The government building
Photos by Shawn Donovan, Donovan & Associates. The Sarasota Police Headquarters is designed to achieve Silver certification from the U.S. Green Building Council's Leadership in Energy and Environmental Design program. Final certification is pending.
Designing the Sarasota (Fla.) Police Headquarters was a balancing act. For the six-story government building, designers from Architect Design Group Inc., Winter Park, Fla., developed a structure that could achieve high energy performance and sustainability, while offering security against environmental and man-made threats. In the face of the security concerns and green demands, designers looked to glass, specifying a sweeping impact curtain wall.
"Designing an open and inviting police facility that fit well in the harsh south Florida environment was important," says David Crabtree, associate architect, Architect Design Group Inc. "Energy efficiency, daylight and views were critical to our concept, so high performance glazing systems were essential."
In all, the headquarter building features 40,000 square feet of exterior glass and 6,000 square feet of interior glass, with a total glazing value topping $2 million. The project incorporates almost 2,000 energy-efficient impact windows, weighing 300 pounds each. "We think blending of sustainability and impact resistance makes for a better glazing system—they work in tandem," Crabtree says. "No one is specifying single lite systems anymore. An insulating, laminated glazing system gives us the security and energy performance we need. Plus, these systems provide other important benefits such as acoustics and UV light control."
Justin Burkhart, project manager for glazing contractor Key Glass, Bradenton, Fla. , adds, "With the multiple types of high-performance glazing systems, this was an exciting challenge. We had a staff of 15 people dedicated to completing the curtain wall, storefront and interior systems that will offer Sarasota's police officers and visitors the highest level of protection."
The exterior glass alternates between transparent and vision. Viracon, Owatonna, Minn., fabricated the exterior glass, supplying its 1 5/16-inch blue-green insulating, laminated low-E (VE6-2M) impact-rated glass.
The design allows for ample natural daylighting, from the curtain wall and light wells. The light wells are glazed on three sides to maximize daylighting into the corridors. "Natural light is very important in public facilities and particularly facilities where the employees spend a great deal of time inside," Crabtree says. "We have borrowed light via vertical light gardens, clerestory glazing in corridors and glazing at the perimeter of the building. There are both planned and unplanned views that are a product of the layers of glazing utilized." The light gardens, on the interior of the building, shoot light through four stories.
To control heat gain and glare, the architects specified translucent panels on the curtain wall. About 14,000 square feet of the glass features a Polar White interlayer in the insulating laminated units, making the units translucent. The non-vision panels were multipurpose, providing daylighting, efficiency and privacy, where needed. The translucent glass also "creates a cinematic quality when viewing out of the building," Crabtree says. "It was also intended for the building to have various levels of light intensity at night and glow like a lantern on the perimeter of the large public park across the street."
Designers also used white polycarbonate panels on the exterior of the south side of the building as a daylighting control. "The serve as a brise soleil, or solar shading device, for the harsh southern sun, and provide additional impact protection as well," Crabtree says. "Most of the floors with the polycarbonate panels have an open office just behind, so it also helps to reduce glare and provide for a sense of privacy." On the first floor, the glass walls also incorporate a translucent ceramic frit to provide additional security and privacy for officers at night.
Additional daylighting controls were value-engineered out of the design, including 10-inch mullion cap extensions at the upper view glazing that were replaced with 3-inch caps. Also, "the upper roof overhang had additional louvers that would keep the upper floors on the south side in complete shade; however, those were deleted," Crabtree says. "All in all, the big idea survived, but it was a challenge for the design and construction professionals."
The exterior features an impact-resistant version of the 1600 Wall System 1 curtain wall manufactured by Kawneer Co., Norcross, Ga. Additional framing systems include the Kawneer IR 350 Entrances for the exterior doors, and the Kawneer 350 Medium Stile Entrances with TriFab VersaGlaze 450 framing system for the interior doors and storefront. The systems were finished in a clear anodize. The south elevation curtain wall also features a full span decorative aluminum sunshade.
Armortex, Schertz, Texas, supplied the interior bullet-resistant glazing, Level 3-rated ballistic glass. Virginia Glass Products, Ridgeway, Va., also supplied ½-inch clear tempered glass.
The $38 million project was designed to achieve Silver rating from the U.S. Green Building Council's Leadership in Energy and Environmental Design program. The City of Sarasota, the client, requires all public buildings meet LEED.
Notable non-glazing elements of the structure include a blue steel framework around the roofline, a Z-shaped exposed brace at the entry plaza and rectangular white braces on the west and north facades.
Additional players include metals fabrication company Florida Aluminum & Steel, Ft. Myers, Fla., and general contractor Kraft Construction, Sarasota. The project was completed in June 2010.