Pioneer of sustainable architecture Sim Van der Ryn talks to CNN about his work . Hide Caption 1 of 10 Photos:Photos: The future of cities in the US Former Chief Architect for California worried that LEED regulations are n't enough .
Pioneer of sustainable architecture Sim Van der Ryn talks to CNN about his work . The Bateson Building in Sacramento still regarded as an a icon of ecological design . Former Chief Architect for California worried that LEED regulations are n't enough .