LEED efficiency has increased over time
The U.S. Green Building Council in association with Ember Strategies recently studied 10 years of LEED (Leadership in Energy and Environmental Design) data to understand how energy efficiency has evolved.
A building’s potential LEED certification is determined by how much more efficient the design is than what would be required by the most stringent energy code. The difference between the building’s efficiency and the code requirements determines how many LEED points are awarded for energy efficiency. Green Biz reports that energy codes are re-written about every three years, creating a moving baseline, which makes it difficult, but not impossible, to track industry improvements over time.
The results of the study indicate that while the number of LEED certified buildings has increased through the years, the relative efficiency achievement has remained constant. Since 2006, the average design efficiency has consistently stayed around 27 percent, according to Green Biz.
However, since the benchmark has moved, this figure is deceiving. Green Biz reports “We know that average design efficiency of LEED v2009 buildings (about 29 percent better than the 2007 code) is much better than average design efficiency of LEED v2.2 (about 27 percent better than 2004 code), which is better than the average design efficiency of LEED v2.1 (about 37 percent better than 1999 code, for the buildings that earned the credit).”
According to The Department of Energy, each new code baseline marks a significant jump in efficiency over the old. So although the level of efficiency in LEED certified buildings has remained “constant,” today’s LEED structures are far more efficient than they were years ago.
Click here to download the full .PDF of the 10-year study.