San Diego region / California
San Diego ADU rules
& permit guide.
San Diego offers custom ADU permits and a path using plans preapproved by specified local agencies. Start by checking whether your parcel is inside the city; unincorporated county projects use a different permitting office.
Editorial review 2026-09-07 · View sources
The local detail to check first
Before you choose a design
The city accepts qualifying plans from San Diego County, Chula Vista and Encinitas. Site design still has to meet San Diego requirements. Bonus ADUs have a separate set of conditions; do not assume a standard backyard project qualifies.
Local requirements at a glance
Min/max ADU size
The city lists a 150 sq ft minimum and a 1,200 sq ft maximum for an ADU. Unit type and applicable development standards still matter.
Setbacks
Front setbacks follow the base zone. Side and rear allowances vary with building height, adjacent residential uses and fire designation; use the city’s setback section for your parcel.
Process
Select the applicable ADU permit path. Preapproved plans still need site-specific review by Development Services.
Your next three steps
- Confirm city jurisdiction, zoning, coastal designation and fire conditions.
- Compare a custom design with accepted preapproved plans; ask who supplies site drawings and utility design.
- Use Development Services’ current ADU/JADU guidance and the applicable information bulletin to prepare your permit submission.
2026 state-law context
ADUs and JADUs have different occupancy rules
California generally prohibits local owner-occupancy requirements for ADUs. A narrow exception applies to certain separately sold affordable ADUs. For JADUs, owner occupancy generally applies when the bathroom is shared with the main home; separate-bathroom JADUs are treated differently under 2026 law. Check the HCD handbook and your project's permit conditions.
Older local summaries may not reflect the latest state changes. Read HCD’s March 2026 handbook, pages 32–33.
A starting point for your design
Local plan resources
Accepted regional preapproved plans ↗
Check which County, Chula Vista or Encinitas plan sets the city currently accepts. Licensing, site work and permit fees remain separate.
Questions for your first planning conversation
- Which approval path applies to my building and ADU type?
- Do easements, trees, slope, access or fire conditions affect placement?
- Which utility upgrades and agency reviews should be included in my budget?
- Are preapproved plans available, and what site work still needs review?