All districts
UDC Section 6.05.010 sets citywide accessory structure standards: an accessory structure must meet the dimensional standards of the base zoning district, must be on a lot with a principal structure (unless two adjacent lots share common ownership), and its footprint cannot exceed 25 percent of the principal structure's square footage (up to 600 sq ft is allowed for a detached two-car garage even if that exceeds 25 percent, and attached-garage square footage is excluded from the principal-structure calculation used for that test). Structures 8 ft or less in height may sit in the rear-yard setback to within 3 ft of the property line but not in a P.U.E. No more than 30 percent of the rear yard may be covered by accessory structures (up to 50 percent for a detached two-car garage not exceeding 600 sq ft), and all impervious cover limits in Section 11.02 still apply. Confirm plat notes, easements, and overlay status (the Old Town Overlay allows a Certificate of Appropriateness setback exception under Section 3.13) with the Planning Department before acting.