Sunlight streams into the new Oklahoma Federal Campus that replaces the Alfred P. Murrah Building destroyed in the 1995 terrorist blast, creating an uplifting vision of a future filled with hope and renewal. Photography: Brad J. Goldberg

Glazing Contractor: Masonry Arts Inc., Bessemer, Alabama
Laminator: Viracon, Owatonna, Minnesota
Interlayer Manufacturer: Solutia Inc., St. Louis, Missouri
Design Architect/Architect of Record: Ross Barney + Jankowski Architects, Chicago, Illinois
Associate Architect/Engineers: The Benham Group, Oklahoma City, Oklahoma
Blast Consultant: Weidlinger Associates, New York, New York
Project Completion Date: December 2003

The design of the 181,000 square foot, three-story building in the new Oklahoma City Federal Campus, embodies a balance between solidity and openness. The architect defined the disparity between these two concepts by contrasting street elevations of exposed concrete and punched windows with large areas of curtain wall at the angled southeast and northwest faces, and in a sweeping elliptical courtyard. Adding further to the seemingly contradictory terms of security and openness, concrete colonnades complete the urban rectangular footprint, separating the building from the street and creating physical and emotional security for the building occupants. The liberal use of glass in both the interior and exterior creates a warm and inviting space.

To resist blast loads, the architect chose galvanized steel as the structural framing components for the windows and curtain wall system. As for any landmark project, exhaustive research, testing and verification of performance was carried out before the final decisions on material type, installation methods and overall dimensions of products were made. After reviewing the products available, the designers determined that laminated glass with a polyvinyl butyral (PVB) interlayer and special framing system was their best option.

With the façade glazing requirements of the building met, the architects began to explore the use of glass in other spaces. Because the lobby space was somewhat small, the architects needed to create a welcoming environment for a building with such a significant emotional legacy. The answer came from above. To let light flow into the lobby from the dramatic skylights overhead, the architects designed two glass bridges that span the lobby airspace on the second and third floors. Armed with the expertise of the blast consultants on the project, a multi layer glass configuration strong enough to meet not only structural requirements, but able to withstand an explosion in the lobby below, was created.

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. Most of the glazing in the building extends from floor level to ceiling at 11 feet above finished floor. A clever combination consisting of a high performance low-e coating with tinted and clear glazing was used. Viracon, the glass fabricator, provided a proprietary high performance low-e coating with a blue-green tinted glass, which extends from floor to eight feet to reduce glare in the workspace. At the eight foot level, a horizontal lightshelf of white vinyl-coated fiberglass awning material on the façade of the building was utilized. 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 lightweight material used in the awnings would disintegrate easily in the event of an explosion, helping to diffuse the problem of flying debris.