OTTAWA - According to a report from the National Research Council of Canada’s Institute for Research in Construction, on average Leadership in Energy and Environmental Design (LEED)-certified buildings used 18-39 percent less energy per floor area than their conventional counterparts. However, 28-35 percent of LEED buildings used more energy than their conventional counterparts.
In addition, the study 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, green buildings can contribute substantial energy savings, but further work needs to be done to define green building rating schemes to ensure more consistent success at the individual building level.
The study was a re-analysis of data supplied by the New Buildings Institute and the U.S. 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 U.S. commercial building stock. The researchers also examined energy use by LEED certification level, and by energy-related credits achieved in the certification process.
It was noted that these findings should be considered as preliminary, and the analyses should be repeated when longer data histories from a larger sample of green buildings are available.
For a copy of the complete report, go to http://irc.nrc-cnrc.gc.ca/pubs/fulltext/nrcc51142/nrcc51142.pdf.