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Among the more than 150 projects participating in the SITES pilot is the Center for Sustainable Landscapes (CSL) at the Phipps Conservatory and Botanical Gardens in Pittsburgh. The recently completed building, which houses the 119-year-old public garden’s educational and research programs and administrative offices, is seeking the highest level of SITES certification—four stars. In addition, the $14.5 million project is targeting a LEED Platinum rating as well as “Living Building” status. The latter designation is widely regarded as one of the toughest green building certifications to achieve.

In order to satisfy the requirements of this rating system trifecta, the design team developed a “synthetic solution” in which the 24,000-square-foot CSL and the surrounding 2.65-acre site work as one, explains Chris Minnerly, principal of Pittsburgh-based The Design Alliance, the project’s architect. The building steps down with its steeply sloping site, has its long axis oriented east-west to minimize solar gain and a thermally robust exterior envelope with a skin of wood reclaimed from dismantled Pennsylvania barns. It will generate all of its own energy with photovoltaic panels, a vertical axis wind turbine, and geothermal wells.

The landscape is still in the process of being installed, but once complete later this summer, it will include water features, native plant materials, and rain gardens. The scheme will do more than merely look good, says José Almiñana, a principal at Philadelphia-based Andropogon, the project’s landscape architect. “It will perform.”

One of the roles the landscape will play is helping the CSL satisfy all of its water needs (except for drinking water and a few other uses) without relying on external sources other than rainwater. The building and its environs will manage stormwater and treat wastewater. It will put these sources to use for toilet flushing and to offset the significant irrigation demands of the conservatory’s greenhouses.

Phipps’s collection of orchids, for example, will be watered with graywater (water generated by the CSL’s lavatories) and blackwater (water from toilet flushing), but only after the effluent is cleansed in a number of on-site treatment steps that include a traditional septic system and a constructed wetland containing plants such as cattails and rushes chosen for their ability to strip the water of nutrients. A solar distillation system will provide the final purification step.

A separate set of systems will collect rainwater from the CSL’s green roof and the roofs of neighboring buildings, directing it to a lagoon where hydrophytes (plants that thrive when submerged in water) will help remove the small amount of impurities found in roof runoff. After UV treatment, the water will be allowed to infiltrate into the ground or will be stored in cisterns for various non-potable uses on site.