The setback rules do NOT relate to domesticated foul (chicken and other poultry). Here's the code section 20.40.240 "E. Birds (other than domestic fowl) shall be kept in an aviary or loft that meets the following standards: 1. The aviary or loft shall provide one-half cubic foot for each parakeet, canary or similarly sized birds, one cubic foot for each pigeon, small parrot or similarly sized bird, and two cubic feet for each large parrot, macaw or similarly sized bird. 2. Aviaries or lofts shall not exceed 2,000 square feet in footprint. 3. The aviary is set back at least 10 feet from any property line, and 20 feet from any neighboring dwelling unit." This code does NOT pertain to chickens. Section D has no restrictions on chickens.