Architects Merge Form, Function in Oklahoma City
Architects Merge Form, Function in Oklahoma City
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Southeast corner of the Federal Campus in Oklahoma City, OK |
Entering the new Oklahoma Federal Campus that replaces the Alfred P. Murrah Building destroyed in the 1995 terrorist bombing one can’t help but be impressed by the vast expanses of glass welcoming sunlight into the building. Because of the liberal use of glass used in the design of the building it looks nothing like the stronghold it is.
“Security was paramount when designing the campus, but we also wanted to create a sense of openness in a sustainable building,” according to lead designer, Carol Ross Barney of Ross Barney + Jankowski, the Chicago-based architectural firm that designed the Federal Campus. “The generous use of glass in the building design allowed us to accomplish all these objectives. We wanted a safe, but not prison-like building.”
The design of the new 181,000 square foot, three-story building, which opened in December, 2003, embodies a balance between solididity and openness by contrasting exposed concrete and punched windows with large protected areas of curtain wall in a sweeping elliptical courtyard. Striking colonnades complete the urban rectangular footprint, separating the building from the street and creating physical and emotional security. The expansive use of laminated glass, made with interlayers from Solutia Inc, creates an open airy impression.
After the bombing of the Alfred Murrah building and subsequent bombings around the world, the use of blast resistant windows was thrust to the fore-front in the design of government buildings.
More than 75 percent of the injuries related to the Oklahoma City bombing were due to flying or falling glass. “Without compromising the open and inviting look and feel of the building, we needed to ensure the Federal Campus provided a safe and secure environment for its occupants. The need for high performance security glazing was evident,” explained Ross Barney.
Glazing contractors Masonry Arts, who also designed, fabricated and installed replacement windows in the Pentagon, selected blast resistant laminated glass, made with Solutia’s Saflex protective polyvinyl butyral (pvb) interlayer. Saflex is bonded with heat and pressure between two panes of glass. The glazing configuration was used in the design of both the curtain wall and punched windows in the new Federal Campus. Upon impact from a bomb explosion, the glass itself may crack, but the fragments tend to adhere to the Saflex protective inter-layer and the glass tends to remain in its frame. By keeping the glass in place, protection from flying glass is provided to people both inside and outside the building.
“To resist the blast resistant loads, the architect chose galvanized steel as the exposed, structural framing components for the windows and curtain wall system,” asserts Sr. Project Manager, Robert Grosze of Masonry Arts. “What was really unique to this project design was the decision to expose the concrete and steel framework.” Typically, structural components are concealed behind applied finishes of the façade. Continues Grosze, “We knew the Oklahoma City community wanted a secure, robust building. The exposure of these fundamental components was a way to visually enhance the secure elements of the building, while still maintaining the open feel of the space that the architects had conceptualized.”
The design of daylighted space requires a combination of form and function, says Ross Barney. “One of the most important design challenges was finding a way to use glass in a distinctive way, while admitting only as much light as necessary and distributing it evenly throughout the space…without introducing glare or heat.” Ross Barney used a clever combination of tinted and clear glazing to meet this challenge. Most of the glazing in the building extends from floor level to ceiling at 11 feet about finished floor. The glass from floor to eight feet is tinted to reduce glare in the workspace. At the eight foot level the architect has provided a horizontal lightshelf of white vinyl coated fiberglass awning material. These light shelves shade the glass below from direct sunlight and reflect this light through the clear glass in the band from 8 to 11 feet above the floor and onto the ceiling for a deeper and more uniform distribution. The use of awning material for the lightshelves is twofold, noted Ross Barney. The material is lightweight, thus reducing loads coming to the curtain wall framing. Further, in the case of a bomb blast, the risk of injury or damage from this lightweight material is greatly reduced as compared to other more solid materials.
Perhaps the greatest testimony to the extraordinary measures taken to ensure the highest possible safety standards in the design and construction of the Federal Campus comes from Aren Almon-Kok, founder of Protecting People First Foundation (PPFF). Almon-Kok is mother of Baylee Almon, one of 19 children killed in the 1995 terrorist attack. The photograph of Baylee’s lifeless body being carried from the debris in the arms of a fireman became a world-recognized symbol of the Oklahoma City bombing. Says Almon-Kok, “I learned firsthand how dangerous glass can be. I have testified before Congress on the need for safer buildings. I have seen what security measures have been taken in constructing the Federal Campus and I wouldn’t hesitate to put my own children in the building.”
For more information, visit: http://www.Solutia.com.