Last updated: January 2026 · 4 min read
San Diego ADU / Accessory Dwelling Unit Guide
San Diego homeowners can add an Accessory Dwelling Unit (ADU) to expand property potential and generate rental income. The Development Services Department (DSD) regulates ADU construction, requiring permits for most residential additions over 120 square feet or involving structural changes.
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What Requires a ADU / Accessory Dwelling Unit in San Diego
San Diego allows ADUs on most residential properties with single-family or multi-family zoning. Property owners must meet specific criteria including setback requirements, maximum unit size of 850 square feet, and maintaining owner occupancy in either the primary or accessory dwelling. Structures must comply with San Diego's unique zoning regulations, which permit both attached and detached ADUs on standard residential lots. The Development Services Department mandates comprehensive documentation proving compliance with local building codes, structural safety standards, and neighborhood architectural compatibility.
What Doesn't Require a Permit
Minor interior renovations under 120 square feet typically do not require ADU permits in San Diego. Temporary structures less than 10 feet tall and not connected to utilities can be installed without formal approval. Repairs that do not alter structural integrity or modify existing footprints generally remain exempt from full permitting processes.
ADU / Accessory Dwelling Unit Costs and Fees in San Diego
San Diego ADU project costs involve multiple fee components. Demolition fees start at $205, while school impact fees run $4.08 per square foot. Specific permit costs vary based on project complexity and square footage. Homeowners should budget for plan review, building permits, mechanical permits, and potential utility connection fees. The Development Services Department recommends consulting their office for precise current pricing, as rates adjust annually.
How Long Does ADU / Accessory Dwelling Unit Approval Take
San Diego's Development Services Department typically processes standard ADU permits within 8-12 weeks. Complex projects involving significant structural modifications or unique zoning challenges might extend review periods. Expedited review options exist for straightforward additions meeting all pre-approved criteria, potentially reducing processing time to 4-6 weeks.
Required Documents for San Diego ADU / Accessory Dwelling Unit
San Diego requires comprehensive documentation for ADU permits. Homeowners must submit detailed site plans, architectural drawings, structural calculations, and proof of property ownership. Required documents include scaled floor plans, exterior elevation drawings, energy compliance reports, and neighborhood context illustrations. Digital submissions through DSD Online Services are preferred, with high-resolution PDF files mandatory.
Step-by-Step Application Process
Navigating San Diego's ADU permit process requires strategic preparation and thorough documentation.
- 1
Initial Consultation
Schedule preliminary review with San Diego Development Services Department to confirm project eligibility.
- 2
Documentation Preparation
Compile comprehensive architectural plans, site surveys, and required technical drawings.
- 3
Online Submission
Submit complete application package through DSD Online Services portal.
- 4
Plan Review
DSD reviews submitted documents, potentially requesting additional information or modifications.
- 5
Permit Issuance
Upon approval, receive official ADU construction permit with specific conditions and requirements.
Required Inspections
San Diego mandates multiple inspection stages for ADU projects. Initial site inspections verify existing conditions and proposed work boundaries. Subsequent inspections occur during foundation, framing, electrical, mechanical, and final completion phases. Contractors must schedule each inspection through the Development Services Department, providing 48-hour advance notice.
Tips for Faster Approval in San Diego
Successful ADU permitting in San Diego requires meticulous preparation. Submit complete, high-quality documentation with precise measurements and clear drawings. Anticipate potential questions by including comprehensive context about neighborhood compatibility and structural integration. Ensure energy efficiency compliance and demonstrate alignment with local zoning regulations to expedite review processes.
Frequently asked questions about San Diego adu permits
How much does a ADU / Accessory Dwelling Unit cost in San Diego?
ADU project costs range from $50,000 to $250,000, with school impact fees at $4.08 per square foot and demolition fees starting at $205. Total expenses depend on project complexity, size, and specific site requirements.
How long does it take to get a ADU / Accessory Dwelling Unit in San Diego?
Standard ADU permit processing takes 8-12 weeks. Expedited reviews for straightforward projects can reduce timelines to 4-6 weeks. Complex projects might require longer review periods.
Can I apply for a ADU / Accessory Dwelling Unit online in San Diego?
San Diego's Development Services Department offers full online application through their DSD Online Services portal. Digital submissions with high-resolution PDFs are preferred for faster processing.
Do I need a contractor for a ADU / Accessory Dwelling Unit?
While owner-builder options exist, most San Diego ADU projects require licensed contractors familiar with local building codes. Complex structural modifications strongly recommend professional contractor involvement.
What happens if I build without a permit in San Diego?
Unpermitted ADU construction can result in significant penalties, including stop-work orders, retroactive permit fees, potential fines up to $5,000, and mandatory demolition or reconstruction to meet code requirements.
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Related Permits in San Diego
San Diego Building Department Contact
Development Services Department
1222 First Ave, San Diego, CA 92101