Factors that the study identified as responsible for the increase included:

• The building averages 450,000 visitors per year, not the 300,000 anticipated by the model;

• Its two theaters operate for 7 hours daily, not the 2 hours anticipated by the model; and

• Office space is used 7 days a week, not 5.

According to a spokesperson quoted in the Observer article, the library did not track its energy consumption “due to the cost.” Rather, it was “a reflection of [the library's] faith in the LEED certification process that [it] did not go back and second-guess the efficiency of the equipment.” As the Observer notes, the building’s increased energy requirements are, in some sense, due to its own success. However, as ASHRAE Fellow and Distinguished Lecturer Larry Spielvogel, P.E. pointed out in a letter to the New York Times which we reproduced here at GRELJ last summer, “[b]uildings alone do not use energy. The occupants, operators, and systems do.” The factors driving ImaginOn’s performance gap are another example of why the type of predictive energy modeling on which LEED relies is 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.

I also think it is also useful here to emphasize again that, under LEED 2009, this type of performance gap would not be the basis for a LEED 2009 decertification proceeding. Rather, the decertification discussion which was so heated last summer related to LEED 2009 projects which fail to commit to sharing performance data or to satisfy any of the other new Minimum Program Requirements- not if projects simply use more energy than anticipated.

• ImaginOn’s Energy Use Grows With Popularity (Charlotte Observer)

Although the study concluded that these 19 green buildings were consuming (on average) 40 percent more energy than predicted, all of the buildings were consuming less than a building designed to Massachusetts baseline building codes. The disparity in predicted versus actual energy consumption is probably not surprising, but the study did identify a number of issues common across the buildings which resonate with many of the technical and operational provisions of documents like the Model Green Lease. I think it is therefore worthwhile to review the study both from a green leasing perspective, but also in terms of LEED, particularly because the Lowell study has not been referenced in many of the recent articles discussing the ongoing LEED performance gap.

Among other factors, the study identified the following as accounting for the disparity in predicted versus actual performance:

• The predictive energy models used during the design phase were created based on the incremental amounts of projected energy savings from each of the proposed systems and efficiency measures which, according to the energy modelers interviewed for the study, did not account for the building’s performance in its entirety once those systems were installed and operational;

• By nature, predictive energy modeling does not account for the behavior of building operators and occupants with respect to their use of plug loads, occupancy levels, and operating hours (but note the importance of green leasing practices in this context);

• Design and materials changes during the construction phase on account of budget constraints (which emphasizes the need for ongoing construction counsel); and

• Some of the buildings suffered from increased energy consumption during the initial months of occupancy due to incompletely installed or commissioned systems, which the study concluded stemmed from contractors who incorrectly set the systems initially, as well as occupants who did not understand how to use the systems.

In addition to suggesting that these specific design and construction factors may impact green building performance, I think it is also important to note that the authors identified a “frustration” in stakeholders over the observed energy performance gulf. The study suggests that the gap be bridged through “communicating uncertainties in design predictions” and “better training in the use of the technologies in the buildings;” the former is a marketing and construction contracts issue which we’ve frequently discussed in the context of LEED, while the latter can be addressed through the use of various types of green lease provisions.

Although the study itself is somewhat dated, I do think that it emphasizes two important points. First, LEED building performance has been a question mark for quite some time, and will likely remain a critical issue for the foreseeable future, particularly while industry stakeholders continue to grapple with addressing the foregoing building performance factors through risk management strategies, construction contracts, and green lease provisions. Second, it confirms the unpredictable nature of energy modeling and importance for project teams to manage their clients’ expectations when discussing the opportunities presented by green building and other sustainable construction practices.

• Barrientos, J., U. Bhattacharjee, T. Martinez, and J. Duffy, 2007, “Green Buildings in Massachusetts: Comparison between Actual and Predicted Energy Performance,” Proceedings Annual Meeting American Solar Energy Society

As you may know, among other provisions, the San Francisco green building ordinance requires commercial and residential projects greater than 25,000 square feet, or taller than 75 feet, to earn a LEED Certified rating from USGBC. The requirement for commercial projects increased this year to Silver and, in 2012, to Gold. Residential projects must earn a Silver rating beginning in 2010. Notwithstanding these phased requirements, in the Chronicle piece, the San Francisco Department of the Environment’s private sector green building coordinator Richard Chien states that “[w]e need to reconvene the task force that recommended the legislation and makes some revisions way before 2012. With the changes coming along [to LEED] we could be out of date and we need to address that.”

Interestingly, the San Francisco ordinance (No. 180-08 of September 4, 2008, codified at Chapter 13C of the local building code) states that “[w]herever specific LEED prerequisites or credits are cited, such references are to LEED-NC Version 2.2. More recent LEED . . . versions may be used, provided the credits and points achieved are as or more stringent than LEED-NC Version 2.2.” In other words, because the LEED 2009 MPRs are not referenced specifically, it’s not entirely clear whether they are included within the purview of the ordinance, particularly with respect to mid-sized commercial buildings which are only required to comply with certain LEED credits.

The introduction to the article is therefore inaccurate; San Francisco is not reconsidering whether to restructure its green building ordinance around something besides LEED based on perceived LEED building performance failures. Rather, it is evaluating if, as presently drafted, and based on the recent amendments to LEED in the form of LEED 2009, its ordinance will still (1) obligate covered projects to comply with the new MPRs and share performance data; and (2) whether the ordinance should be revised to expedite that requirement. This is precisely the type of scenario that has been suggested both here at GRELJ and elsewhere with respect to the potential consequences for state and local governments that incorporate LEED into legislation by reference. Notwithstanding its performance-related issues, LEED itself continues to be a moving target and policymakers must guide themselves accordingly when considering the merits of this type of legislative activity.

I also think the Chronicle article is noteworthy because it suggests- once again- an overarching perception that simply collecting an increased volume of building performance metrics will solve the LEED performance gap. For example, consider the following quote from architect Jennifer Devlin of San Francisco-based firm EHDD: “LEED has done an exceptional job of raising awareness. And the U.S Green Building Council recognizes that tracking energy use is vital to the sustainable building movement.” LEED has unquestionably raised public awareness about the environmental impact of the built environment and put building performance on the front page of major media outlets such as the New York Times and the Chronicle. But, as USGBC’s Building Performance Initiative and other efforts ramp up this fall, I think it is critical to keep in mind Larry Spielvogel’s thoughts from our last article here at GRELJ that the question of improving building performance is highly complex and clearly one that cannot be solved by simply compiling a longer spreadsheet.

• Green Building Standard Seen as Flawed (SFC)