Pittsburgh is home to what is arguably one of the greenest buildings in the country: the Center for Sustainable Landscapes, a recently completed facility for research and educational programs on the campus of the 119-year-old Phipps Conservatory and Botanical Gardens. The center, known as the CSL, is aiming for a trio of certifications. In addition to LEED Platinum, the project is one of 150 taking part in the Sustainable Sites Initiative'a pilot program intended to encourage ecologically sensitive landscape-design practices. Phipps and the CSL team hope to achieve four stars, the highest rating possible. But they have even bigger aspirations. They are targeting Living Building status, a designation with tough-to-satisfy requirements such as net-zero-energy and net-zero-water performance.

The $12 million CSL is just the latest piece of a multiphase green expansion program that began after the nonprofit Phipps Conservatory Inc. signed a 100-year lease, taking over management of the city-owned garden in 1993. 'Phipps had the potential to be more successful and become a national tourist attraction,' explains Richard Piacentini, the conservatory's executive director.