This new home for a graduate school of forestry and environmental studies at a prominent university had ambitious goals, among them: being the flagship of the institutions commitment to sustainable practices and energy conservation; to be novel and inspiring while fitting in with its Neo-Gothic neighbors; to be memorable on a campus known for its architectural icons; to provide a home for an academic department previously scattered throughout a collection of outdated buildings; to not only be sustainable but to explicitly reveal through its design how a building with a 100-year lifespan can operate on nearly 60 percent fewer resources than its conventional peers. It would change the way the university built buildings, and hopefully inspire and challenge other institutions as well.
The Yale School of Forestry and Environmental Studies includes offices for faculty, classrooms, a library and study center, an auditorium, a student lounge, and a service node for the entire academic neighborhood. Located on a sloping brownfield site previously home to a gritty power plant and a forgotten courtyard that was an eyesore, the new building capitalizes on its proximity to both a revered campus neighbor designed by an iconic architect and a venerable grove of trees.
A modernist blend of a cathedral nave and a Connecticut barn, the building is long and thin, sited to admit heat from above and below ground, daylight, and air as well as to create outdoor spaces for practical and aesthetic purposes. Ohio sandstone exterior walls connect Kroon to similarly clad colleagues on the main campus, while the fir louvers on either glass end of the building announce a new and practical aesthetic. The honey-colored Kroon cheers up its neighborhood considerably, in part, with a broad welcoming outdoor lobby facing the street, while a walkway nearby lures pedestrians into an expansive courtyard one of two new greenswards that does double duty as a green roof above a new service node for the entire Science Hill environs. To the east, the mature hardwood canopy of Sachems Wood beckons travelers into the heart of the science campus.
The greenest of all its Yale colleagues, Kroon Hall was designed to use 58 percent less energy than comparable peers and is certified LEED Platinum by the U. S. Green Building Council garnering 7 more points than the requisite 52. The inclusion of elements and features that would provide both passive reduction of energy use and active, on-site renewable energy was important to the design team. Centerbrook as Executive Architect collaborated on the project with the Design Architects, Hopkins Architects of London, and an all-star team of consultants that included ARUP engineers, atelier 10, Nitsch engineering, Kalin Associates, and Olin Partnership.
Sustainable initiatives are highlighted by photovoltaic roof panels, deep geo-thermal wells, solar hot water heaters, abundant insulation walls are rated at R-29 and the roof at R-43, automatic daylight dimming, maximum use of natural ventilation and thermal energy exchange, displacement air systems, indirect evaporative cooling, built-ins for recycling, and use of green building materials. North and south faades feature deeply recessed windows and highly insulated stone veneer walls, which combine with significant thermal mass within the building to provide effective climate control year round. The building consumes 81 percent less water than a conventional peer through conservation waterless urinals, dual-flush toilets, and other features and rainwater harvesting for sanitation and landscaping uses. The site features an innovative application of rainwater treatment, storage, and reuse: a landscape water feature that uses plants to cleanse storm water through phytoremediation. Treated overflow is directed to a subsurface 20,000-gallon storage tank, from which it is continually recycled through the manmade pond. The system is projected to save 634,000 gallons of water annually.
The open central stair allows for stack-effect ventilation between levels. Indirect adiabatic cooling and heat exchangers recover 75 percent of energy from exhaust air, and four ground-source heat pumps help regulate interior conditions. An integrated solar array on the roof generates 25 percent of the buildings energy. Lighting throughout is high-efficiency and is controlled by occupancy sensors, and most fixtures are fluorescent or LED. Building energy use can be monitored by occupants at all times via two touch-screen monitors in the lobby. The extreme variation of local climate necessitated an adaptable building that could be completely closed to the outside during the summer and winter months, yet open to allow for natural ventilation during the transitional seasons to minimize energy use.
Kroon Hall is part of a larger plan to systematically transform the social and physical environment of the surrounding science neighborhood. Its broad pathways, runoff pond, and greenswards provide a park-like way station for perambulating students and passersby. The new structure proudly addresses the busy main boulevard to the west while connecting to an historic urban wood to the east through its main south courtyard. The site features twenty-five varieties of native, adaptive plantings.
The buildings narrow floorplate provides natural light to a large percentage of spaces and allows effective cross-ventilation via operable windows and Silenceair boxes above doors. Program spaces are prioritized so frequently occupied areas have the most access to daylight while auxiliary spaces are located centrally. Indicators tell occupants appropriate times to open windows. Interior climate is maintained via displacement ventilation and indirect evaporative cooling, significantly reducing energy consumption and increasing user awareness of energy usage. Interior climate is adjustable individually in offices and classrooms, and MEP controls are metered and serviced seasonally to optimize performance. A central open stair with skylights above provides visual and physical connection between all levels of the building. The top floors high ceiling aids with air circulation and helps with daylight penetration. The east and west faades have timber louvers and large overhangs that shade curtain walls while maintaining views. Large, efficient windows allow views out to the surrounding buildings and new courtyards and terraces, which are accessible from various locations in the building and designed with seating to encourage people to study and relax outside. The ground floor cloister encourages outdoor activities even during inclement weather.