World Green Building Week: How Good Are the Numbers?

This week is "World Green Building Week," in which green building councils all over the world will celebrate their certified green buildings and their mission of greening the built environment. But what exactly are we celebrating? Are green buildings in fact achieving their stated goal of being on the leading edge of response to cutting carbon emissions to combat global climate change? What are the "true facts" about green building performance?

Last week, a friend and sustainability expert based at the University of California/Irvine pointed me to a 2012 paper by Professor John Scofield, physics professor at Oberlin College in Ohio. Professor Scofield analyzed the ONLY serious study of energy reduction claims for US green buildings and found significant methodological errors. He even documented that his own campus's showpiece green building, claimed to be "net zero" in dozens of publications, had never hit that mark. His analysis was peer-reviewed and presented at a conference of energy experts. It has never been refuted by anyone in the green building world. In fact, the response to any critics of the carbon reduction benefits of LEED certified green buildings has been pretty much the same each time: ignore the specific claims and ramp up the PR machine. We can, should and MUST do better than this.

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I think it's worthwhile to quote directly from the abstract for Professor Scofield's paper (You can find it here:

Comparing these we find that LEED median-energy buildings, on average, use 10% less site energy but no less source (or primary energy) than do comparable conventional buildings. LEED office buildings achieve 17% reduction in site energy, but again, no significant reduction in primary energy use relative to non-LEED office buildings. We further find that these results do not change significantly if LEED buildings are compared with newer vintage, non-LEED buildings. As greenhouse gas (GHG) emission correlates with primary energy, not site energy, we conclude that LEED certification is not yielding any significant reduction in GHG emission by commercial buildings.(Emphasis added)

With all the hoopla going on about "zero net energy" buildings, we need to recognize that what really matters are the source energy (carbon emissions) and carbon emissions embedded in building materials that are associated with ALL buildings, not just with a few "best of the best" examples. How will we know that green buildings are significantly better than "conventional" (i.e., non-certified) buildings, if we don't publish performance data for a representative sample of both and allow the superb researchers of the world to take a look. If they're not much better, then aren't we deceiving ourselves about the value of what we're doing? Don't YOU want to find out the benefits flowing from your work?

For the past 20 years, with many others, I have been a strong and outspoken supporter for green building and for building excellence that pushes the envelope of sustainable design and operations. But as advocates, we must be scrupulously and ruthlessly honest about what we find out.

Since 2010, I have been harping specifically on the issue of measuring and reporting the ABSOLUTE PERFORMANCE of buildings (not just relative improvement)  (see:, so that we can know the carbon reduction benefits from green building certification systems and from sustainable design and operations, certified or not.

In 2013, Ulf Meyer and I wrote The World's Greenest Buildings: Promise vs. Performance in Sustainable Design, a book that compiled the first-ever actual performance data of 55 green buildings from 18 countries. No one else has published a similar study since (note to self: it was a lot of - unpaid - work!), but such studies are vitally needed. The last serious study of the performance of LEED buildings, the one specifically critiqued by Professor Scofield, was published in 2008, figuratively an eternity in the evolution of green building design and sustainable building operations.

With the tens of thousands of professionals around the world invested in green buildings, we desperately need some "truth in advertising," and that means publishing real data on building energy performance over time, including honest comparisons of green buildings with high-performance "non-certified" buildings. Let's find out how much we can count on green building rating systems to cut carbon emissions. 

How about it? Which green building councils are willing to step up and take the "performance challenge"?

After all, only your parents love you unconditionally - but for everyone else you have to perform!