In 2000, the U.S. Green Building Council (USGBC) introduced its Leadership in Energy and Environmental Design (LEED) green building rating system. LEED is arguably the most popular green rating system in the United States, and has been instrumental in the progression of sustainable thinking in the built environment. Owners are asking if LEED certified buildings are directly influencing primary energy utilization and GHG emissions, and if so, how much? Two reports attempt to answer this question based on empirical evidence.
New Buildings Institute’ report “Energy Performance of LEED for New Construction Buildings” analyzed measured energy performance for 121 LEED New Construction buildings. Measured performance results show that on average LEED buildings are saving energy. The bad news is that there is a wide scatter among the individual results that make up the average savings, with a significant number of buildings using more energy than average for comparable existing building stock. The take away from the NBI report is that performance energy results from LEED certified buildings vary greatly, and that better measured performance and feedback is required.
John Scofield, a professor of physics at Oberlin College, authored “No Evidence LEED Building Certification is saving Primary Energy”. Professor Scofield uses scientific data analysis of existing performances of LEED certified buildings. His report analyzes the public relations marketing versus performance data for existing LEED certified buildings. His conclusions are, as his title suggests, there is no direct evidence linking performance of buildings to LEED certification. Of particular interest is the collective momentum from all sides to understand the need for measuring performance of buildings.
- Disclose the building’s EUI. If it is an existing building, disclose the existing EUI. If it is a new building, disclose the as-designed or planned EUI. Then, disclose the post-construction EUI based on actual performance data.
- After this fundamental step, we can begin to debate and compare green rating systems.
Imagine in 10 years, looking back at this period and wondering how we classified any buildings as sustainable, without specifically addressing energy utilization and impacts on GHG emissions.