Siegel & Strain has been a leader in sustainable design and historic preservation of buildings in Northern California for over two decades. In addition to authoring "GreenSpec", the widely used industry guide on green materials, the firm has won numerous national awards for ecological design of buildings that respond to climate and decrease energy use and carbon emissions. One current project, the new City of Orinda City Hall, employs natural ventilation, daylighting and careful shading design to eliminate the need for compressor cooling. The building is expected to reduce energy use by over 55%, to reduce carbon emissions by over 50%, and to receive a LEED gold rating.