San Diego Accessory Dwelling Unit ADU Regulations & Zoning

San Diego, California’s second-largest city and a dynamic coastal metropolis, encompasses diverse neighborhoods ranging from urban downtown and historic districts to family-friendly suburbs and beach communities, anchored by iconic attractions like Balboa Park, the San Diego Zoo, a thriving waterfront, and a robust economy driven by biotech, defense, tourism, and innovation. The city offers world-class amenities, excellent universities, cultural festivals, and a Mediterranean climate that supports an active outdoor lifestyle year-round. Major highways including Interstate 5, Interstate 8, Interstate 15, and State Route 163 provide excellent connectivity across the region and to surrounding areas. Residents enjoy unparalleled access to Southern California’s famed beaches, with the beautiful shores of Coronado just across the iconic San Diego-Coronado Bridge. San Diego supports ADU construction through zoning fully aligned with California state law, helping address the regional housing shortage by enabling multigenerational housing, supplemental rental income, or new home construction San Diego projects. Homeowners interested in a San Diego ADU or San Diego Accessory Dwelling Unit benefit from streamlined, practical regulations that promote quality construction in San Diego while preserving neighborhood character and enhancing housing options in this vibrant coastal city.

Key Fact	Details
Jurisdiction	City of San Diego
Properties Eligible	Lots zoned for single-family or multifamily residential uses with an existing or proposed primary dwelling
Max Units on Single-Family Lot	1 ADU + 1 JADU (additional bonus ADUs possible via density bonus program depending on lot size and affordable units)
Max ADU Size	1,200 square feet for attached or detached new construction; no maximum for conversions within existing structures (+150 sq ft allowed for ingress/egress in qualifying cases)
Max JADU Size	500 square feet
Height Limits	Detached ADUs limited to 2 stories on single-dwelling lots; generally 16 feet with reduced setbacks (higher possible to match primary or base zone height up to underlying limits)
Side & Rear Setbacks	Generally 0 feet (no minimum) for structures ≤16 feet outside high fire hazard zones (Fire Code may require more); 4 feet minimum in high/VHFHSZ or for structures >16 feet when abutting residential uses (or base zone minimum, whichever less)
Front Setback	Consistent with underlying base zone standards
Parking Requirement	Generally none required per state and local rules (exemptions for transit proximity, conversions, etc.); limited exceptions in certain Coastal/Beach Impact Areas (1 space unless exempt); no replacement required for most garage conversions
Owner-Occupancy	Not required for standard ADU; required for JADU (owner must reside in primary or JADU)
Rental Rules	Long-term rentals only (minimum 31 consecutive days); short-term rentals prohibited
Permitting	Ministerial approval (Process One) with building permit; targeted 60-day review; Coastal Development Permit required in Coastal Overlay Zone for many projects
Pre-Approved Plans	Yes, available per state law (AB 1332) with 30-day review for qualifying plans
Fire Safety	Full compliance with California Building and Fire Codes; automatic sprinklers required only if mandated for the primary dwelling; defensible space requirements in high fire hazard zones
Official Sources	Information Bulletin 400 and San Diego Municipal Code Chapter 14 Article 1 Division 3

Rent Rates In San Diego

ZIP	CITY	NEIGHBORHOOD	1BR	2BR	3BR	4BR
92101–92145 (multiple ZIPs)	San Diego	Citywide	$2,265	$2,954	$4,872	$6,013

Rentometer — “Average Rent in San Diego, CA” (Data as of 03/19/2026).

San Diego ADU FAQs

1. What are the San Diego ADU regulations and zoning rules for building an Accessory Dwelling Unit?

San Diego ADU regulations align with California state law (Government Code §§ 66310–66342) while incorporating local standards from the San Diego Municipal Code for safety, compatibility, and coastal considerations. The city actively encourages San Diego Accessory Dwelling Unit development to expand housing supply in this diverse coastal metropolis. Compliant ADU San Diego projects receive ministerial approval.

Permitted in residential zones with an existing or proposed primary dwelling
Supports attached, detached, conversion, and bonus configurations in qualifying areas
Coastal Overlay Zone projects must meet additional Local Coastal Program requirements

Official Sources:

https://www.sandiego.gov/development-services/forms-publications/information-bulletins/400

https://docs.sandiego.gov/municode/MuniCodeChapter14/Ch14Art01Division03.pdf

2. How many ADUs can I build on a single-family lot in San Diego?