Some call it “Darth Vader’s Summer Palace.”

Stretching across approximately 150,000 square feet of land at 55 Lock St., the dark, looming structure that houses the Yale University Health Center may look formidable to some. But the interior floods with natural light — just one aspect of the structure’s sustainable design initiatives.

Thirty-four percent of the Yale Health Center’s installed material came from recycled materials such as locally manufactured steel, concrete and wood. In an effort to promote public transportation, the location is also easily accessible — it can be reached on foot, bike or bus.

The building is the most recent Yale facility to receive Leadership in Energy and Environmental Design certification, guidelines set by the nonprofit U.S. Green Building Council for evaluating a building’s sustainable practices. When it opened in August 2010, it was the 12th Yale building to be certified since 2005. Seven Yale labs, which are part of larger buildings, have also received LEED certification.

As one of the highest consumers of Yale’s energy resources, laboratories offer a high potential for energy savings to help meet University-wide sustainability goals, said Virginia Chapman, director of sustainability initiatives for the Yale Office of Facilities. But the LEED ranking system pertains to more than just science-related buildings: it also applies to educational, retail and housing facilities. The new residential colleges, for example, will be constructed to meet LEED Gold certification standards, as will the Klein Chemistry Laboratory and Yale Biology Building that are currently being designed.

The third floor of Brady Memorial Laboratory, the seventh floor of the Laboratory of Epidemiology and Public Health, and the Yale School of Management — all currently under construction — are targeted toward meeting LEED Gold standards, she added.

While adhering to LEED standards requires an added investment from the University — approximately 2 percent of the overall construction cost is added to the baseline construction cost — Chapman said these buildings yield monetary and environmental benefits for Yale. And for now Yale shows no sign of straying from its LEED commitment.

SETTING THE STANDARD

Yale’s sustainability practices are guided by goals set in its 2003 Environmental Principles, in which the University committed itself to demonstrating “outstanding environmental performance” in the design, renovation and construction of its campus facilities.

LEED did not play a role in furthering the University’s environmental aims until 2005, when the first campus building planned according to LEED standards opened.

Four years later, Yale Facilities established formal requirements for the construction and renovation of campus properties. Those requirements mandated that all future construction projects of “comprehensive scope” — such as the creation or restoration of new buildings — adhere to the standards for LEED Gold or Platinum certification, in addition to meeting other University-specific regulations. University projects of “small or limited scope” do not require LEED certification, but must adhere to basic sustainability requirements set by the University.

Still, several of Yale’s peer universities, such as Stanford and Princeton, do not mandate LEED certification for campus buildings. Stanford, which has a mix of LEED and non-LEED buildings, leaves the decision to the individual school or entity of the building instead, said Fahmida Ahmed, associate director of the Stanford Office of Sustainability.

“We certainly wouldn’t want to force anyone to do it, and we leave it to the discretion of the school who’s the owner of the building,” she said.

Regardless of whether a project ultimately becomes LEED certified, Ahmed said, it tends to meet or exceed the sustainability guidelines recommended by the University. She added that Stanford’s guidelines draw on a variety of practices for which LEED is “a valuable leverage point.”

Chapman said Yale considered other ranking systems but ultimately chose the LEED ranking system because it took multiple aspects of design into account. Renovation and new construction projects are evaluated in five assessment areas: sustainable site development, water efficiency, energy efficiency and atmospheric impact, indoor environmental air quality, and materials and resource selection and use. Extra credit categories, such as innovative design practices or adherence to regional priority credits, can give additional points to projects awaiting LEED certification.

Though not affiliated with the U.S. government, the LEED ranking system is “recognized as the national standard measure of sustainability,” Chapman wrote in an email to the News.

To achieve LEED certification for a structure, project designers typically go through the Council’s checklist to determine how they will achieve the desired number of points qualifying them for a specific ranking, said Kristin Simmons Ferguson, a LEED-accredited professional of the Green Building Council.

Ferguson added that obtaining LEED certification is a way for institutions to demonstrate their commitment to sustainability.

Though the Council does not require the hiring of LEED-trained architects and engineers for projects, she said that constructing new buildings necessitates the consultation of a trained official. The architect, she said, will usually register the project on the Council website and declare the project’s intent on receiving certification. The applications are reviewed twice before they are approved or rejected.

A SCIENTIFIC START

The first college lab in the world to receive a LEED ranking sits near the top of Science Hill, at 275 Prospect St. Named for the Yale class responsible for funding the project, the Class of 1954 Chemistry Research Building opened in October 2005 and achieved silver LEED certification in 2006.

“Laboratories are one of the highest consumers of resources, so they are great opportunities to address our sustainability goals,” Chapman said.

The Building consumes 25 percent less energy than a “standard high-intensity laboratory” of its size, according to a report on the building published by the Office of Sustainability.

To avoid wasting heat, the building’s ventilation system circulates tempered air — which consists of low-temperature air added to a heated airstream — through the offices at carefully calculated velocities. This temperature-regulated airstream then travels to the lab workspaces and is released through reduced-volume fume hoods, said LEED Accredited Professional Patricia Culley, who works for the Bohlin Cywinski Jackson architecture firm that designed the building.

Instead of having preconditioned air for separate lab areas, the Building takes air from the outside, conditions it and uses it to cool or heat the offices. Then, that air, instead of returning outside, circulates to the lab zone, where it ultimately travels through a fume hood and returns outside. Culley added that this system, with only one source of preconditioned air rather than several, reduces wasted energy.

The building’s air flow system further saves thermal energy by capturing heat from the air traveling through the fume hood. This captured heat is used to condition the air entering taken in from outside the building.

This system not only reduces energy use but also ensures healthy air quality, a necessity for safe chemistry research.

In the new building, one can hardly smell any organic compounds, a change from previous chemistry department laboratory setups, said Chemistry professor Robert Crabtree, who has worked in the Yale Chemistry Department since 1977. He added that the building is the preferred facility among chemistry students and researchers alike.

“We users of the building are happy to use it, but we don’t really know the technical details that the architects obviously work out for us,” he said.

While all the labs he has worked in contained fume hoods, he said fume hood positioning was limited in the past — the window could either be completely open or completely closed. The Building’s horizontal and vertical fume hoods allow for the opening and closing of specific panels, leaving a minimal amount of surface area exposed and allowing for more efficient air passage.

Though Crabtree said he had never heard of the term “LEED buildings,” he said building occupants do notice the effects of this sustainable technology.

SUSTAINABLE DESIGN

As Yale’s LEED pilot project, the Chemistry Research Building utilizes several technologies that have since been implemented in other LEED projects across campus. Together, the 19 buildings and lab spaces have contributed two percentage points toward the University’s goal to reduce greenhouse gas emissions by 43 percent of 2005 base levels, Chapman said.

The Building required sustainable design from the start: It was constructed from products like recycled steel and sustainably harvested wood, which comprises 75 percent of the building’s wood content. Nearly three-fourths of the material that resulted from the demolition and the material leftover from the construction was recycled.

Windows in the Yale LEED buildings are positioned to maximize natural lighting. The Chemistry Research Building’s open laboratories were also designed to face north in order to allow the most natural sunlight possible to pass through their tall windows, Culley said. Other features, such as the use of glass enclosures for writing spaces, further minimize the use of artificial lighting by borrowing the labs’ light.

“The sun comes in and makes people feel happy,” Crabtree said, adding that the well-lit facility helps foster a sense of camaraderie and excitement to conduct research.

Windows can also help regulate temperature. Offices located on the south-facing side of the Building contain smaller windows equipped with horizontal solar shading to reduce glare and heat gain during the summer.

To further avoid wasting energy, occupancy sensors turn lights on and off automatically based on the detected amount of human activity, as well as minimize airflow in emptier rooms.

New Haven has also placed its faith in the LEED system. The Elm City currently ranks sixth in terms of LEED-certified buildings in the Northeast and ranks third in the New England region, said Robert Tufts, a business intelligence specialist at the US Green Building Council.

LEED certification is not mandated in Connecticut except in a few cases, but the majority of the Elm City’s recent construction projects — such as Gateway Community College and 360 State Street — have successfully met LEED standards, said Giovanni Zinn ’05, who works as a consultant for the New Haven Office of Sustainability.

New Haven’s education buildings, he added, have set a precedent for the rest of the state — the city is home to the Barnard Environmental Magnet School, Connecticut’s first public school to achieve LEED certification.

“Before LEED really became a thing at all, we brought our own high-performing school specifications that really promoted efficient schools,” Zinn said. “We’ve seen millions of dollars in savings in utility bills in that and all of our energy initiatives in the city.”

DOUBTS, CRITICISM

But not all Elm City residents are as accepting of LEED’s ranking system.

In 2010, New Haven’s Environment & Human Health, Inc. published a study criticizing LEED’s emphasis on energy reduction at the expense of human health.

EHHI President Nancy Alderman said the idea of sustainable, LEED-certified buildings may incorrectly imply a healthy and safe interior environment, so construction projects can achieve the highest-ranked LEED Platinum certification without accounting for toxins such as indoor air pollutants.

“Some of the LEED buildings, of course, are wonderful, but our point was that you could have a building that was not a terrific building that could still be LEED-certified,” Alderman said.

Yale School of Forestry & Environmental Studies professor John Wargo, the report’s lead author, said that although LEED has become one of the nation’s most widely recognized building certification programs, he was concerned by the lack of uniform federal standards for sustainable buildings.

He added that he hopes Yale‘s future projects continue to surpass LEED standards, and take typically undervalued LEED criteria — such as controlling hazardous material used in building products and improving methods of exchanging outdoor and indoor air — into consideration.

Environment school professor Arnulf Grubler said the LEED ranking system consists of too many categories of focus, and that not every indicator can be so easily measured.

“The rating of the indicators are at best arbitrary, and at worst, counterproductive,” he said.

He added that the current classification system does not hold buildings accountable for clearly demonstrating how they benefit the environment over time. The Green Building Council does not require already LEED-certified structures to re-apply for the title, said Ferguson, who works for the Council.

“LEED is largely a design of constructing a building and doesn’t check how the building performs over its entire lifetime,” Grubler said. “My perspective is it is the performance of the operation phase of the building that dominates its environmental footprint over its entire lifetime because buildings are just here for such a long time.”

LONG-TERM INVESTMENT

Chapman said she sees LEED buildings as a long-term investment in Yale’s financial and sustainable future.

Nationwide, buildings account for almost three fourths of energy consumption and over a third of energy use, carbon dioxide emissions, and raw material use, Chapman said. Buildings, she added, produce 30 percent of waste output — 136 million tons annually — and account for 14 percent of potable water consumption.

As Yale’s campus continues to expand, she said, LEED buildings consistently use energy efficiently, which contributes to the University’s goals of reducing energy, conserving water, recycling and improving air quality. LEED technologies and building practices, she said, include features which reduce the environmental impacts of these buildings.

The impact of Yale’s LEED buildings may not be quantifiable just yet. But with just a year left as Yale approaches its 2013 deadline for accomplishing the goals outlined in its 2010-’13 Sustainability Strategic Plan, the University will once again evaluate how successful a role LEED buildings play in helping the University meet its goals.