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Can USGBC Improve the Performance of LEED Buildings by Collecting More Data?

Mireya Navarro’s recent piece in the New York Times about the energy performance of LEED buildings does not really shed much new light on a topic that many of us have been paying close attention to for the past two years, particularly in the aftermath of the controversial New Buildings Institute study that claimed LEED buildings performed, on average, 25 percent better than the CBECS database. Nevertheless, Navarro’s piece seems timed to coincide with USGBC’s press release of August 25 that announced a new Building Performance Initiative which will complement the LEED Version 3.0 Minimum Program Requirements’ ongoing performance data reporting obligations in order for projects to maintain their LEED rating and avoid the unsavory potential consequences of decertification. Any commentary on this press release – at least in the blogosphere – appears to have been lost in the August doldrums, but I think it is worthwhile to consider an effort which could ultimately have major repercussions for the underpinnings of the LEED system itself. However, many building scientists will tell you that simply collecting more data does not necessarily translate into improved performance. Consider the following letter that was submitted to the New York Times by ASHRAE Fellow and Distinguished Lecturer Larry Spielvogel, P.E., in response to the USGBC press release announcing the Building Performance Initiative, which Mr. Spielvogel was kind enough to allow us to reprint here at GRELJ:

The USGBC August 25, 2009 press release about their Building Performance Initiative implies that a large-scale collection of energy data from LEED® buildings will improve energy performance. This suggests a response to escalating criticism about the actual energy use of LEED® certified buildings compared with all others. Why do few published stories about these buildings include metered energy and water use data? If these buildings can waste energy efficiently, perhaps one answer is not to include those measures that allow that to happen.

The reality is that neither predicted nor actual measured energy use determines whether a building is energy efficient. Nor does energy use alone determine whether a building meets or exceeds all required or desired criteria, or provide the accountability necessary to achieve those results.

I have been collecting and evaluating detailed metered and measured building energy performance data for 40 years. Collecting the data is one thing, even if done completely and correctly. However, evaluating the data and then making comparisons among buildings is something else. Buildings alone do not use energy. The occupants, operators, and systems do.

In an extreme case, look at apartment buildings where each apartment is identical, and the metered energy use per apartment can easily vary by 2 or 3 to one, or more. Individually metered floors in office buildings occupied by the same company or tenant also can vary by 2 or 3 to one.

The functions in a building can also have a major influence on building energy use. The presence of a laundry in a hotel or hospital can make a 25 to 50% difference in total building energy use per bed, room, or square foot compared with an identical building on the same street.

Buildings with intermittent occupancy present similar dilemmas. How does one estimate, predict, or compare the energy data for two identical churches on the same block built at the same time, when one is only occupied for a few hours each Sunday and on some holidays, and the other is occupied most days of the week?

Comparing metered energy use to modeled energy data is not a valid measurement of anything. If the modeling and estimating methods were sufficiently accurate, utility companies would not require the use of meters.

Some articles I wrote 25 years ago show apartment by apartment or office floor by office floor metered energy use data in the same building. For another good example, look at the range of energy data for any given building type shown in the statistically significant quadrennial CBECS reports, collected at a cost in eight figures.

That reminds me of an energy research project 35 years ago during the 1970’s energy crisis. The US Postal Service spent hundreds of thousand of dollars instrumenting and recording the detailed energy use in a large postal facility. The conclusion was that they could collect lots of data.

The answer in evaluating and comparing energy data is using professional judgment and experience. That involves knowing and understanding not only the energy use and particulars of the subject building, but also the energy use and particulars of comparable buildings in the area. Comparing the energy use of a suburban office building in Boston with suburban office buildings in Providence without knowing the particulars is not likely to be meaningful or conclusive. This is much like the commercial real estate appraisal profession.

I think that there are a few important things to consider here. First, in USGBC’s Building Performance Initiative press release, LEED Senior Vice President Scot Horst notes that “[p]lenty of people are content to simply point to these longstanding issues [relating to LEED building performance] without offering a constructive way to address them. We’re going to take them on and engage practitioners and thought leaders alike in establishing a national roadmap to optimize building performance.”

After last fall’s Greenbuild, I suggested over at gbNYC that, if USGBC was serious about improving the energy performance of LEED buildings, it needed to engage building scientists such as Henry Gifford, Joseph Lstiburek, and Mr. Spielvogel in a meaningful way- certainly through more of an effort than simply collecting more data. As Mr. Spielvogel notes in his letter above, “[b]uildings alone do not use energy. The occupants, operators, and systems do.” This, of course, is what makes the type of predictive energy modeling on which LEED relies so imprecise and why project teams need to remain careful about the types of representations they make to their clients about the performance-related results of potential LEED certification. As Pat Murphy noted in a recent comment here at GRELJ, “[t]here is a crying need for accurate, verifiable and reliable energy rating systems. If LEED doesn’t fill the bill, other options will come forward.” I agree with Mr. Murphy and, in conclusion, would suggest that this is precisely what should give policymakers pause as they consider incorporating LEED- as currently constituted- into state- or local-level green building legislation.

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7 Responses to Can USGBC Improve the Performance of LEED Buildings by Collecting More Data?

  1. Timothy P. Runde, MAI, LEED-AP September 15, 2009 at 5:14 am #

    I think USGBC is absolutely on the right track in requiring building energy performance reporting.

    As an appraiser with 20+ years’ esperience in valuing commercial and residential buildings (including analyzing operating statements), I understand the difficulty of comparing seemingly similar properterties that nonetheless have very different operating profiles – whether due to cocupancy, use, age, design, size, geography, orientation, etc. I agree with Mr. Spielvogel that profeesional judgement and experience is key to effective and accurate use of any type of operating data. But impeaching the data because of its potential limitations would be unwise. Collecting more data won’t in and of itself make buildings more efficient. But without the data, those of us with professional judgement and experience will have little to work with.

  2. Stephen Del Percio September 16, 2009 at 1:25 am #

    Thanks, Tim. Agreed, but I think the danger here is a lingering perception that more data is a proxy for improved performance, which as you point out it is not. What USGBC does with an increased volume of building metrics will be interesting to follow.

  3. Brian D. Anderson September 24, 2009 at 2:47 pm #

    Mr. Murphy comments on the “crying need for an accurate, verifiable and reliable energy rating systems.” Do we already have such a system with Energy Star (http://www.energystar.gov/index.cfm?fuseaction=labeled_buildings.locator)? I haven’t seen much analysis on your blog or elsewhere of the merits/shortcomings of Energy Star. But my energy consulting friends–who actually get paid to audit and make recommendations on building portfoilio energy performance–use it and related software on a daily basis. As I understand it, the Energy Star tool incorporates size, use, region and age in producing a simple percentile ranking. I would appreciate hearing from others regarding their experience with Energy Star.

  4. Stephen Del Percio September 25, 2009 at 12:31 pm #

    I’d also be interested in digging a bit deeper into the Energy Star program, Brian- you’re right, we haven’t heard much about it in the recent discussions about building performance. (I would note, though, that over at gbNYC we’ve written about Energy Star award winners here in New York City and the recent successes that many have had in landing tenants in a lousy commercial leasing climate. I would also point out that the RICS study, which we talked about here at GRELJ earlier in the year, found that “the LEED rating has no statistically significant effect upon commercial rents, but the Energy Star rating is associated with rents higher by 3.3 percent.”). Your comments also suggest one other thought- that LEED for New Construction has become, as some have called it, a proxy for performance in the eyes of the public. Perhaps the recent attention to LEED building performance failures will mark a shift in a different direction.

  5. Eric Johnson September 27, 2009 at 12:31 am #

    It seems that people who don’t like LEED are out to “get” LEED.

    The New Buildings Institute study was confirmed by performed by the National Research Council Canada–Institute for Research in Construction.

    The New Buildings Institute study was correct to flag the lab buildings energy usage. The Labs 21 benchmark tool has a database of 170 buildings and a quick use of the tool will show that the mean (average energy use in all climates is around 550 kBtu/ft2).

    The modeled and actual used energy delta in the LEED buildings in the NBI study was less than 8%, not bad for not including plug loads.

    I would recommend the following reading: Lessons Learned from Field Evaluation of Six High-Performance Buildings, Moving Toward Transparency and Disclosure in the Energy Performance of Green Buildings, Evaluating the Site Energy Performance of the First Generation of LEED-Certified Commercial Buildings for starters.

    Gifford was right about one thing, no LEED building should have all of the lights on at 3 am with no one but security in the building. But that isn’t the USGBC’s fault, it’s the owners!

  6. Eileen Duignan-Woods,PE July 4, 2013 at 8:20 pm #

    Leed has a long and tortured history.From the onset is was clear that engineers were not considered and that architects were destined to be “in control”.

    I know that there are people who are seeking to level the playing field. I have in my possession a copy of The LEED Training Workshop manual, Jand J, New Brunswisck N,J.
    July 20 2001.

    For anyone who believes that history tells a story, this is an important document.

    I’m not interested in selling this for money just as a donation to setting the record straight on LEED.

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