San Diego County · Updated April 2026
San Diego ADU Permit Fees: $6,500–$21,000
Complete breakdown of every permit fee, timeline, and how to save thousands with pre-approved plans.
Quick Answer
San Diego ADUs: $200K–$400K
Permits: $6.5K–$21K · Updated April 2026
San Diego ADU Permit Fees: Overview
San Diego ADU permit fees range from $6,500 to $21,000 depending on the size and type of your ADU. Fees are split across multiple city departments — plan check, building inspection, schools, and utilities each collect separate charges. The good news: California's Senate Bill 13 (SB 13) waives all impact fees for ADUs 750 square feet or smaller, which is the most common ADU size in San Diego. Both the City of San Diego and San Diego County offer pre-approved ADU plan programs that can reduce your design costs and cut plan review time significantly.
ADU permit fees are separate from construction costs. Total ADU build costs in San Diego run $200,000–$400,000 for a complete detached unit. The permit fees are a relatively small but unavoidable part of your total budget.
San Diego ADU Permit Fee Breakdown (2026)
| Fee Type | Under 500 sq ft | 750 sq ft | Notes |
|---|---|---|---|
| Plan Check | $2,300 | $7,539 | City Development Services |
| Building Permit / Inspection | $2,200 | $7,834 | Scales with project valuation |
| School Fee (SD Unified) | $0 | ~$1,295 | $5.17/sq ft for >500 sq ft |
| Water Capacity (0.5 EDU) | $1,524 | $1,524 | City Water utility |
| Sewer Capacity (0.5 EDU) | $2,577 | $2,577 | City Sewer utility |
| Address Assignment | $435 | $435 | One-time fee |
| Estimated Total | ~$6,500 | ~$21,000 | SB 13 waives impact fees ≤750 sq ft |
Fee estimates based on 2026 City of San Diego schedule. Actual fees vary by project valuation and location within city limits vs. unincorporated county.
Total Permit Cost by ADU Size
| ADU Size | Estimated Permit Fees | Impact Fee Waiver? |
|---|---|---|
| 400 sq ft (Studio) | ~$6,500 | Yes — SB 13 |
| 750 sq ft (1 BR) | ~$21,000 | Yes — SB 13 |
| 1,200 sq ft (2 BR) | $21,000+ | Proportional fees apply |
Pro tip: Keeping your ADU at or under 750 sq ft triggers SB 13 impact fee waivers, which can save thousands. Most 1-bedroom ADUs fit comfortably in 600–750 sq ft.
ADU Permit Fee Comparison: San Diego County Cities
| City | Permit Fee Range | Approx. Timeline |
|---|---|---|
| San Diego (City) | $8,500–$12,000 | 6–8 weeks |
| Chula Vista | $8–$15 / sq ft | Varies |
| El Cajon | $12–$14 / sq ft | Varies |
| Carlsbad | $9,000–$13,500 | Varies |
| Escondido | $7,500–$10,500 | Varies |
Each city has its own fee schedule. Rates shown are estimates for a standard 750 sq ft detached ADU. Confirm current fees with the city's planning or building department.
Pre-Approved ADU Plans in San Diego
Both the City of San Diego and San Diego County offer pre-approved ADU plan programs. These are architect-designed, code-compliant plans already reviewed and approved by the relevant jurisdiction — homeowners select a design, pay a licensing fee, and submit directly for building permit without a full custom plan check.
Pre-Approved Plans
- Design cost savings: $5,000–$15,000
- Plan check: 2–3 weeks
- Pre-reviewed for code compliance
- Lower risk of plan check corrections
Custom Plans
- Design cost: $15,000–$40,000+
- Plan check: 4–8 weeks
- Full design flexibility
- Risk of correction cycles adding weeks
For most homeowners building a standard 1-bedroom ADU, pre-approved plans are the faster and more cost-effective path. Custom plans make sense for unusual lots, complex programs, or when architectural integration with the main home is a priority.
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Get Your EstimateSan Diego ADU Permit Process: Step by Step
Design & Plans
Hire an architect or select a pre-approved city/county plan. Pre-approved plans save 4–6 weeks and $5K–$15K in design fees.
Submit to City or County
Submit plans through the City of San Diego's Development Services Department or San Diego County's Planning & Development Services (for unincorporated areas).
Plan Review
Standard plan review takes 4–8 weeks. Pre-approved plans are reviewed in 2–3 weeks. Corrections may add additional rounds of review.
Pay Permit Fees
Fees are collected at permit issuance. Prepare for $6,500–$21,000 in total permit costs depending on ADU size.
Permit Issuance
Receive your building permit. Post the permit on-site — construction cannot begin until the permit is issued.
Construction
Build your ADU. Inspections are required at foundation, framing, mechanical/electrical/plumbing rough-in, and insulation stages.
Final Inspection
The city building inspector conducts a final walk-through to verify code compliance across all systems.
Certificate of Occupancy
Once final inspection passes, the city issues a Certificate of Occupancy — your ADU is legally habitable and can be rented.
San Diego ADU Requirements
Maximum Size
1,200 sq ft (detached)
Rear & Side Setbacks
4 feet minimum
Height Limit
16 feet
Approval Type
Ministerial (no hearing)
Owner Occupancy
Not required (state law)
Impact Fees
Waived for ≤750 sq ft (SB 13)
Frequently Asked Questions
What is the total permit cost for a San Diego ADU?
Total permit fees range from approximately $6,500 for a small ADU under 500 sq ft to $21,000 for a 750 sq ft unit. The main cost drivers are plan check fees ($2,300–$7,539) and building permit fees ($2,200–$7,834), which both scale with ADU size and project valuation. Utility connection fees (water and sewer) add roughly $4,100 regardless of size.
How long does the ADU permit process take in San Diego?
Standard custom plans take 4–8 weeks for plan check review. Pre-approved plans from the city or county program are reviewed in 2–3 weeks. From design start to Certificate of Occupancy, most projects run 6–12 months total, with construction taking the majority of that time.
Does San Diego offer pre-approved ADU plans?
Yes — both the City of San Diego and San Diego County offer pre-approved ADU plan programs. These designs are already code-reviewed, so the plan check stage is significantly faster (2–3 weeks vs. 4–8 weeks). You save $5,000–$15,000 in architect design fees and reduce the risk of costly plan check correction cycles.
Are impact fees waived for ADUs in San Diego?
Yes. California's Senate Bill 13 (SB 13) requires cities and counties to waive impact fees for ADUs 750 square feet or smaller. For ADUs larger than 750 sq ft, impact fees are charged proportionally — the ADU's fee is calculated as a fraction of the main home's impact fee, based on relative square footage.
Are City of San Diego and San Diego County fees the same?
No. The City of San Diego and the unincorporated areas served by San Diego County have separate fee schedules and permitting departments. City permits are handled through the City's Development Services Department, while county properties use San Diego County Planning & Development Services. If your property is within a city like Chula Vista, El Cajon, or Carlsbad, those cities have their own independent fee structures.
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