Anonymous Hall Faculty and Graduate Student Center at Dartmouth College in Hanover, N.H., is named for alumni and friends who have quietly supported the college for more than two centuries. The $28 million project reuses and adds to a vacant 1960s library, transforming it into a vibrant administrative and social center for the Graduate School of Arts and Sciences, as well as a communal hub for the area. Designed by Leers Weinzapfel Associates, Boston, the 32,995-square-foot project is close to net zero energy use.
Renovation and adaptive reuse of a 1960s building approaches net zero energy
Photo: Albert Vecerka
Campus Renewal
The library is centrally located in the heart of the siloed north campus quad, among 1960s medical school buildings. Part of a wider campus renewal plan, the project, which also includes new entrances for surrounding structures, a wide pedestrian bridge, and new circulation between buildings, transforms an isolated edge of the college into a well-scaled and inviting north quad. The goal was to create an accessible, seamless link between the north campus and the historic green and main campus, allowing it to be shared with undergraduate sciences.
Formerly known as Dana Hall, the addition was made possible by the demolition of an adjacent unused laboratory. The addition reorients the building to create inviting campus connections to the south. As Leers Weinzapfel principal Josiah Stevenson, FAIA, LEED AP, explains, the entry faced the medical school quad to the north. “Through the demolition of an adjacent unused lab building, the new orientation for it opened up to the south and became a gateway to the north quad. We created a south-facing arcade with a plaza and hill for overflow from the new building’s cafe and a bright, warm gathering space for New Hampshire shoulder seasons.”
The new social center of the north campus, the addition houses the lobby and a cafe with an adjacent terrace that overlooks a green. A spiral object stair, visible from the south lawn, ties the building together. The upper floors house the collegial faculty offices, classrooms and places for interactive student gathering, while the rooftop level features a solar-paneled canopy and south-facing planted terrace overlooking the Vermont hills, Baker Tower and the iconic main campus. The lower level features a walk-out graduate student lounge that opens to a protected courtyard below a pedestrian bridge.
Photo: Albert Vecerka
Design Strategies
The original Dana Hall was a two-story, brick-clad, cast-in-place building built in 1962. In 1971, a brick-clad steel addition added a floor, penthouse and cantilevered projects. Before construction began, the building was stripped to its columns and slabs to remove hazardous materials in the existing library walls. To bring the building up to modern codes and allow for reprograming, the design strategically added a new combination of shear-core and braced-frame lateral systems and attached a steel-framed addition at the south.
Working within a tight construction budget, the architects used five highly effective strategies to reduce the building’s energy footprint. These include the reuse of the original concrete and steel structure, highly insulated walls and roof, ultra-high-performance glazing, an energy-efficient, space-saving mechanical system and a photovoltaic shading canopy. Together, these reduce the energy used in construction and reduce the building’s predicted energy use by 90% compared to baseline.
By reusing 20,000 cubic feet of the existing concrete structure, the architects were able to save more than 1,200 metric tons of carbon from the concrete alone. Insulation also provided a cost-effective, energy-efficient measure. The lightweight, stud-framed exterior walls combine 6 inches of continuous dual-density stone wool insulation with 5 1/2 inches of stone wool batt in the cavities to provide a U-value of 0.033, double the code required thermal resistance. The roof system provides a minimum R-60 continuous insulation with an average effective U-value of 0.014, almost triple the code required thermal resistance.
Additionally, a radiant heating and cooling system with dedicated outside air and fan-assisted natural ventilation is used to provide ventilated air in volumes and as-needed to spaces. Manual and automated windows allow natural ventilation, further reducing energy use, and the 67kw photovoltaic panel canopy, which covers nearly the entire existing roof area, reduces the building’s predicted energy use index (pEUI) from 25 to 10 kBtu/sf/yr.
Photo: Albert Vecerka
A Unique Facade
The building’s facade, which is made up of a variety of advanced technologies including vacuum-insulated panels, krypton-filled triple-glazing, metal mesh integral shading and toggle-held structural glazing (2-inch IGUs), is the first-of-its-kind in the United States.
According to Kevin Bell, AIA, senior associate at Leers Weinzapfel, the facade system brings proven glass and curtainwall technologies together in a new and novel way. “Each element was selected for its ability to increase the overall performance of the system and its ability to improve comfort for occupants of the building,” he explains. “The framing structure is a unitized extruded aluminum system with steel reinforcing at the double-height space. Glass units are silicone, structurally glazed to subframes toggle held to the main framing members. The glass facade panels are a combination of 2-inch-thick, triple-glazed, krypton-filled, four-light vision units and opaque units incorporating high-performance vacuum insulated panel technology. All of the panels include an expanded metal mesh just behind the outer light that reduces solar heat gain and diffuses light to the interior. Operable units are incorporated into the opaque panels and distributed across the facade to maximize natural ventilation potential and overall light levels within the space behind.”
Bell adds that the 3-D quality of the expanded metal mesh blocks more of the summer sun and allows more of the winter sun into the social spaces on the second and third floors, reducing glare and creating a comfortable and sunny space. The fourth floor, which is set back a bit, is clad with formed metal wall panels to create a quiet backdrop to the roof terrace. At the ground-floor entry terrace, exposed steel is protected by a duplex system of galvanized and factory-applied coating. Additionally, the terrace is encased in stainless steel covers as part of the project’s prefabricated fireproof columns.
“Overall, the project tries to match smart design decisions at each scale with components and systems that support the goal of providing a high-quality environment for teaching, research and collaboration with a low-energy impact,” says Bell. “We think the project succeeds in doing just that.”
