June 11, 2020
Bowdoin College, Brunswick, Maine, aims to inspire students and faculty to work toward a greener tomorrow with the addition of its three-story, 2710-m2 (29,167-sf) Roux Center for the Environment. The center’s silicone-glazed, fire-rated steel curtain wall is one example where stunning transparent lites of glass also support daylighting and views of the tree-strewn town.
Framed by stately white pines, the Roux Center harmonizes the natural with the manmade. The building’s thermally modified lumber cladding pairs well with eye-catching glass-paneled expanses. Along with sustainable aesthetics, the center sought to achieve Leadership in Energy and Environmental Design (LEED) Platinum certification.
The college tasked architecture firm, Cambridge Seven Associates (C7A), with designing the Roux Center’s classrooms, teaching labs, research labs, faculty offices, conference rooms, and common spaces/corridors for optimum daylight, quality views, and enhanced collaboration.
During this process, an interesting dynamic arose: the dual need for compartmentation and transparency to promote occupant well-being. To promote safe egress for students and faculty in the event of a fire, it was necessary to ensure the exterior façade on the Roux Center’s exit stairwell provided fire resistance. However, many opaque forms of standard fire-rated building materials, like concrete and gypsum, limit light transfer and views—both of which are essential to LEED Platinum certification.
C7A overcame this challenge by incorporating a silicone-glazed, fire-rated steel curtain wall with fire-rated, impact safety-rated glass firewall for the stairwell’s exterior façade. It brings the building up to code, while preserving daylight and views for occupants, supporting environmental considerations.
Both the frames and fire-resistive-rated glass block the transfer of radiant and conductive heat. The Underwriters Laboratories (UL)-classified system acts as a barrier against high temperatures, along with smoke and flames in a fire situation. Should flames engulf the stairwell, the curtain wall also acts as the ultimate safety monitor for up to two hours. This allows first responders more time to arrive at the scene, while seeing students and staff safely out of a burning building.
Along with compartmentation, design considerations were equally important to the project. The fire-rated curtain wall resembles the glass used along the structure’s main entrance, creating a uniform look. Its toggle retention system helps achieve clean sightlines that match the seamless aesthetic of the neighboring silicone-glazed (SG) curtain wall system. The toggles eliminate the exterior pressure plate, while still retaining the glass. The fire-rated system also uses a captured perimeter and verticals, with uncaptured horizontals to finish out the recessed section on the exterior façade and the exit stairwell.
The result is two complementary curtain walls, matched by their tall, free spans of glass and slender profiles. In application, the large lites of glass invite ample daylight into the exit stairwell. Sunlight pours into the space, and illuminance increases student and faculty well-being, while ticking off LEED daylighting requirements. The curtain wall’s slim, minimal profiles further offer less-obstructed views, connecting building occupants with the outdoors and helping earn indoor environmental quality LEED points.
The Roux Center’s smooth, continuous, fire-rated glass façade opens up the stairwell visually to a sea of green, red, or gold-leaved trees, depending on the season. Large spans of fire-resistive glass flood the interior with natural light. The fire-rated system mirrors the non-rated curtain wall, and is a case in point that fire and life safety no longer compromise design.
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