When the leadership team at Ransom Everglades School decided to add a campus building focused on science, technology, engineering, and math (STEM), they wanted to be sure the 45,000 ft2 structure would be as innovative as the learning they would offer within it. The designers took their inspiration from campuses built by tech giants like Google and Apple.
“The building is a pavilion nestled in an interesting place,” says Pat Bosch design director and founding partner for Perkins + Will. The nature-based design was inspired by the trees, wind, and ocean that make up the local environment.
The new building includes 10 classrooms, 11 laboratories, a center of excellence in teaching and learning, faculty areas, and a reconfigurable multipurpose room to host lectures, exhibitions, art installations, and robotic competitions. Designers saw precast concrete as the ideal modern material to cast this innovative educational setting. “Precast concrete was chosen because the owner and designer wanted to create a responsible building that is as intelligent as the students, the activities, and the faculty it will house,” Bosch says.
The building is located in one of the most vulnerable areas of the coastal city. The designers also recognized that precast concrete’s strength and resilience would help them meet strict building codes.
The precast concrete producer and designer worked together to create a lightweight building envelope that not only reflects the core mission statement of school but also meets rigorous standards through the use of forward-thinking construction prefabrication methods. “This precaster offered a responsible system from a carbon footprint, from a manufacturing perspective, from a tectonic point of view, and in the sense of using less material,” Bosch says.
Lightweight but formidable
One of the primary design challenges was addressing facade dead loads, which were only allowed on the roof level to meet the budget for the building structure. In response, the engineer of record designed the building using a post-tension system to reduce slab thickness and eliminate the heavy edge perimeter beams.
The final design includes lightweight architectural precast concrete panels with a composite tube steel engineered framing system featuring a 2- to 2.5-in. mesh reinforced concrete skin. To balance the overall weight and the stiffness of the panels, finite element analysis was used to understand the engineering performance of this system on serviceability, handling, shipping, and fabrication.
Anchors pins embedded in the concrete skin transfer the weight back to the frame, and the frame is connected to the building structure at discrete points. The frame was rigidly designed, but the pin provides enough flexibility to allow concrete skin to breathe.
The resulting design provides 38 lb/ft2, which meets or exceeds the stringent engineering requirements while still delivering the aesthetic appeal desired by the owner. The solution tremendously accelerated the construction schedule to close in the building, saving eight weeks of construction time. The precast concrete facade also serves as a rain barrier and was designed to withstand the hurricane winds and missile impact testing—both of which are required by South Florida building codes.
The stark white facade incorporates vertical openings or “eyelids” to the bay to ensure the building will always draw in the light without creating excessive glare. “The view gives the students peekaboo moments of looking at the bay, while the precast concrete becomes a protected armor to the recessed window,” Bosch says.
The resulting facade delivers a sculptural essence with a delicate form that gives students and faculty a sense movement as they traverse the building.