National City ADU Regulations

• ✓Dedicated Planning page with ADU/JADU definitions tied to municipal code sections
• ✓City ADU Handbook is the canonical local reference
• ✓JADU size band 150–500 sq ft described directly on the official page
• ✓Granny flats / ADUs generally discussed for single-family zones in city FAQs

JADU 150–500 sq ft per city materials. ADU standards live in Municipal Code §18.30.380.

State guarantee: California requires every city to allow at least an 800 sq ft ADU exempt from local lot coverage, FAR, and front-setback rules.

Height baseline: 16 ft for detached, rising to 18 ft within ½ mile of major transit. Attached ADUs follow the primary home, capped at 25 ft.

Parking per adopted zoning and division counter guidance. The Planning Counter provides parcel-specific determinations.

Planning Division processes ADU applications. The Planning Counter is open Monday through Thursday, 7 a.m. to 6 p.m.

State backstop: A complete ADU permit must receive a decision in 60 business days. If the city stalls past 30 business days, AB 253 lets you hire a certified private plan checker to force a 10-business-day decision.

Fee and impact details live in the city ADU Handbook and the fee schedule referenced on Planning pages.

SB 543: No impact fees on ADUs ≤750 sq ft. Above 750 sq ft, fees scale to the ratio of ADU size vs the main home.

Visit the official National City ADU page (link in hero) for current eligibility and downloads.

Standard ADUs in National City: no owner-occupancy required (made permanent in 2023).

JADUs: limited to 500 sq ft of interior livable space within an existing single-family home. Owner occupancy is required only when sanitation facilities are shared with the main house. JADUs cannot be used as short-term rentals (AB 1154 / SB 543).