Better with Age

06/13/2016

Historical renovation projects require that glass and glazing companies perform a delicate balancing act between performance and original design aesthetic. Replacement products must seamlessly match the look of existing windows, while meeting today’s building codes. The task becomes even more challenging when impact requirements also play a role. “In any historic project, you’re working with original construction that does not meet the building codes we have today,” says Justin Burkhart, project manager for glazing contractor Key Glass LLC. “You have to find a product that can replace the existing historical products and meet the updated requirements.” Such was the case for the historical window replacement and renovation of the Sarasota Museum of Art, a division of Ringling College of Art and Design. The 57,000-square-foot building was constructed in 1926 as Sarasota High School, and was added to the National Register of Historic Places in 1984. The Collegiate-Gothic style school operated for 70 years, closing in 1996, according to Ringling. About ten years ago, SMOA and Ringling teamed up to convert the historic school building into a contemporary art museum. The complete historical renovation and update of the 90-year-old building included replacement of all of the former school’s windows. “This building is a historical presence in our area. When Ringling bought the school, they wanted to take a project with historical significance and bring the exterior façade up-to-date to meet performance and hurricane-impact requirements,” says Burkhart. The existing wood windows were already replacements for the originals. However, due to years of neglect and periodic repairs, those windows could not be kept. The Key Glass team began by pulling out the existing wood window frames and dissecting them to find the most similar aluminum window system that would meet codes. “We looked at the wood windows—their profiles and shapes—and we took those wood windows apart. We needed to give them a window that resembled what they currently had, and finding shapes and profiles that mimicked what was in place was challenging,” Burkhart says. Key Glass worked closely with window supplier YKK AP throughout the process. In the end, the team used YKK’s YOW 225 TUH thermally broken window system, with insulating, laminated low-E units from Oldcastle BuildingEnvelope. The 2 ¼-inch deep windows meet Florida Product Approval for high velocity hurricane zones. “We tested the 2 ¼-inch window recently [for impact testing] in sizes up to 4 feet by 8 feet. Those sizes fit what was required for this project,” describes Gary Flemming, business manager, commercial window products for YKK AP. “It was then a matter of how to handle where the customer wants the dimension grids.” YKK AP modified the YOW system with trim, muntins and other details to create the historic appearance. The windows feature an enhanced perimeter glazing leg and simulated divided lites, with a grid on top of the glass on the interior and exterior that is structurally glazed to the glass with tape from 3M. The fixed window systems also feature a simulated check rail that creates the appearance of the existing hung window. “It looks like the original hung window style from the street,” Flemming says. YKK also produced a projected window at the top to serve as an air vent. “This included a special sill—an architectural feature that the designer wanted,” Flemming says. Once the system was chosen, the team was faced with the challenge of incorporating the windows into the existing structure. “For any historic project, you have to figure out the means and methods to bridge the surrounding structure,” Burkhart says. This is particularly true in renovation projects in high wind load areas. “In many cases, you have to modify the existing structure—whether that means adding additional steel or finding other solutions. You have to find a solution to allow you to secure the system you’re using to meet the wind load requirements,” he says. For the SMOA project, Key Glass relied on a high-strength epoxy product placed on the window sill to serve as an attachment point for the fasteners. Once installed, the team used onsite testing to verify the performance of the systems in the actual openings. The SMOA project was led by Lawson Group Architects Inc., lawsongroup.net, and by general contractor Willis A. Smith Construction.