On August 3, the New York–based architecture writer John Hill posted a photo of the entrance to Seven Bryant Park on Twitter. In the image, a LEED Gold plaque and a C grade (60 on a 0 to 100 scale) from the city’s Building Energy Efficiency Ratings program are displayed side by side. Critics of the LEED program, and of the green-building certification movement generally, seemed to have their suspicions confirmed. Surely, the discrepancy between the building’s LEED Gold status and its energy grade implies that the standards applied by the U.S. Green Building Council (USGBC) aren’t rigorous enough for Silver, Gold, or Platinum certifications to be meaningful.
Such an image, if interpreted out of context, can play into assorted rehearsed criticisms, whether it’s reducing the LEED system to a marketing tool or calling the entire energy measurement process into question. But it’s also true that challengers will be needed if the green-building rating complex is ever going to evolve. Is the city’s budding ratings program such a challenger?
New York prefers strong BEER
The Building Energy Efficiency Ratings system was introduced in 2019 as part of Local Law 95 (amending Local Law 33) and is formatted to resemble familiar restaurant-sanitation letter grades. (Regrettably, “BEER” is not in general use; most people call it the Energy Grading Law.) It is part of a suite of local laws (LL) under the Greener, Greater Buildings Plan encouraging energy performance and public disclosure. In the first year of letter grades, according to estimates prepared by Steven Winter Associates using public data, 38 percent of the city’s buildings with data available scored a D (an Energy Star score below 55), with another 20 percent exempted or uncounted. Grades A (85 or higher), B (70 to 85), and C (55 to 70) accounted for 14 percent each. Direct grade distributions using the city’s total of 24,071 “borough, block, and lot” identifiers, including sites submitting no data, differ slightly: 13 percent A, 13 percent B, 13 percent C, 36 percent D, 9 percent F for no data, and 16 percent N, covering cases where benchmarking occurred but Energy Star Portfolio Manager could not provide a score, sometimes because the EPA found too few similar buildings for comparison.
Because Portfolio Manager considers a building’s energy use, size, occupancy, program, and climatic context, comparing it with similar buildings nationwide, an Energy Star grade of 50 represents the national median, explained New York City Department of Buildings (DOB) press secretary Andrew Rudansky. But New York’s letter-grade system, he noted, was designed to be especially stringent. “Any Energy Star score from 0 to 54 will get a D. Meaning even if your building is ‘average’ when it comes to energy efficiency, you will still get a D.”
Some of the differences between the city grading system and the USGBC’s are obvious. A LEED rating, at least in the Building Design + Construction (BD+C) or Interior Design + Construction categories, is a one-time snapshot incorporating energy modeling and predictions, not an assessment of ongoing operations. It reflects the LEED version and regulations in effect at the time of the rating. It is also voluntary. The Energy Grade, meanwhile, “is based on actual operations,” said Gina Bocra, chief sustainability officer for the DOB, “so that takes into account the day-to-day operations and energy consumption of a building all year long.” It is a legal mandate, revised annually to encourage ongoing upgrades. “USGBC instituted a policy a few years ago that owners have to report their annual energy efficiency,” Bocra continued, but “they’re not going to come make them take their plaque down.”
Sometimes the systems harmonize, and sometimes they don’t. The city’s top-rated LEED Platinum building, One Citi NY (aka 388 Greenwich Street) scores an A. The second, 450 Park Avenue, gets a B. For some high-profile buildings, failing to disclose certain information to the DOB means a black eye: 35 Hudson Yards (500 West 33rd Street), rated LEED Gold, gets an F. Its Platinum neighbor 10 Hudson Yards (501 West 30th Street) gets a C. The tetrahedral “courtscraper” VIA 57 West (625 West 57th Street), the winner of multiple 2016 and 2017 skyscraper-of-the-year awards, may have been built to LEED Gold standards, but it scores a D.
Quantitatively or qualitatively green
Wisecracks about greenwashing, however, may be premature, perhaps even reductionist. LEED also assesses a broad range of environmentally relevant variables along with energy use. Melissa Baker, USGBC’s senior vice president for technical core, cites the mitigation of a building’s climate impact as the system’s primary goal. She cited the program’s “energy and atmosphere” category, which accounts for the highest proportion of points (roughly a third in LEED 4.1 BD+C). Yet a building can accrue points for other priorities—material choices, lighting, indoor air quality, location and orientation, vegetation and shade, innovative technologies, and encouragement of low-impact transportation (including bicycle racks)—making it possible to earn a plaque without excelling in energy metrics. Energy performance, the USGBC seems to be saying, is the primary but not the only way to be green.
Of course, gaps between modeling-based predictions and real-life performance have long been apparent to sustainability specialists. “When you look at these two things that seem to be unharmonious, they’re actually pointing to what we refer to as the performance gap,” said Billie Faircloth, partner at KieranTimberlake. “That ranges from the very modeling practices that we use while we’re predicting energy use all the way to our ability to predict how people actually inhabit and use space. It’s why I really like to see these two things as being incredibly important and complementary, rather than in contrast to each other, and actually indicative of the work that we need to do across the entire life cycle of a building.” She views commissioning, measurement, and performance verification as components of a process that does not end when a building attains LEED certification. “Maybe you could consider the LEED plaque like a trophy, and the [Building Energy Efficiency Ratings] label is more like a report card. You’ve won a trophy, but you’ve got to keep working.”
Despite LEED’s role in bringing a building’s environmental performance into the public consciousness, “LEED bashing has become fairly popular,” said Lance Hosey, FAIA, chief impact officer at HMC Architects in San Diego. “I’m always careful to look at both sides of that coin. One is, there’s a chance we might not have had this conversation if it weren’t for the USGBC and LEED.”
Backlash positions have different motives and levels of merit. Some critiques have been traced to astroturfing organizations such as the so-called Environmental Policy Alliance, the work of a notorious lobbyist, Richard Berman, and linked with nested networks of front groups defending the tobacco industry, polluters, opponents of food-safety policies, and similar interests. Other analyses are more open and scientific, such as physicist John Scofield’s contention, using energy data released under LL84, that many of New York’s Gold LEED buildings actually underperform non-LEED buildings. The New Building Institute, commissioned by the USGBC and the EPA to analyze a sample of 121 LEED-new construction buildings in 2008 using quadrennial Commercial Buildings Energy Consumption Survey (CBECS) data for comparison, found encouraging correlations between LEED status and energy use intensity (EUI). But critics such as Scofield remain unpersuaded and repeatedly second-guess the USGBC’s methods and findings.
“There are studies that show that it’s all over the map,” Hosey said, “that there are LEED Platinum buildings that perform much better than anticipated, and there are LEED Platinum buildings that perform much worse than anticipated to the point where some of them actually don’t even meet the energy code. Now, that’s not a fault of LEED; it’s a fault of the accuracy of the programs we use to model with energy ahead of time, and what we’ve learned is that when you actually measure it in reality, there are all kinds of subtleties and complications.” Occupants’ energy use can be unpredictable, particularly in buildings with trading floors, where plug loads are extreme. The popularity of green buildings may even be a factor in inflating their metrics, Baker suggests. “We found anecdotally that people really like green buildings, so often they get used more,” attracting tours, meetings, and rentals that boost energy use.
Citing a Harvard study of indoor air quality and cognitive function, Hosey notes that green buildings defined more holistically—i.e., emphasizing a range of features that constitute indoor environmental quality (daylight, thermal comfort, acoustics, fresh air, connection to the outdoors)—are healthier and more popular, independent of energy performance. In contrast, with insufficient air changes, mold buildup, and excessive particulates, “you could have the most energy-efficient building in the world, [yet] it’s also bad for people to occupy.” In other words, the progress of green design and construction reflects a dialectic between performance and habitability rather than a linear pursuit of a single measurable aim.
Flak magnets and catalysts for progress
One high-profile Manhattan building crops up again and again in discussions of prediction/performance discrepancies: the Bank of America Tower at One Bryant Park, the first skyscraper to be rated Platinum by LEED, now graded C by the DOB. Paula Zimin, director of sustainable building services at Steven Winter Associates and a member of AIANY’s Committee on the Environment, raised multiple questions about how the DOB’s process could lead to such a discrepancy: whether the building reported energy use and square footage accurately; whether the EPA’s reliance on source EUI rather than site EUI skews the calculations against buildings that use higher ratios of electricity; whether CBECS data based on average national building sizes misrepresent important aspects of New York buildings’ scale and proportions. “Why are we being compared to buildings that really aren’t anything like us?” she asks.
One Bryant Park is unique both in its well-publicized green features and in its high-plug-load data center. “Let’s say that the threshold for cooling performance wasn’t super high,” Zimin speculated. “And I would imagine One Bryant Park was using the best of the best in terms of cooling, knowing that they had this huge data center that they had to cool, so it’s very possible that they could claim—for LEED purposes—that much savings. It’s all about where your baseline is.” Metrics in constant refinement, she added, inevitably collide with “what the state of the art was when this building was developed.”
Apoorv Goyal, associate in the design analytics group at Elementa Consulting and another member of AIANY’s Committee on the Environment, also cites One Bryant Park and its neighbor, the LEED Gold–certified Bank of China tower at Seven Bryant Park, as salient cases of non-correlation between EUI and LEED status. “It’s really an apples-to-oranges comparison,” he said, adding that scrutiny should really be placed on greenhouse-gas (GHG) emissions rather than electrification. “The building grades and LEED status, both of them, are not talking about GHG emissions at all,” he continued. Comparisons with CBECS data on what buildings of this size use yield an Energy Star rating that disregards a key component of the building: its data center. Any energy model includes assumptions about equipment power densities, he said.
For this reason, Goyal favors “reassessing the LEED model after two years’ or three years’ time and basically calibrating your equipment power densities, calibrating your occupancy and user schedules, and reassessing what you report.” Moreover, he underlines the necessity of moving to an evaluation model that uses carbon metrics, which LEED 4.1 already does. “I think both these systems need to actually go into tons of carbon on-site saved, because that’s a direct A-to-A, apples-to-apples comparison,” he said.
In part through work on their own headquarters in Philadelphia (converted in 2015, coincidentally, from a former beer-bottling plant), Faircloth and her colleagues at KieranTimberlake have developed a set of digital tools to assist with design and operations. The wireless sensor network Pointelist collects highly granular data on temperature and relative humidity measurements that helped the architects identify areas of potential comfort or discomfort from season to season. The postoccupancy survey tool Roast provides data on thermal comfort during seasons when the building runs in a mixed mode. And the whole-building life-cycle assessment application Tally helps monitor “the total carbon picture,” both operational and embodied carbon, including emissions associated with building materials and interior finishes. Tally was transferred last May from KieranTimberlake to Building Transparency as part of the Embodied Carbon in Construction Calculator platform of tools, adding to the resources that architects can use to predict the outcomes of design decisions with more precise information than any single rating can provide.
“The plaque doesn’t necessarily lead to action,” Faircloth said by way of summing up. “It points to action [that] has already happened. The letter grade points to the current state, but also action that could happen in the future to increase the performance of that building.”
Bill Millard is a regular contributor to AN.