About 28% to 35% of LEED-certified buildings use more energy than conventional buildings, states a report from the National Research Council of Canada’s Institute for Research in Construction. This is against 18% to 39% using less energy per floor area.
The study also found that the measured energy performance of LEED buildings had little correlation with the certification level of the building, or the number of energy credits achieved by the building at design time.
Therefore the report concluded that, while ‘green’ buildings can contribute substantial energy savings, ‘green’ rating consistency at the individual building level needs to be defined.
The study essentially re-analysed 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.
This data was compared to the energy use of the general US commercial building stock. The researchers also examined energy use by LEED certification level, and by energy-related credits that are achieved in the certification process.