San Francisco has announced the adoption of a Green Building Ordinance, which requires that all new projects, including city-owned facilities and leaseholds, achieve a Leadership in Energy and Environmental Design (LEED) Silver certification from the U.S. Green Building Council (USGBC).
The LEED Green Building Rating System, developed by the USGBC, is the only nationally recognized green building rating system. LEED evaluates the performance of buildings from a "whole building" perspective, over the course of a building's lifecycle, which provides a definitive standard for what constitutes a green building.