Surplus Equation - The design of a 15-acre sustainable community restores 98% of unique marsh and black oak woodland ecosystem on the edge of the Petaluma River. 28 Units of Senior housing are nestled into the existing topography among and extensive food forest and multiple communal pocket parks. Passive Design, Solar Energy and responsible water management combine to create a surplus of food, and natural resources. The restored land is dedicated to the community as a permanent educational and recreational amenity.