Less than a year after its completion, Kroon Hall has received the highest energy rating possible for sustainable design. The new home of the Yale School of Forestry & Environmental Studies on Science Hill was awarded the Leadership in Energy and Environmental Design (LEED) Platinum certification by the U.S. Green Building Council, a non-profit that focuses on sustainable building, on Jan. 28.
“The faculty and students of our environment school are working in a setting that superbly embodies their aspirations,” said President Richard Levin. “We hope Kroon Hall and all of Yale’s efforts to operate a sustainable campus encourage other institutions and governments to take the steps necessary to reduce greenhouse gas emissions and safeguard the environment.”
Kroon Hall was designed to use 81 percent less water and 58 percent less energy than a comparable building and to generate 25 percent of its electricity onsite from renewable sources. Designed by Hopkins Architects and Planners, in collaboration with Centerbrook Architects and Atelier Ten Environmental Designers, Kroon Hall incorporates a wide range of sustainable strategies and design features reflected in its maximum LEED rating, according to a Yale release.
Kroon Hall earned 12 out of 14 possible points in LEED’s Sustainable Sites category through environmental sensitivity to the building landscape design and the promotion of public transportation. Kroon Hall was built on a pre-developed site, following the campus master plan to develop Yale’s Science Hill and the large open space surrounding the building. The site materials, such as light-colored concrete and the south courtyard’s green roof, were chosen to combat the urban heat island effect.
Kroon Hall earned all 5 LEED points for water efficiency by incorporating many innovative water-saving and water-reusing features. Kroon Hall’s potable water usage is 81 percent below that of a comparable baseline building. Stormwater is collected from the roof and courtyards and filtered through native aquatic plants. Wastewater collected from sinks and showers is added to the stormwater and used for all nonpotable needs such as toilets and irrigation. Water demand is further reduced by the installation of low-flow plumbing and irrigation fixtures.
Energy and Atmosphere
Kroon Hall earned every point in the Energy and Atmosphere category for building commissioning, reducing the use of harmful refrigerants, onsite renewable energy production, building energy performance and measurement and verification. Kroon Hall uses 58 percent less energy than a comparable building of a similar size. The building earned 10 points for energy performance and 3 for onsite renewable energy. The rating was achieved through passive design, optimized lighting and incorporation of renewable energy sources onsite.
The east-west orientation of the building takes advantage of solar access and natural ventilation. The building is highly insulated and a green roof serves as a courtyard and covers a service node and storage rooms below. Fresh air ventilation and free cooling cycles on air handling units reduce the need for air conditioning most of the year. Indicator lights alert occupants when conditions are suitable for opening windows. Concrete walls and exposed concrete ceilings retain heat in winter and help cool in the summer.
Displacement ventilation and indirect evaporative cooling condition the spaces using 75 percent less energy than a typical building. In winter, the heat recovery system warms the air using available energy from the occupants, lights and appliances first, which is then supplemented by geothermal energy. High-efficiency electric lighting and controls further reduce energy use and the cooling load. All appliances and equipment are Energy Star TM rated.
To offset some of the energy required by the extremely efficient Kroon Hall, solar energy is generated onsite. Solar hot water is used to heat at least 50 percent of potable water. The photovoltaic array on the roof, which is funded in part by the Connecticut Clean Energy Fund, provides approximately 25 percent of the building’s electricity. The all-electric building’s design protects the atmosphere by eliminating all onsite combustion. The ground source heat pumps serve as the building heating and cooling plant and utilize only HFC refrigerants.
Materials and Resources
Kroon Hall achieved 6 points in the Materials and Resources category. Credit is given to the selection of architectural, structural and landscape materials used in the building and for recycling. Points are awarded for the percentage of materials that were purchased from within a radius of 500 miles from Kroon Hall or are made of recycled materials. The project purchased 16 percent of the materials with recycled content and 34 percent from regional sources. Almost 80 percent of the timber purchased for the building is certified by the Forest Stewardship Council.
Indoor Environmental Quality
Kroon Hall was awarded the maximum 15 points for Indoor Environmental Quality. Points are achieved for projects that maximize daylight and have views to the outdoors, use high-efficiency filtration for the ventilation air, give occupants control of their visual and thermal environment and utilize finished products with low concentrations of volatile organic compounds. These features contribute to greater productivity and satisfaction and reduced health-related absences by the building’s users.
Innovation and Design Process
Kroon Hall achieved 4 out of 5 points for innovation and design. The project achieved points for its green education program, green housekeeping plan and exemplary performance for potable water savings. Kroon Hall’s innovative design ensures that occupants see the benefits of sustainable building features first-hand.
Kroon Hall follows Yale’s Sculpture Building as the second Yale project to earn a Platinum LEED certification. Among Yale’s other LEED-certified projects are its Malone Engineering Building, which earned a LEED Gold rating.
The cornerstone of Yale’s commitment to sustainability is its goal of reducing the greenhouse gas emissions from its facilities by 43 percent from 2005-2020, which would bring emissions to 10 percent below 1990 levels. The greenhouse-gas reduction strategy is part of a comprehensive sustainability framework at the university that includes protection of natural ecosystems, conservation of our water resources, recycling of materials and the use of natural, locally grown food in dining halls.