BREEAM is the world's foremost environmental assessment method and rating system for buildings, with 425,000 buildings with certified BREEAM assessment ratings and two million registered for assessment since it was first launched in 1990. BREEAM sets the standard for best practice in sustainable building design, construction and operation and has be-come one of the most comprehensive and widely recognised measures of a building's environmental perfor-mance. It encourages designers, clients and others to think about low carbon and low impact design, minimising the energy demands created by a building before considering energy efficiency and low carbon technologies.