Pittsburg, CA Accessory Structures: ADU Rules (2026)

Accessory Dwelling Unit (ADU) regulation in Pittsburg is largely preempted by California state law under Government Code 65852.2 and 65852.22, as strengthened by AB 68, AB 881, SB 13 (all 2019), AB 3182 (2020), and AB 1033 (2024). The city must ministerially approve at least one ADU and one Junior ADU (JADU) on any lot with an existing or proposed single-family dwelling, and ADUs on multifamily lots proportional to existing unit counts. Cities cannot require setbacks greater than 4 feet on sides and rear for a detached ADU, cannot impose lot coverage or FAR rules that would preclude an 800 sq ft, 16-foot-tall ADU, and cannot require replacement parking when a garage is converted or when the ADU is within half a mile of high-quality transit. Impact fees are prohibited for ADUs under 750 sq ft, and proportional for units 750 sq ft and up. The city must act on a complete ADU application within 60 days. JADUs up to 500 sq ft are allowed within the existing single-family footprint and may share a bathroom with the main house. AB 1033 (2024) allows cities to opt in to ADU condo-ization so owners can sell ADUs separately. Pittsburg has adopted a local ADU ordinance consistent with these mandates; applications go to Community Development with standard plan check, building, and utility permits.