Great Glazing: Columbia Theological Seminary

Photos by Jonathan Hillyer / Atlanta

The basics: An 80-foot-tall glass, steel and masonry bell tower is the centerpiece of a new classroom building at Columbia Theological Seminary. The $8.2 million building, named the Vernon S. Broyles Jr. Leadership Center, connects a 20,500-square-foot repurposed historic dormitory, built in 1932, with 16,000 square feet of new construction to create what is now the seminary's primary classroom building, and outdoor learning and gathering space. The structure features a contemporary feel, while maintaining the historic collegiate gothic architecture of the seminary's other buildings, according to officials from Lord, Aeck & Sargent, the building architect.

In order to knit together the old and new construction, LAS designed the glass tower element to serve as a visual nexus to provide an entry into the complex and to accommodate new vertical circulation, thus addressing the accessibility issues of the existing structure. The tower contains an elevator to serve the existing three-story Simons-Law wing, a new entrance lobby, and study balconies, with expansive views of the campus. It also can be seen from most locations on campus, greatly improving the visibility of the seminary, according to LAS officials.

The project earned Gold certification from the U.S. Green Building Council's Leadership in Energy and Environmental Design program.

The players: Architect, Lord, Aeck & Sargent; construction manager and general contractor, New South Construction; glass fabricator, Viracon; low-iron glass manufacturer, PPG Industries; glazing system supplier, YKK AP America; glazing contractor, Southeastern Glass & Metal.

The glass and systems: The majority of the tower glass consists of PPG Starphire low-iron insulating units to provide extra clarity and transparency through the tower. For the decorative glass in the tower and in the big corner gables, architects specified patterned, heat-strengthened insulating units with ceramic frit in blue, green, red and yellow. The majority of the glass for the rest of the project is clear insulating units with low-emissivity coating on the No. 2 surface. In select locations in the low clerestories on the exterior wall, a tinted low-E insulating glass unit was used, with a visible light transmittance of 25 percent to provide appropriate light levels on the projection wall on the classrooms.

The architect did extensive studies to determine the location of the tinted glass, the relationship of higher gable glass and direct light blocking baffles, and to determine the appropriate balance of glass to solid wall in order to daylight the space and provide the requirements for the A/V system. The colored glass areas were designed with a rotating pattern that balances the colors throughout the crosses. The blue was used as spandrel so the structure could be seen beyond and continue the feeling of transparency, according to LAS officials.