A Snake in the Glass

wausauThe beauty of Salt Lake City’s Public Safety Building may sneak up on you. Attribute it to the serpentine glass curtainwall used in the LEED-Platinum designed building’s construction. The brainchild of Salt Lake City-based GSBS Architects, the serpentine glass curtainwall slopes from one wing to the other. Additionally, the design called for the curtainwall to cant in multiple directions.

But the Public Safety Building wasn’t designed with just aesthetics in mind. In addition to its modern style of architecture the building’s glass exterior needed to meet seismic and ballistic requirements, as well as contribute to the building’s LEED and net-zero energy objectives.

General contractor Okland Construction and glazing contractor LCG Façades selected Wausau Window and Wall Systems to help with the curtainwall production.

“LCG Façades was brought in early in the design phase to answer GSBS Architect’s number one question: ‘Can a curtainwall system segment and cant backward at 15 degrees and then change angle, while maintaining the cant through a reverse S curve?’” says Ted Derby, business development manager at LCG Façades. “We thought with Wausau’s help, we could make it happen. As soon as we received a wire frame 3-D model, we sent it to Wausau, and they came back with a conditional, but affirmative statement that they could make the design a reality. Shortly afterwards, Wausau and LCG Facades entered into an agreement to work together on the project.”

For the Public Safety Building’s lobby and main floors, LCG installed more than 32,000 square feet of Wausau’s INvision™ Thermal Unitized Curtainwall, including 19,150 square feet of 7250i-UW Series and more than 13,000 square feet of 6250i-HRX Series. INvision products combine the benefits of natural light and outside views with the recognized performance and recycled content that may aid buildings seeking LEED certification. The selected INvision systems incorporate polyamide thermal barriers that enhance system thermal performance, condensation resistance and energy efficiency.

Eric Alexander, project manager for LCG Façades adds that, “It was a very complex curtainwall layout so a lot of the challenge came in the up-front design, leading into fabrication of individual parts. There were very few like parts … because of the way the wall rotated. It had a really beefed up seismic requirement … so the preparation for that was challenging. About 40 percent of the exterior is bullet resistant.”

Along with the curtainwall, LCG Façades installed nearly two dozen Wausau 4250-Z Zero Sightline casement windows on the building’s upper floors to support the project’s goals for natural ventilation and a connection to the outdoors for occupants. Also contributing to the Public Safety Building’s net-zero energy goals, Wausau engineered and installed Clear Story™ interior light shelves and sun shades to allow light to penetrate deeper into the interior spaces.

The aluminum frames, light shelves and sun shades contain recycled content averaging 70 percent or greater. Linetec finished these aluminum components in “MC Platinum” using a two-coat, 70 percent fluropolymer mica flake paint.

Viracon fabricated the high-efficiency, triple insulating glass used in the curtainwall and the low-E, insulating glass installed in the casement windows. In some curtainwall units, three different thicknesses of glass were needed to provide the security required for the project.