Since its inception, the LEED Green Building Rating System has been based on one overriding goal: To reduce negative environmental and human health impacts of the built environment by promoting innovation and transforming the marketplace. USGBC believes the built environment can be used as a positive force in our communities and for the planet as a whole. With each new version of LEED, the scope of the environmental and human health impacts addressed by the rating systems has grown as our understanding of these issues and their interrelationships has deepened.