Last year, renovations to the Federico Degetau Federal Building and the Clemente Ruiz Nazario U.S. Courthouse in Puerto Rico were completed as part of a project aimed at helping protect federal government offices and occupants while preserving the modern aesthetic. The project was one of several funded in Puerto Rico by the Federal Government; the window replacement was funded as part of the U.S. General Services Administration’s (GSA’s) Security Enhancement, Glass Fragmentation Program.

Located on a 26-acre campus in the Hato Rey section of San Juan, the Federico Degetau Federal Building houses more than a dozen federal agencies; connected to the federal building with a 1,600-square-foot addition, the Clemente Ruiz Nazario U.S. Courthouse spans 100,000 square feet.

Both buildings were designed in the 1970s by local architects O’Kelly, Mendez & Brunner and Miami-based engineers Smith, Korach and Associates. To keep the exterior upgrades for both buildings historically appropriate, the GSA hired Wank Adams Slavin Associates LLP (WASA/Studio A) as the project architect and Weidlinger Associates as the structural engineer. Wausau Window and Wall Systems provided six types of high-performance systems for the job and glazing contractor Koch Corporation of Louisville, Ky., performed the installation.

“I think that the biggest challenge that we faced on this project was responding to the variety of performance requirements called on for the new windows, including blast- ballistic- and hurricane-resistance, all combined within operable units, and on a building of an increasingly recognizable architectural character,” said WASA/Studio A’s senior associate for preservation, Angel Ayón, LEED® AP. “Glazing for blast-resistance requires some degree of resilience to accommodate the positive and negative pressures exerted by the blast load, whereas ballistic and hurricane resistant glazing ought to be stiffer to be able to absorb the impact loads. For the untrained, these requirements may seem contradictory at a glance, but a thorough understanding of the load combinations permissible under the government’s security criteria, and close collaboration with both the blast engineer and the window manufacturer, allow the architect to provide for all these requirements without sacrificing performance, operation or appearance. At the FOB and US Courthouse in Hato Rey, these requirements were addressed by providing concealed steel reinforcement and heavy duty anchorage along the thermally-broken aluminum frames, along with silicone-glazed, low-E coated, laminated IGUs and multi-point locking mechanisms at the operable sashes.”

The windows’ appearance was an equally importanta factor and the window systems provided by Wausau were designed to closely resemble the original architectural character with narrow sightlines.

“For us at WASA/Studio A, it was critical that we … [minimize] the impact of the replacement windows on the building’s historic character. That’s why, from the project outset, we aimed at not exceeding the existing window sight-lines. In doing so, we avoided heavy-looking, bunker-like replacement window assemblies that would have otherwise distracted from, and therefore be detrimental to, the building’s original aesthetic,” Ayon said.

The buildings remained fully occupied and operational throughout the renovation and the window replacement portion of the project took two years. It was completed in May 2012, despite interruptions in the form of two tropical storms and two hurricanes making landfall at the site all within the span of 14 months.