â€œItâ€™s not how efficient the building is but how much energy it really uses that matters.â€ Thatâ€™s the gist of many comments in a thread on BuildingGreenâ€™s blog (and, simultaneously, on several email discussion groups) about how to measure the actual energy performance of LEED buildings.
â€œItâ€™s not how efficient the building is but how much energy it really uses that matters.â€ Thatâ€™s the gist of many comments in a thread on BuildingGreenâ€™s blog (and, simultaneously, on several email discussion groups) about how to measure the actual energy performance of LEED buildings (see www.BuildingGreen.com/go/energy_data). Energy consumption surveys from the U.S. Department of Energy (DOE) confirm that, despite more efficient building systems, average energy use per square foot in U.S. buildings has held steady since 1920. As building envelopes and mechanical systems get more efficient, we demand more of them, and we keep finding more ways to use energy in our offices and homes.
All LEED rating systems except for LEED for Existing Buildings: Operations and Maintenance (LEED-EB: O&M) award plaques based on predicted performance as opposed to actual reductions in energy and water use and other indices. The U.S. Green Building Council (USGBC) is trying to address this gap by encouraging new LEED buildings to recertify under LEED-EB: O&M once theyâ€™ve been operating for at least a year. Short of deciding to rip plaques off the walls of underperforming buildings, however, USGBC has no way to enforce such recertification. To date, it has not even been able to mandate energy-use reporting so we could know how LEED-certified buildings are really performing.
Fortunately, some government agencies are stepping up to address this need, at least when it comes to energy use. Starting in 2010, Washington, D.C., will make the actual energy bills of large commercial buildings a matter of public record; smaller buildings (down to 50,000 ft2, or 5,000 m2) will be added in subsequent years. California, through Assembly Bill 1103, is also phasing in a mandatory reporting requirement, beginning, like Washington, with government buildings before extending to the private sector. In California, however, the driver is a push to benchmark performance of all buildings as a group; an individual buildingâ€™s energy usage will be revealed only when it is sold, leased, or refinanced. In this respect, Californiaâ€™s requirements are similar to those of the European Union (see EBN Vol. 17, No. 10).
If other jurisdictions follow California and Washington, LEED could soon be lagging behind codes by not requiring actual performance numbers on its certified buildings. To continue leading, USGBC needs to reserve the label â€œLEED certifiedâ€ for buildings that have their actual performance documented through an operations and maintenance-based rating system such as LEED-EB: O&M. Those buildings would have to be recertified regularly and could only claim that label as long as they keep up that performance. Buildings designed and built to meet the requirements of the LEED rating systems could be called â€œBuilt to LEED.â€ The market has shown that it can deliver buildings that meet LEEDâ€™s guidelinesâ€”now it needs to be pushed to make sure those buildings actually deliver the promised performance.
â€“ Nadav Malin