In addition to housing, office and retail space, the proposals from the three firms vying to guide the transformation of the Concord Naval Weapons Station to civilian use include a vast "Central Park," a solar panel farm, orchards and community gardens. Adopted in 2012, the Concord Reuse Project Area Plan calls for building up to 12,272 housing units and 6.1 million square feet of commercial space on about 2,300 acres near the North Concord/Martinez BART station -- rolling land now dotted with rusty rail tracks and old storage bunkers.