BuildingGreen.com: LEED Energy Efficiency (and a brief discourse on definitions)

Nadav Malin, editor of Environmental Building News provides a nice summary of Henry Gifford’s thought piece about better ways to improve energy efficiency. The comments are excellent and include well-explained digressions from both Henry’s article and USGBC positions.

From Malin:

1) First, the LEED buildings are compared to the CBECS data set of all existing buildings, regardless of year of construction. Gifford argues that they should have been compared only to new buildings. The 2006 CBECS summary shows that buildings built between 2000 and 2003 use, on average, about 10% less energy than the complete data set for all existing buildings.

NBI’s Mark Frankel disagrees, noting that some of the LEED buildings are actually renovations of older buildings… [and] CBECS generally groups its buildings by decade, and those three years don’t represent enough of a trend to rely on.

2) Gifford’s second adjustment is to use the mean of the LEED data set instead of the median used by NBI. (The LEED mean was not published, but NBI provided it to Gifford upon his request.)

Based on repeated reads, I had many of the same problems with the Leonardo Academy’s “Economics of LEED-EB” paper. I found the data set too small and diverse to make any useful conclusions. I also felt the casual relationships unproven at best. As an example, LEED-EB reductions of security costs was suggested but so far beyond tenuous it was never described.

Returning to the Henry Gifford paper, I am also reminded about a recent posting at Green Building Law Update “Green Building Attorneys Warn of Carnage.” That posting highlights several recent discussions in legal circles about the enforceability and design of contracts that address specific performance standards. Reading through the comments at BuildingGreen, however, I kept running across questions that gave pause:

“When “building scientists” look at buildings from afar, we are virtually ignorant of what goes on inside them. We tend to treat them literally as shells, connected to power sources, that operate, more or less independently from the “activity” that they house.

We then are prone to missing the fact that energy-use “variance” might be the result of the very essence of the “activity” going on inside!”

So even if everyone agrees on a ‘sustainability’ program, if the design is faithfully built, if the MEP is commissioned and maintained, changing the user mix might prevent the realization of the “agreed upon” savings.

BuildingGreen.com LIVE: Lies, Damn Lies, and… (Another Look at LEED Energy Efficiency) by Nadav Malin on 09/02/2008: “”