The Bullitt Center is the greenest commercial office building in the world. It is a certified Living Building; earning the certification meant demonstrating a full year of meeting net-zero energy and water use. In addition, toxic chemicals were screened from all the building materials and all the wood was certified by the Forest Stewardship Council. Toilet waste is composted and rainwater is captured for all uses, even drinking. The building has a wide solar-paneled overhang and a prominent glass-enclosed staircase gives tenants an appealing alternative to the elevator.