fulfil green building practices. Each rating system addressed key sustainable parameters: energy, water, site, indoor environmental quality and materials in order to build sustainable environment. Since freshwater scarcity has become a global issue, this paper aims to investigate how and in what strategies water efficiency and conservation is discussed in the existing green building rating systems. Primarily, literature review and documentary review were used as the main research method. The eleven green building rating systems which are designed for new construction were considered and were analysed to compare in terms of the key requirements/strategies and credits awarded for water efficiency and conservation in the rating systems. It was found that in terms of water, intention of each rating system is to reduce potable water consumption compared to the benchmark buildings. It further address in many directions to conserve and monitor water throughout the project life cycle. However, few rating systems have only addressed water conservation and water pollution during the construction phase. Furthermore, the paper enables to analyse the priority given for the water efficiency compared to other sustainable parameters