Very nice article about building design concept. Here they have given lot of technical information about the same and also we came to know the process of building design in USA. There are four level in that process and in the final level they said about Green Building method , i.e, xD. green building is an outcome of a design philosophy which focuses on increasing the efficiency of resource use — energy, water, and materials — while reducing building impacts on human health and the environment during the building’s lifecycle, through better siting, design, construction, operation, maintenance, and removal.
http://www.sustainablebuildingsseries.com
http://www.gsmiweb.com