Photography: Wes Thompson

Glazing Contractor: Enclos Corporation, Minneapolis, MN
Laminator: Viracon, Owatonna, Minnesota
Interlayer Manufacturer: Solutia Inc., St. Louis, Missouri
Architect: Dworsky Associates, Los Angeles, California
Blast Consultant: Weidlinger Associates Inc., New York, NY
Project Completion Date: Spring 2000

The Las Vegas Federal Courthouse, one of the first federal courthouses to be completed since the Oklahoma City bombing, blends an open and inviting glass facade with state-of-the art security measures. The building looks nothing like the fortress it is, and its designers say it could fare better through a bomb attack similar to the attack on the Alfred P. Murrah Building in Oklahoma City.

The 407,000-square-foot facility is located on Las Vegas Boulevard in the center of the downtown business district. The $97-million project includes 10 courtrooms, judicial chambers and various state offices. It is the first building to incorporate the federal government’s new anti-blast design standards, which were developed after the Oklahoma City bombing.

The additional security measures, which include blast-resistant glazing and floors designed not to collapse on each other, added about $5-million, or 5 percent, to the overall construction cost for the building. The lead designer on the project used laminated glass with a polyvinyl butyral (PVB) interlayer in the curtain wall instead of the annealed glass used in Oklahoma City’s Murrah Building.

In the Las Vegas Federal Courthouse, light flows through the two seemingly conventional double-glazed walls, which are actually unitized panels of aluminum frames and one-inch-thick insulated panes of laminated glass with a PVB interlayer. A glass dome tops the structure, which is also blast resistant. The General Services Administration (GSA) gave the designers a tall order — the new structure needed to protect the interior occupants from a terrorist’s bomb — but left the execution of the assignment in the hands of the design team. Armed with the knowledge gained from Oklahoma City’s massive glass damage, a blast-resistant curtain wall was designed, fabricated and installed to help heighten the level of protection for the building. The entire design team agreed that full-scale testing would be required, marking the first time a curtain wall was subjected to such rigorous blast testing. Two full-scale specimens were used for testing at the government’s White Sands Missile Range in New Mexico. Two systems were tested using laminated glass with a PVB interlayer attached to an aluminum frame, and subjected to another test where the glass was attached to a steel truss framework.

The units are integrally connected to the building frame, rather than clipped on. Compared with the simple construction of the Murrah Building in Oklahoma City, the steel frame is more ductile and has greater energy dissipation capacity. Exterior design elements, such as landscaping and concrete barriers, are also designed to keep explosive laden vehicles from getting near the building.