The purpose and intent of the Residential Duplex District is to provide for a higher intensity residential area that is a mixture of duplexes with single family dwellings. The purpose is to promote and encourage insofar as is compatible with the higher intensity of residential use, a suitable environment for family life composed in large part of an adult population. Primary considerations are to stabilize and protect the residential area and to control overcrowding of the land. Uses of a commercial nature or appearance are excluded. Maximum residential density is ten dwellings per net acre.