Homeowner Advice

What is San Diego’s ADU permitting process?

September 30, 2025

29 min read

San Diego’s ADU permitting process is the official city review that approves the design, safety, and code compliance of Accessory Dwelling Units (ADUs) before construction. It matters now more than ever because ADUs have become a major piece of California’s housing supply, with nearly 20% of all new homes in San Diego by 2024 built as ADUs (UCSD CHPD). Statewide, ADU growth has been explosive—permits surged by 15,334% between 2016 and 2022, totaling over 83,865 units (CA YIMBY). While ADUs open doors for extra income and housing flexibility, many homeowners say the process can feel overwhelming—like “going to court without a lawyer” (Casita Coalition).

Aerial view of residential neighborhood in San Diego showing ADU housing additions – What is San Diego’s ADU permitting process.

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Korey Turk is a designer with over 15 years of construction experience, creating ADUs that enhance property value and fit naturally with the home, bringing clients' visions to life.

What Is the San Diego ADU Permitting Process?

San Diego’s ADU permitting process is the official city review that ensures your Accessory Dwelling Unit (ADU) meets local zoning, building codes, and state housing laws before construction can begin. The process typically includes submitting architectural plans, completing required forms, paying applicable fees, and undergoing plan review and inspections through the City’s Development Services Department. This step-by-step approval ensures your project is safe, compliant, and eligible for final occupancy once built (City of San Diego – ADU Guide).

“Actually, it doesn’t really matter what you call it. What you get is more housing.” — Denise Pinkston, Casita Coalition (CalMatters), paraphrasing Shakespeare’s famous line, “What’s in a name?”

Framing of an ADU under construction – What Is the San Diego ADU Permitting Process.

Submitting complete ADU architectural plans upfront streamlines plan check and avoids delays in the City’s Development Services review.

Why Build an ADU in San Diego?

Building an Accessory Dwelling Unit (ADU), often called a granny flat or Junior ADU, in San Diego is one of the most effective ways to create affordable housing while also benefiting homeowners. An ADU can generate steady rental income, increase property value, and provide flexible space for family members. As part of California’s efforts to address the housing affordability crisis, ADUs have become a cornerstone of local infill developments, supported by both California state law and the City of San Diego Development Services Department.

Research from UC Berkeley’s Terner Center shows that the median rental price of a new ADU is around $2,000 per month, while locally, returns can be even stronger—for example, a one-bedroom ADU in North Park rents for about $2,400. With supportive zoning regulations, reduced setback requirements, and programs like San Diego’s ADU Bonus Program, homeowners are finding ADUs to be a practical way to add living space and meet community housing affordability goals.

Aerial photo of a backyard ADU beside a pool in San Diego – Why Build an ADU in San Diego.

ADUs in San Diego generate strong rental income potential, with units in neighborhoods like North Park renting above $2,400 per month.

Step-by-Step Guide: How to Get an ADU Permit

In San Diego, most ADU permit applications follow a five-step path: confirm zoning regulations, prepare your plans, submit online, complete the plan check process, and then move forward with permit approval and inspections. Typical timelines run 3–5 months, though in past years the average processing time was closer to 217 days (~7 months), which shows why accurate submittals and fast responses matter.

Understanding setback regulations, parking requirements, and other local zoning standards up front helps prevent costly delays. Homeowners should also be aware of permit costs like the Application Fee, Plan Check Fee, and potential Development Impact Fees, which vary depending on project size. A complete and compliant package gives the City of San Diego Development Services Department everything they need to keep your review on track.

5 Steps to Getting an ADU Permit in San Diego

Check Zoning & Requirements
Review Information Bulletin 400 to confirm your property qualifies and to understand lot coverage, setback regulations, and off-street parking standards.
Prepare Site & Floor Plans
Assemble a full set of ADU architectural plans: site plan, floor plans, elevations, structural calculations (if required), and Title 24 energy compliance documents.
Submit Online Application
File your ADU application through the City’s Planning & Development Services portal. Pay any initial permit fees and ensure your Permit Application Form is complete.
Plan Review & Corrections
City reviewers check your submittal against the California Building Standards Code and the local Municipal Code. Respond quickly to any correction notices—delays usually happen at this stage.
Permit Approval & Inspections
Once approved, permits are issued and construction can begin. You’ll need to pass required inspections (such as framing, electrical, and final sign-off) before your ADU can be legally occupied.

Workers applying stucco to an ADU exterior – Step-by-Step Guide: How to Get an ADU Permit.

Passing inspections, from framing to final finishes, ensures your ADU is fully compliant and ready for occupancy.

Key Regulations to Know (2025 Updates)

In San Diego, homeowners can build an Accessory Dwelling Unit (ADU) without a minimum lot size requirement. Detached or attached ADUs may be up to 1,200 square feet, with side and rear setback regulations of at least four feet. Parking rules are often waived in Transit Priority Areas, but when required, each ADU must provide one off-street parking space. New 2025 updates to the Zoning Ordinance introduced limits on multiple ADUs in single-family residential zones, a two-story maximum height, and restrictions on building in high-fire cul-de-sacs. These updates align with both California State ADU Guidelines and the California Building Standards Code, ensuring safety while balancing neighborhood character.

San Diego 2025 ADU Rules at a Glance

Lot size: No minimum required.
Maximum size: Up to 1,200 sq ft for detached or attached ADUs.
Setbacks: At least 4 feet from side and rear property lines.
Parking: One off-street space required unless waived (e.g., within ½ mile of public transit or if converting an existing garage).

New restrictions (2025 updates):

Cap on multi-ADUs in single-family neighborhoods (KPBS).
Two-story height limit for most neighborhoods (ADU Geeks).
No ADUs allowed on high-fire cul-de-sacs (KPBS).

“The people who live here, who have lived here for decades, are not against housing but they are against speculative development that undermines public safety and livability.” — Jennifer Campbell, Councilmember (ADU Geeks)

Before vs. After: San Diego ADU Regulations

Regulation Area	Before 2025	After 2025 Updates
Lot Size	No minimum required	No change
Maximum ADU Size	Up to 1,200 sq ft	No change
Setbacks	4 ft side/rear	No change
Parking	Waived near transit; otherwise 1 space	No change
Multi-ADUs	Bonus ADUs allowed in many zones	Capped in single-family zones
Height Limit	Allowed above 2 stories in some cases	2-story height limit
High-Fire Areas	ADUs allowed with conditions	Prohibited on cul-de-sacs in high-fire zones

What Do San Diego ADU Permits Cost?

In San Diego, most homeowners spend between $6,500 and $21,000 on city-related ADU permit fees, which generally include the application fee, plan check fee, and utility connections. These fees are only a portion of the overall budget, as the median statewide construction cost of an ADU is about $150,000—roughly $250 per square foot—according to the Terner Center. Exact permit costs vary depending on your project’s size, whether the unit is under 750 sq. ft. (qualifying for certain ADU permit fee waivers), and site-specific utilities connections such as water, sewer, or SDG&E interconnection. For some projects, additional items like fire sprinklers or compliance with the California Building Standards Code can also impact costs.

Key Takeaway for Homeowners

Budget $6k–$20k for permit-related city fees, then account for construction as the largest expense. Smaller ADUs under 750 sq. ft., especially those located in Transit Priority Areas, may qualify for reduced or waived impact fees, while larger detached units may trigger higher Development Impact Fees. Regardless of size, the majority of overall cost comes from construction—averaging $150,000 statewide—with final numbers influenced by factors like site work, zoning limits, and the type of ADU (detached, attached, or Junior Accessory Dwelling Unit).

Common ADU Permit-Related Fees in San Diego

Fee Type	What It Covers
Application / Intake Fee	Sets up your project in the City’s system before formal review.
Plan Review Fee	Pays for technical review of your plans against building and zoning codes.
Building Permit Fee	Covers the cost of issuing permits that authorize construction to begin.
Impact Fees	Typically waived for ADUs ≤750 sq. ft.; larger units may trigger scaled fees.
Utility / Connection Fees	Costs for water, sewer, and electric service connections (varies by lot).

How to Breeze Through the Process

The fastest way to secure your ADU permit in County of San Diego is to use pre-approved plans, work with an experienced licensed contractor or ADU Consultant, and submit a complete, code-compliant package from day one. Quick responses to City review comments are critical, and you should be ready for added steps if your property falls within the California Coastal Commission’s Coastal Overlay Zone or other special areas. Knowing how the Zoning Ordinance and construction standards apply to your site can help you avoid delays and unexpected costs.

Pro Tips for a Smooth ADU Permit Approval

Use Pre-Approved ADU Plans
San Diego accepts permit-ready designs that can shorten review times to about 30 days, saving weeks of corrections and resubmittals.
Work With Experienced ADU Pros
Homeowners often describe the permitting process as feeling like “going to court without a lawyer”—a phrase highlighted by the Casita Coalition. Partnering with a local team like Better Place Design & Build, which specializes in ADUs, avoids delays and ensures compliance with the California Building Standards Code and city requirements.
Submit a Complete Application Upfront
Provide all required documents—site plan, floor plans, Title 24 energy reports, and structural details—when you file your application. Missing items or incomplete packages are one of the top causes of delays and added permit check fees.
Be Proactive With Corrections
If reviewers request clarifications, reply within days. Timely responses can prevent extended hold-ups and keep your permit moving forward.
Watch for Special Zones
Properties in areas like High Fire Hazard Zones or the Coastal Zone may require additional permits or reviews. Check Information Bulletin 400 early so you understand setback regulations, parking requirements, and subdivision mapping rules that may apply.

Contractor reviewing ADU permit plans outdoors – How to Breeze Through the Process.

Always work with an experienced ADU consultant or licensed contractor—expert guidance keeps your submittals compliant and avoids costly resubmittals.

Resources for Homeowners

Navigating the ADU permit process in San Diego doesn’t have to feel overwhelming. These trusted resources provide clear guidance on zoning regulations, setback requirements, parking standards, and construction standards—everything a homeowner should review before starting their project.

City of San Diego – Information Bulletin 400 (ADUs & JADUs)
The City’s official guide covering Accessory Dwelling Units (ADUs) and Junior Accessory Dwelling Units (JADUs), including size limits, lot coverage, parking requirements, and step-by-step permitting details.
👉 Read Information Bulletin 400
California Department of Housing & Community Development (HCD) – ADU Handbook
A statewide resource explaining California State ADU Guidelines, homeowner rights, and best practices. It’s the definitive source for understanding how California state legislature reforms like Senate Bill 1069 and AB 671 protect your right to build.
👉 Download the HCD ADU Handbook
Casita Coalition – ADU Equity & Policy Insights
A nonprofit dedicated to ADU policy and technical assistance, with research on barriers such as financing, owner occupancy, and unpermitted ADUs that some homeowners face in the permitting process.
👉 Explore Casita Coalition Insights
San Diego ADU Rent Data
Local rent trends for ADUs across neighborhoods, helping homeowners estimate ROI and plan for affordable rental housing or family use. These insights can also guide decisions about financing, whether through traditional construction loans or an ADU Finance Program.
👉 Explore detailed San Diego ADU rent data and affordability analysis (CHPD)

Framing of an ADU under construction in a backyard – Resources for Homeowners.

Rely on trusted resources like Information Bulletin 400 and the HCD ADU Handbook to navigate zoning regulations and avoid unpermitted ADU issues.

Conclusion

Building an ADU in San Diego can seem overwhelming at first, but with the right preparation and support, the process becomes both manageable and rewarding. From understanding the Zoning and Land Use Regulations and local city ordinance updates to navigating permit fees, inspections, and construction standards, homeowners who plan carefully are well-positioned to benefit from added living space, rental income, and long-term resale value.

At Better Place Design & Build, we specialize in guiding homeowners through every step—whether you’re pursuing a detached unit in an RS Zone, exploring opportunities under the Bonus ADU Program, or ensuring compliance with updated setback rules and solar PV system requirements. With over 15 years of expertise, our team provides full project management support, ensuring your ADU is designed, permitted, and built to code. The result is a smoother experience, greater confidence, and the chance to bring your vision to life while boosting property value and creating much-needed affordable rent options for the community.

Modern ADU kitchen interior with custom cabinetry – Conclusion.

A well-designed ADU not only adds rental income potential but also maximizes long-term resale value—design decisions directly impact ROI.

Frequently Asked Questions

Yes. Every ADU in San Diego requires a building permit from the City’s Development Services Department. The permit ensures your unit complies with state ADU laws, local zoning, safety standards, and building codes. You cannot legally build or rent out an ADU without completing this approval process.

Permit-related costs typically range from about $6,000 to $20,000 depending on size and scope. These fees include the application, plan review, and permit issuance, and in some cases impact or utility connection fees. Smaller ADUs under 750 sq. ft. are exempt from most impact fees, which helps reduce the overall cost.

Most ADU permits in San Diego take about 3–5 months to process from application to approval. This is a major improvement from past years when average waits were closer to 7–10 months. Using pre-approved ADU plans or submitting complete documents upfront can shorten the timeline significantly.

San Diego homeowners may be eligible for the California Housing Finance Agency’s ADU Grant Program. This program provides up to $40,000 to help cover pre-construction costs such as design, permits, site prep, and utility hookups. Funding is limited and distributed through participating lenders, so homeowners should apply early to take advantage of the assistance.