Reducing energy consumption has long been a focus of the sustainability movement. But another resource is quickly gaining center stage: water. According to the World Health Organization and UNICEF, approximately one in eight people lack access to safe drinking water. In the United States, the building industry alone consumes 12 percent of all water withdrawals, and another 49 percent of water is used to create energy to power the built environment, according to the U.S. Geological Survey. In the face of such overwhelming evidence, the Center for Architecture Science and Ecology—a partnership between Skidmore, Owings & Merrill and Rensselaer Polytechnic Institute—developed a prototype that conserves energy and uses solar energy to passively filter graywater. And the system isn’t stashed in the basement or hidden from view. Instead it takes the unexpected form of a glass façade.

The Solar Enclosure for Water Reuse (SEWR), consists of a series of stacked, cast-glass blocks with carefully calculated profiles. Each block features a standard flat lite on the interior surface, followed by a stiffening frame. The external lite has solar concentrators and graywater flow channels embedded in a surface that is tilted to capture the maximum amount of solar energy. Graywater is directed from indoor faucets (such as faucets, baths, washing machines, and even toilets) and runs through an initial screening and sedimentation process to remove contaminants. The treated water flows through the channels in the SEWR façade system and is heated by the sun. The water is then directed back into the building for another round of treatment before being directed back into household systems. The jury was impressed by the level of SEWR’s integration into the building systems. “It uses the active aspect of the environment and the existing moisture to make a dynamic system,” juror Sylvia Smith says.

By keeping water treatment on site and limiting the amount of freshwater drawn from centralized grids, the system saves energy right out of the gate. And a fortunate side effect of running the water though the glass façade for treatment is that the water itself creates a barrier against heat gain. The façade allows diffuse daylight into the interior, but limits the energy needed to cool the structure. “It has a kind of internal logic to it,” juror William Massie says. “It’s one of those ideas where thickening of the edge of the building is really able to do something.”

Project Credits

Project Solar Enclosure for Water Reuse
Collaborating Institutions Center for Architecture Science and Ecology (CASE), New York; Rensselaer Polytechnic Institute, Troy, N.Y.—Anna Dyson (director, CASE); Jason Vollen (associate director, CASE); Matt Gindlesparger, Kristin Malone, Peter Stark (researchers, CASE); Satoshi Kiyono (research assistant, CASE)