Originally published by The Architects Newspaper
By John Stoughton
The Children’s Hospital of San Antonio is wrapping up an ambitious four-year $135-million renovation project to transform an existing downtown hospital campus into a fully dedicated, freestanding children’s hospital. The facility remained open throughout an intensive construction process involving interior demolition, relocating care units, exterior shell upgrades, and energy efficiency upgrades. A recladding concept, which extends the interior rebranding to the facade, is the most visible component of the project. The color palette is derived from a local artist’s mural on the existing structure became the basis for a rebranding strategy that seeks to improve visitor’s experience of the campus by benefitting the healing process and improving wayfinding. Colors are distributed onto the facade through a series of custom unitized channel glass assemblies that were the result of a close collaboration between Overland Partners, Bendheim Wall Systems, and Sharp Glass.
The existing structure consists of five-foot concrete wings that extend out from the building envelope. With restrictive load limits and limited space for installation and maintenance, the design needed to be lightweight and convenient to assemble. Also, the team required a solution that could be manufactured in a range of custom colors, visible at long distances day and night.
The project team developed a unitized modular strategy to consolidate three channel glass shapes into an extruded framework. Bendheim modified one of its existing systems to allow the glazer to preassemble the units in its shop so that the glass was bonded to both a head and sill extrusion. To ensure individual glass pieces did not make contact, the channels were set with a quarter-inch gap filled with a silicone backer rod and sealed with a translucent silicone. These units were harnessed together with a removable frame system developed by Bendheim in close collaboration with the architect and the glass installer. This allowed the units to be brought from the shop to the hospital, then strapped and hoisted into place by a three-person crew on each floor who would swing the unit into place.
Units were lifted up into a pre-mounted head receptor and loaded onto an “elevator platform” that could be adjusted vertically to accommodate tolerance and deflection in the existing construction. This detail allows for movement over time without putting the glass units at risk. The adjustable, unitized system allowed the glazer to install, on average, an entire floor per day.
Kris Feldmann, lead architect at Overland Partners, said that the value engineering presented a design management challenge to the project: “We saw the channel glass feature as something that was just as critical to the rebranding of the hospital and the work they were doing on the interior. One of the challenges of any project like this is that it is a very easy thing to remove as project budgets evolve. Having the owner’s confidence—because we had worked closely with the contractor, sub-contractor, and Bendheim—was really critical to keeping it on the project.”
The quarter-inch channel glass includes a ceramic frit that produces a unique translucent finish, allowing for sunlight penetration and providing a soft glow to patient rooms. At night, integrated programmable LED lights provide accent lighting for the facade. Several full-size panels were produced in a mock up to allow the team to confirm desired lighting details prior to construction.
The units appear to be the same height from the exterior, but field-verified dimensions confirmed each floor height varied by several inches. This required every unit to be individually measured and coded by Bendheim to confirm a custom fit, and accurate color as specified by the architect.
Beyond this colorful additive layer, most of the existing facade remained in place. The exterior shell includes replacement insulated glazing units and an interlocking metal panel exterior wall finish. Replacement windows consist of interior glazed window units to avoid having to re-scaffold the entire building as floors became open for construction.
While the exterior is substantially complete, some components of the project remain under construction, including exterior gardens that feature culinary, play, and prayer programming.
The original story can be found here.