Fresno, CA Accessory Structures: ADU Rules (2026)

Fresno Municipal Code (Citywide Development Code) Section 15-2754 governs Second Dwelling Units, Backyard Cottages, and Accessory Living Quarters. The local code allows one such unit on any lot in any residential district where single-unit dwellings are permitted, sets minimum lot sizes (6,200 sq ft for a Second Dwelling Unit, 6,000 sq ft interior / 5,000 sq ft corner for a Backyard Cottage, 5,000 sq ft for Accessory Living Quarters), caps habitable floor area (1,250 sq ft Second Dwelling Unit, 440 sq ft Backyard Cottage, 500 sq ft or 30 percent of the primary dwelling for Accessory Living Quarters), and limits building height to 30 feet. However, California's state ADU statutes (Government Code Sections 66314 through 66323, formerly 65852.2) preempt many of these standards: a local agency must ministerially approve, without discretionary review, at least one detached new-construction ADU of up to 800 square feet with side and rear setbacks of no more than 4 feet, and must allow heights of 16 feet (detached), 18 feet (near transit or multistory), or up to 25 feet (attached). Minimum-lot-size requirements and owner-occupancy mandates cannot bar a state-qualifying ADU. The City offers five pre-approved standard ADU plans (340 to 1,015 sq ft) to streamline permitting.