Do LEED-certified buildings save energy? yes, but..

Source: Institute for Research in Construction
"An analysis was carried out of data supplied by the New Buildings Institute and the US Green Buildings Council on measured energy use data from 100 LEED certified commercial and institutional buildings. These data were compared to the energy use of the general US commercial building stock. The authors also examined energy use by LEED certification level, and by energy-related credits achieved in the certification process. On average, LEED buildings used 18-39% less energy per floor area than their conventional counterparts. However, 28-35% of LEED buildings used more energy than their conventional counterparts."