ADU Permit Guide for San Diego, California — Step-by-Step Process (2026)

You must own the property outright or hold clear title to apply for an ADU permit in San Diego. The city requires proof of property ownership through a current title report dated within 90 days of application submission. Your property must contain an existing legal single-family dwelling as the primary residence — you cannot build an ADU on vacant land.

Verify your property's zoning designation first. San Diego allows ADUs in most residential zones, including RM-1-1 and RS-1-7, but each zone has specific requirements. Use the city's online zoning tool /search by entering your address to confirm your property's zone classification. Print this verification page — you'll reference it throughout the permit process.

Obtain a current title report from a title company, which costs $150-$300. This document must show no liens, easements, or restrictions that would prevent ADU construction. Some properties have CC&Rs (Covenants, Conditions & Restrictions) that prohibit secondary dwelling units, even though state law now limits these restrictions.

Several factors automatically disqualify properties from ADU eligibility. Properties with existing unpermitted structures must resolve code violations before ADU application. Properties in coastal overlay zones face additional restrictions. If your home sits on a lot smaller than 5,000 square feet in RS zones, you may only build a junior ADU (JADU) up to 500 square feet.

Properties with active code enforcement cases cannot proceed with ADU permits until violations are resolved. Check your property's code enforcement status through the city's online portal using your address. Outstanding permit violations for unpermitted work must be cleared first, which can add 3-6 months to your timeline.

The city maintains a Property Information Map that shows setbacks, flood zones, and overlay districts. Access this tool /search and print the property report. Properties in historically significant areas require additional design review, extending the process by 4-6 weeks beyond standard timelines.

Start with a detailed property survey to verify exact lot boundaries and existing structure locations. Your ADU must maintain specific setbacks: 4 feet from rear and side property lines for detached ADUs, though some exceptions allow zero setbacks for existing garage conversions. Use San Diego's setback calculator /tools/setback-calculator to determine your exact requirements based on your zone.

Utility capacity analysis prevents costly surprises later. Contact SDG&E to verify electrical service capacity — older homes often need panel upgrades costing $2,000-$5,000. Water and sewer capacity rarely pose problems in developed areas, but properties on private septic systems need percolation tests. Call the city's Development Services Department at (619) 446-5000 to schedule a preliminary utility review.

San Diego offers pre-application meetings for complex ADU projects. These 30-minute consultations cost $402 and typically schedule within 2 weeks of request. Bring your property survey, preliminary design sketches, and the Property Information Map printout. Staff will identify potential issues with setbacks, height limits, or special overlay requirements before you invest in professional plans.

Tree preservation requirements significantly impact ADU placement. San Diego protects all native oak trees and requires permits for removal of trees over 12 inches in diameter. The city arborist must approve any tree removal or significant root disturbance, adding 3-4 weeks to your permit timeline. Survey existing trees and measure trunk diameters at chest height.

Parking requirements are minimal under current state law. You're not required to provide additional parking for your ADU if it's within 0.5 miles of public transit or in a historic district. For other locations, one parking space is required, but it can be covered, uncovered, or even a tandem space behind existing parking.

Fire access requirements affect ADU design and placement. Properties on private roads or those requiring new addresses need fire department review. Corner lots and properties with limited street access face stricter requirements. Review fire access standards in the city's ADU development standards document before finalizing ADU placement.

San Diego requires complete architectural plans including site plan, floor plans, elevations, electrical plan, plumbing plan, and structural calculations. Plans must be drawn to scale and include all dimensions, materials specifications, and construction details. The site plan must show the entire property with existing structures, proposed ADU location, setback dimensions, and parking areas.

Hire a licensed architect or use pre-approved ADU plans to save time and money. San Diego maintains a library of pre-approved ADU designs that expedite the review process by 2-3 weeks. These plans cost $500-$2,000 versus $8,000-$15,000 for custom architectural services. Pre-approved plans still require site-specific modifications for foundation and utility connections.

Energy compliance calculations are mandatory under California's Title 24{:target="_blank"} energy code. Your plans must include detailed insulation specifications, window efficiency ratings, and HVAC sizing calculations. Most architects include this service, but standalone energy consultants charge $800-$1,500 for compliance documentation. The city requires a CF-1R form signed by a certified energy analyst.

Structural plans must be stamped by a California licensed structural engineer for all new construction. Garage conversions may qualify for simplified structural review if no walls are removed. Structural engineering costs range from $1,500-$4,000 depending on ADU size and complexity. Foundation plans must show soil bearing capacity and drainage details.

Plan reviewers focus on specific elements that frequently cause delays. Show all required clearances around windows and doors. Include detailed sections showing roof construction and insulation installation. Label all rooms with square footage and ceiling heights. Show locations of smoke detectors, carbon monoxide detectors, and electrical outlets with specific spacing requirements.

The electrical plan must show panel location, circuit routing, outlet placement, and load calculations. Include exterior outlets, bathroom GFCI protection, and kitchen appliance circuits. Plumbing plans must show fixture locations, pipe routing, and connection points to existing systems. Include gas line routing for water heaters and appliances.

Submit your ADU permit application through San Diego's online Development Services Portal or in-person at the Development Services Center, located at 1222 First Avenue, 2nd Floor. Online submission operates 24/7, while in-person submissions are accepted Monday-Friday, 8:00 AM-4:00 PM. Online applications typically process 2-3 days faster than paper submissions.

Required documents include: completed ADU permit application (Form DS-318), complete architectural plans (4 sets for paper submission, PDF for online), property survey, title report, energy compliance documentation (CF-1R), structural calculations, and geotechnical report if required. Missing documents trigger automatic rejection, restarting your 60-day review clock.

Permit fees range from $5,000-$15,000 based on ADU size and complexity. Basic fees include plan check ($1,200-$3,500), building permit ($2,500-$8,000), and inspection fees ($800-$1,500). Additional fees apply for electrical permits ($200-$600), plumbing permits ($150-$400), and mechanical permits ($150-$300). Pay fees online with credit card or in-person with check.

School impact fees of approximately $4.79 per square foot apply to all ADUs, regardless of size. A 600-square-foot ADU incurs about $2,874 in school fees, payable before permit issuance. These fees are non-negotiable and support local school district infrastructure.

Complete the ADU application form accurately to avoid delays. Common errors include incorrect property descriptions, missing owner signatures, and incomplete contractor information. If using an owner-builder permit, you must complete additional affidavits and provide proof of property ownership. Licensed contractors must include current license numbers and insurance certificates.

The 60-day review period begins only when your application is deemed complete. Incomplete applications receive rejection notices within 5 business days listing required corrections. Resubmit missing items promptly to restart the review clock. Track application status through the online portal using your permit number.

After accepting your complete application, the city assigns your ADU permit to multiple review disciplines: planning, building, fire, public works, and utilities. Each department has 60 days total to complete their review, though most coordination happens simultaneously rather than sequentially.

Planning staff reviews zoning compliance, setbacks, height limits, and design standards. Building plan checkers verify structural adequacy, code compliance, and construction details. Fire department reviews access requirements, water supply, and life safety systems. Public works examines drainage, sidewalk connections, and utility capacity.

Plan check comments arrive via email as PDF documents listing required corrections by discipline. Comments range from minor clarifications like "show window dimensions" to major revisions like "relocate ADU to meet setback requirements." Each comment includes specific code references and required corrections.

Typical plan check comments address missing dimensions, unclear construction details, energy code deficiencies, and structural calculation errors. Planning comments often focus on setback verification and height calculations. Building comments address egress requirements, electrical outlet spacing, and bathroom ventilation. Fire comments involve access routes and water pressure calculations.

Respond to plan check comments with revised drawings addressing each item specifically. Highlight all changes on your plans and provide written responses explaining corrections made. Resubmission fees range from $500-$2,000 depending on the extent of revisions required. Minor corrections may qualify for over-the-counter resubmission.

Most ADU permits require 1-2 rounds of plan check corrections. Complex projects or those with significant code issues may require 3-4 review cycles. Each resubmission adds 2-3 weeks to your timeline. Work closely with your architect or designer to address comments thoroughly in the first revision to minimize delays.

After permit approval, you have 180 days to begin construction and must complete the project within 18 months. Schedule your foundation inspection before pouring concrete by calling (619) 446-5000 or using the online inspection scheduler. Provide 24-hour notice for most inspections, though some require 48-hour advance scheduling.

Required inspections follow construction sequence: foundation inspection before concrete placement, framing inspection after rough framing completion, rough electrical/plumbing/mechanical inspections before insulation installation, insulation inspection before drywall, and final inspection after project completion. Each inspection must pass before proceeding to the next construction phase.

Foundation inspections verify proper excavation depth, rebar placement, and anchor bolt positioning. Inspectors check soil conditions and drainage provisions. Framing inspections examine structural member sizing, connection details, and egress window installation. Rough utility inspections verify proper installation of electrical, plumbing, and HVAC systems.

Failed inspections require corrections before re-inspection. Common foundation failures include inadequate rebar placement and incorrect anchor bolt spacing. Framing failures often involve missing structural connections or improperly sized lumber. Electrical failures typically involve incorrect outlet spacing or missing GFCI protection.

Insulation inspections verify proper installation and R-values matching Title 24{:target="_blank"} calculations. Inspectors check for thermal bridging and air sealing. Drywall inspection occurs after insulation approval but before interior finish work. Final inspection is comprehensive, checking all systems, safety features, and code compliance items.

Schedule inspections strategically to maintain construction momentum. Failed inspections can delay projects by 1-2 weeks while corrections are made and re-inspections scheduled. Prepare for inspections by ensuring work areas are clean, accessible, and properly lit. Have permit documents and approved plans available on-site during all inspections.

Final inspection occurs after all construction completion and before occupancy. The inspector verifies proper installation of smoke detectors, carbon monoxide detectors, electrical outlets, plumbing fixtures, and mechanical systems. All interior and exterior work must be complete, including final grading and landscaping.

Certificate of Occupancy (CO) issuance typically takes 3-5 business days after successful final inspection. The CO authorizes legal occupancy of your ADU and is required before tenant move-in. You cannot advertise for rent or collect deposits without an approved CO.

Address assignment for detached ADUs requires separate application through the city's addressing division. Submit Form DS-40 with a site plan showing ADU location and proposed address. Address assignment takes 2-3 weeks and costs $156. Some ADUs qualify to use the main house address with unit designations (e.g., 123 Main St. Unit B).

Utility hookups and meter installation coordinate with CO approval. Contact SDG&E to schedule electrical meter installation 1-2 weeks before final inspection. Gas and water connections typically use existing service lines. Internet and cable providers require separate scheduling and may need 2-4 weeks for installation.

You can legally rent your ADU immediately after CO issuance. No additional permits or approvals are required for rental activity. However, register your ADU with the county assessor's office to ensure proper tax assessment. Property taxes typically increase by $50-$200 monthly depending on ADU size and value.

Record your completed ADU with the county recorder to update property records and protect your investment. While not legally required, this documentation helps with future property sales and refinancing. The recording process costs $50-$100 and requires a copy of your approved plans and CO.

Setback violations cause 30% of ADU permit delays in San Diego. Many property owners miscalculate distances from property lines or fail to account for easements. Use a licensed surveyor to verify exact property boundaries before design work begins. The city's setback calculator /tools/setback-calculator provides accurate calculations, but field verification prevents costly redesigns.

Incomplete or inadequate plans trigger automatic rejection within the first week of submission. Missing structural calculations, energy compliance documentation, or dimensioning errors halt the review process immediately. Hire experienced ADU architects familiar with San Diego requirements, or use pre-approved plans to minimize plan deficiencies.

Utility capacity issues delay 15% of ADU permits, particularly electrical service upgrades. Older homes with 100-amp electrical panels often require upgrades to 200-amp service costing $3,000-$6,000. Schedule utility consultations early in the design process. SDG&E provides free load calculations to determine upgrade requirements before plan submission.

HOA conflicts create complex legal delays even though state law limits ADU restrictions. Some HOAs maintain architectural review requirements or design standards that extend approval timelines by 4-8 weeks. Submit HOA applications simultaneously with city permits when required. Review your CC&Rs carefully and consult an attorney if HOA restrictions seem excessive.

Historical district designations require additional design review and compliance with historic preservation guidelines. Properties in designated historic areas must maintain architectural compatibility with existing structures. These reviews add 6-8 weeks to standard timelines and often require specialized architects familiar with historic preservation standards.

Fire access problems affect properties on narrow streets or private roads. ADUs must maintain adequate emergency vehicle access, with specific width and turning radius requirements. Properties requiring new driveways or access modifications need public works approval, adding 3-4 weeks to the review process. Consult fire department guidelines /tools/codes/san-diego during initial design phases.

Tree preservation requirements delay projects when protected trees interfere with proposed ADU locations. San Diego protects native oak trees regardless of size and requires permits for any disturbance to trees over 12 inches in diameter. Tree removal or root zone disturbance requires separate permits costing $500-$2,000 and adds 4-6 weeks to approval timelines. Plan ADU placement to avoid protected trees whenever possible.