To create architectural interest in the layout and character of housing fronting streets, variations in setbacks, materials, and design shall be encouraged. Townhome dwellings shall be federal, colonial, traditional, or other style that is compatible with the architecture of the Doylestown, Bucks County area. Cinder block, concrete block, or Tl-11 siding are precluded from use on any exposed exterior wall. Exterior building materials shall be primarily, but not limited to, brick, stone, wood, stone veneer, vinyl siding, or other high quality materials. Decorative cement plaster (stucco) shall be limited to the side and rears of exposed foundations. Architectural renderings shall be submitted at preliminary plan for information purposes only.