Green Building not Performing? USGBC facing criticism...

Are green building requirements set by the US Green Building Council's LEED rating systems not performing to the energy efficiency projections as advertised? A couple of recent reports are saying not. Released by NAIOP, the Commercial Real Estate Development Association, the first report claims 30-50% energy savings over the ASHRAE 90.1-2004 Standard is virtually impossible to achieve within the ten-year payback cited in the study.

As has been touted elsewhere in blogs and articles, the study has a few holes in it. Most glaring is the application of similar buildings systems in varying climates. As the CoStar group puts it in their review of the study, "You don’t build the same building in Florida that you do in Chicago, and then plop it down all over the United States." Buildings and their systems at all levels should reflect climatic and site conditions, making it very difficult to assume a single building would perform similarly in different regions of the country.

Another study by Henry Gifford, and potentially more damning to the USGBC organization, offers a critical look at a report commissioned by the USGBC to analyze the actual performance of LEED Certified projects and energy efficiency claims of 25-30%. Some interesting info that will be interesting to watch play out, were the statements mentioned in Gifford's article pointing to the USGBC skewing information in the report to be misleading. A quote by Brendan Owen of USGBC definitely raises some suspicion:

I was really kind of cringing about what kind of data we would get. And, when Mark and I started talking about what this survey, and what this study was going to be, he asked some pretty pointed questions about what were we going to do with it, and in the back of my head it was, you know, if it’s bad, we’re certainly not going to tell anybody. And, and we’re going to fix the problem and that will be good. But I knew he wouldn’t let that happen, so in the front of my head was, if it’s bad I’m going to let Cathy [Cathy Turner, the senior analyst15 for the New Buildings Institute] publish just her graphs, with no explanation, and it’ll be so statistically impenetrable to anybody who could actually articulate what was going on, that it wouldn’t matter, because they, you know, could only talk to somebody else who could understand them, and there’s not many of those out there. So, the fact of, the delightful fact of the results of the study being what I would consider to be overwhelmingly positive considering how bad I thought it was going to come out, are pretty remarkable.

In regards to statistics in the report, Gifford points out ways in which the information presented is flawed and doesn't tell the entire story, from a relatively small sample pool, to comparing buildings built post 2000 (LEED) with those from much earlier time periods (as far back as 1920. I'm not an architect or engineer, but can tell you I doubt my 1928 Craftsman was built to the same efficiency standards as those of today, though with a little work I could probably be more efficient as older homes had to respond to climate without technology. Hopefully at some point I'll be able to insulate the walls, something common in modern construction. These studies are presumably reviewing commercial structures, so I digress.

When comparing the median value of the LEED buildings to the average of the non-LEED, the USGBC study found that the LEED structures use 69,000 BTUs per squar per year vs 91,000 BTUs for the non-LEED buildings (a 24% reduction). This reduces to a 15% reduction when comparing buildings of like age. However, when comparing mean to mean values, the actual usage for the LEED structures shoots up to 105,000 BTUs (a 29% increase).

Mr. Gifford as provides some great commentary on the current approach of projects going after the most visual aspects of green building vs. going the simpler route (and sometimes more effective). He also recommends that buildings be rated on actual performance and that certification could be revoked if a building didn't operate as efficiently year to year. Many other great tidbits including solar panels facing North and light sensors not turning off the lights.

If anyone has seen a rebuttal from USGBC, please let us know. I'm interesting in hearing what they have to say or if this may bring about change in the performance of LEED and certified buildings. Just did a quick search trying to find any info and saw that Mr. Gifford was attending a forum discussion of NESEA last night (3/10/2009) with Brendan Owens of USGBC and a video on youtube of a presentation by Gifford on his findings (haven't watched it yet, but thought it would be of interest). Any info on the forum, pass it along and I'll update this post.