Can I Build ADU in San Diego, CA? (2026)
Find out if you can build a adu in San Diego, CA. Rules, permit requirements, costs, and next steps.
Yes, ADUs are allowed in San Diego, CA. California state law ensures by-right approval.
An Accessory Dwelling Unit (ADU) is a secondary housing unit on a residential lot — also called a granny flat, in-law suite, or backyard cottage. In San Diego, CA, ADUs are permitted by right under state law, making them one of the most accessible ways to add housing on your property. ADUs can be detached, attached to the main home, or created by converting an existing garage or accessory structure.
ADU Rules in San Diego
ADU Rules in San Diego: Detached ADU max size: 1200 sq ft. Attached ADU max size: 50% of primary dwelling up to 1200 sqft. Junior ADU (JADU): up to 500 sq ft, within existing structure. Setbacks: 4 ft side, 4 ft rear. Owner-occupancy: Owner-occupancy requirement eliminated statewide effective January 1, 2020 per AB 68. No owner-occupancy required for primary dwelling or ADU.. State preemption applies: CA law requires San Diego to approve compliant ADUs by right.
Costs & Fees
ADU permits in San Diego: Total estimated permit cost: $2,500–$9,000 total permit fees depending on size and scope. Contact the San Diego Development Services Department (DSD) for current fee schedule.
Timeline
Ministerial approval within 60 days per Gov Code 65852.2(a)(3). San Diego Development Services Department (DSD) ADU permit typically 3-6 weeks for plan check. Standard plan program available at: https://www.sandiego.gov/development-services/news-programs-and-resources/programs/adu
Next Steps
Next steps for building an ADU in San Diego: 1. Review full ADU rules including size limits, setbacks, and parking. 2. Apply for an ADU permit through the San Diego Development Services Department (DSD) at https://www.sandiego.gov/development-services/opendsd. 3. Hire a licensed contractor familiar with CA ADU requirements.
San Diego Development Services Department (DSD)
Phone: (619) 446-5000
Website: https://www.sandiego.gov/development-services
Online Permits: https://www.sandiego.gov/development-services/opendsd
Frequently Asked Questions
Can I build an ADU in my backyard in San Diego?
Yes. California state law requires San Diego to permit ADUs by-right on all residential lots. You can build a detached ADU up to 1,200 sqft, plus a Junior ADU (JADU) up to 500 sqft within your existing home. No owner-occupancy requirement applies. San Diego also offers a Standard ADU Plan Program to speed up permit approval. Permits are processed within 60 days.
What are San Diego's Airbnb (short-term rental) rules?
San Diego requires a Short-Term Residential Occupancy (STRO) license ($150/year) for all rentals under one month. There are four license tiers: Home-Sharing (hosted), Whole-Home Primary Residence, Mission Beach properties, and Whole-Home Non-Primary Residence (limited citywide via lottery). The 10.5% Transient Occupancy Tax applies to all short-term rentals. Operating without a license carries fines of $1,000 per day.
How does San Diego's zoning system work?
San Diego uses the Land Development Code (LDC) with community plan areas governing local land use. Residential zones use a numeric system — RS (Residential Single Unit) or RM (Residential Multiple Unit) followed by numbers indicating density (e.g., RS-1-4 = single-unit residential, 4,000 sqft minimum lot). Each of San Diego's 107+ communities has its own community plan that implements the General Plan for local conditions.
Do I need a permit to run a business from my home in San Diego?
Yes. A Home Occupation Permit ($175) is required for any business operated from a residence. Restrictions: no clients on-site, no non-resident employees, no exterior signs, maximum 25% of floor area used for business. San Diego's LDC Section 113.0295 governs home occupations.
What are the setback requirements for a single-family home in San Diego?
Setbacks in San Diego vary by zone designation. In the most common RS-1-4 (single-family residential) zone: front yard 15 ft, side yards 4 ft, rear yard 15 ft. Larger lot zones (RS-1-7, RS-1-14) have proportionally larger setbacks. Canyon-adjacent properties often have additional open space easements limiting building closer to canyon edges.
Are solar panels required on new homes in San Diego?
Yes. California's Title 24 Energy Code requires solar PV on all new low-rise residential construction. San Diego receives 266+ sunny days per year — one of the best solar markets in the US. SDG&E net metering is available. Properties in San Diego's Coastal Zone may need additional Coastal Commission review for rooftop modifications, but solar cannot be denied for code-compliant installations.
What is San Diego's Coastal Zone and how does it affect my property?
San Diego's Coastal Zone encompasses roughly the westernmost 3-4 miles of the city, covering neighborhoods like Ocean Beach, Mission Beach, Pacific Beach, La Jolla, and others. Properties in the Coastal Zone require a Coastal Development Permit (CDP) from the California Coastal Commission for new construction, additions over 10% of existing floor area, and some changes to primary structures. This applies in addition to regular city building permits and can add 2-6 months to project timelines.
Source: San Diego Development Services Department (DSD) — Building Regulations. Last verified April 5, 2026. View source