San Antonio architect Jim Poteet, AIA, has long admired shipping-container architecture. But he had never worked with a container himself until a client approached him about transforming one into a guest house for her downtown property. His experience with industrial buildings (including a renovated warehouse where the client lives) gave him and his staff a certain comfort level with the idea. “The way we did the project sums up the way we approach existing buildings,” Poteet says. “We did things that change it in subtle ways and make it work, but didn’t change so much that it loses its identity. It’s still a shipping container.”

The client sourced the blue-painted, Cor-ten steel container herself, while Poteet Architects provided both design and build services. The firm replaced one end of the structure with glass, and carved a large opening for sliding doors into the container’s long side. At night, a deck made of HVAC condenser pads basks in the glow of outdoor light fixtures crafted from painted tractor blades.

For a cooling effect, 4-foot-by-4-foot planters sit a few inches above the container’s roof, with vegetation chosen by landscape architect Jon Ahrens. Icynene insulation also helps keep temperatures down inside the building. Out back, an in-ground tank harvests rainwater to reuse for irrigation. “This was an opportunity to experiment with some sustainable strategies,” Poteet says.