Leers Weinzapfel Associates completes America′s first cross-laminated timber academic building



The first and largest cross-laminated timber (CLT) academic building in the U.S. opened in 2017 at the University of Massachusetts (UMass) Amherst. Designed by Leers Weinzapfel Associates, the multi-disciplinary Design Building brings together 500 students and 50 faculty across four departments into a light-filled 87,000-square-foot space. As a beacon of sustainability, the building features energy-saving elements, such as chilled beams and radiant flooring, and targets LEED Gold certification.

The Design Building, which brings together three related departments under one roof, was originally designed with a steel structure, but the Building Technology faculty had other ideas. Perceiving the building as a potential demonstration project and sustainable teaching tool for the state university, they urged the team to apply their area of research and innovation, engineered timber, instead and consider advanced timber/CLT construction.

Their initial suggestions were met with resistance because it was anticipated that using wood would incur a cost premium for an already tight budget. Yet the faculty members persisted, engaging the assistance of a local former U.S. Congressman to persuade his colleague in the State legislature to earmark funds for this important demonstration project. They also recommended a key design engineer in Vancouver BC who had experience with the design of CLT structures. These efforts paid off, resulting in the necessary commitment, and the building was adapted accordingly during the design development phase.

The news of this important sustainable demonstration project spread quickly through the UMass community and was embraced at the highest levels of the administration. As such, the project has become a ready model for future building at the university and by its groundbreaking, excitement about its potential was palpable.

Cross-laminated timber
CLT has long been praised for its durability, lightness, and speed of construction, however, has been slow to catch on in the U.S. relative to Europe and Canada. As the largest installation of wood-concrete composites in North America, the Design Building paves the way in the growing trend of ‘mass timber’buildings. Cast-in-place concrete and CLT make up the Design Building’s floor slabs, while glue-laminated timber was used for the posts, beams, shear wall cores, and ‘zipper’ trusses. As the first academic building in the U.S. to use to use timber for every major structural system, the building contains 52,500 square feet of wood concrete panels – installed from the second floor to the fourth floor. The first floor is polished concrete whilst the basement floor is unpolished concrete. Glue-laminated timber was usedfor posts, beams, shear wall cores and ‘zipper’ trusses (so named because they converge multiple structural members to a single point).

Targeting LEED Gold
Bringing together the previously dispersed departments of Landscape Architecture, Architecture, and Building Technology programs, the new Design Building is a dynamic space of exchange, collaboration, and experiment, celebrating a shared commitment to sustainability. As a highly visible demonstration of sustainable design practice, it is the first and largest CLT academic building in the U.S. The envelope is highly-efficient, with dedicated mechanical equipment zoned for maximum efficiency, with radiant flooring and chilled beams for energy savings.

“We imagined this building as a teaching tool for the design disciplines,” said Andrea Leers,a principal at Leers Weinzapfel. “I know from my own teaching experience that there’s nothing more potent than being able to talk with students about the space around you.”

Calculated expanse of glazing and skylights provide maximum daylight to the building’s interior to significantly reduce artificial lighting energy. The storm water management concept directs roof runoff via sculptural scupper to a ‘spring source’ at the top of the site and filters the water via a series of successive bio-swales and timber dams to the lower end of the site and eventually back to the Connecticut River.

To create a center space of collaboration, a coiling and rising band of studios, faculty offices and classrooms surrounds a skylit Commons for gathering and presentations. The building also forms a green roof terrace, a contemplative space shared by the studios and faculty and a potential experimental space for the landscape department.

The slope of the site creates a tall four-storey facade on the west facing the mall, and the rising structure invites the community into the building and reveals the activities within. The east side of the building faces a series of smaller historic buildings along Stockbridge Way, and its three storey facade fits comfortably into this context. A durable envelope of copper colored anodized aluminum panels and vertical windows suggest the color and patterns of forest and trees of the region. A highly innovative engineered timber structure makes this an example for the sustainable use of wood and builds on the leading-edge research of the Building Construction Technology program.

Now occupied, the design building is beginning to fulfill its promise as a teaching tool for each of its disciplines. The architecture program can show students how the configuration of space enhances collaboration and experiment, provides important connections to the campus, and integrates a high level of sustainable design thinking. The landscape architecture program will point to the environmentally responsible site development including water management and upper courtyard teaching spaces. And the building technology program will enjoy a full-scale example of its research in integrated wood and concrete construction.

The USD 52 million project was partly funded by the Massachusetts State Legislature. Today, the building sits among several arts-related buildings at the university and looks over a quad. “Positioned in the center of campus, the building is a critical link in the university’s arts necklace,” concludes Steve Schreiber, Professor and Chair of the Architecture department.

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