Update: LEED building study
Last June I wrote about a study by the New Building Institute claiming LEED certified buildings were 25-30% more energy efficient than similar non-LEED buildings. After the study was released, a number of criticisms of it were leveled, ranging from the choice of the comparison set of buildings to selection bias caused by the voluntary LEED sample used to the use of medians instead of means. Henry Gifford wrote a paper challenging many of NBI study’s claims and methods along with the rating system altogether. Gifford’s paper maintains that LEED buildings actually use more energy than their non-certified counterparts. It is available here and is worth checking out if you are interested in the issue. The NBI has a response to many of the criticisms on its site here.