The Thoreau Center for Sustainability, located in the rehabilitated historic wards of the Letterman General Hospital, is the first public/private partnership project completed at the new Presidio National Park. The 73,000 ft2 (6,800 m2) complex is the new home for nonprofit organizations focused on environmental sustainable development issues. This design addresses sustainable development within the constraints of a historic landmark structure.
The most important environmental goal for this project was to prove that it is possible and economically viable to transform and recycle existing historic building resources into new uses for the next century. Historic rehabilitation is a fundamental act of sustainable development.