The Ridgefield Planning and Zoning Commission has given preliminary approval for a 30-unit, age-restricted affordable housing project.   Charter Group Partners is looking to build on three acres off Danbury Road, near the Senior Center, but also near wetlands.  A formal resolution on approval will be presented to the Commission for a final vote at their meeting on November 7th. Some of the 55-and-older units will be set aside as affordable under the state's 8-30g housing law, though the plans do conform to regulations for building height and setback distances.  The only exception is to density zoning regulations.