It is a UK green building certification system, launched in 1990 by the Building Research Establishment (BRE), similar to LEED. Both systems confirm the level of the sustainability performance of an asset.  Confirming the level at which the asset was designed and built using strategies aimed at improving performance across all the metrics that matter most: energy savings, water efficiency, CO2 emissions reduction, improved indoor environmental quality, availability of resources and sensitivity to their impacts.