LEED Delivers on Predicted Energy Savings

With its dominant position defining green building in the North American market, the LEED Rating System is a popular target for critics with a wide range of axes to grind, some justified, others less so. One of the more valid concerns is that LEED’s promises of energy savings (and therefore carbon reductions) are just that—promises. With the exception of LEED for Existing Buildings, which looks at actual operations, LEED’s various rating systems assign energy points to buildings based on predictions made during design. How well those predictions hold up in reality has, until now, been subject to conjecture.

At Greenbuild 2007 in Chicago, the U.S. Green Building Council (USGBC) and the New Buildings Institute (NBI) presented a groundbreaking analysis of actual energy performance of buildings that had been certified, as of the end of 2006, under LEED for New Construction and Major Renovations (LEED-NC). The results have something for everyone. They justify the critics by revealing that, for any individual building, there is little correlation between predicted and actual energy use, especially among buildings designed to use very little energy. The difference between actual and predicted performance was not all bad news, however—many buildings are using

less energy than was planned. Average energy performance across all the buildings in the study, however, was remarkably close to predicted levels. This information suggests that LEED is valuable as a policy tool because it delivers savings across a market, but that the building industry has work to do before it can ensure the life-cycle cost benefits of individual buildings.