El Cajon, CA
El Cajon ADU Permit Fee Calculator (2026)
Instant fee breakdown for El Cajon, California. Total range: $3,800–$10,500.
El Cajon, California ADU Permit Fees
Total estimated range: $3,800–$10,500
Plan Check
$800–$2,000
Building Permit
$1,000–$3,000
Impact Fees
Waived (< 750 sf)
School Fees
$2–$4/sf
Utility Hookups
$2,000–$5,500
Source: City permitting schedules and FeeBuilder surveys, updated April 2026.
El Cajon permit process at a glance
Permitting office: El Cajon Community Development Department
Typical plan review: 8-14 weeks
Fee waivers: ADUs under 750 sq ft are exempt from impact fees per AB 681.
El Cajon is one of the easier permit paths in San Diego County — Community Development typically runs 8-14 weeks, and the city has adopted a pre-approved ADU plan program with about 8 published designs. AB 681 impact-fee waivers apply. Helix Water District serves most of El Cajon and has its own meter and connection fee schedule separate from the City of San Diego Water.
Sample real-world fee example
Scenario: 700 sq ft detached ADU on 7,000 sq ft El Cajon lot
| Plan check | $1,000 |
| Building permit | $1,500 |
| School fees ($2.85/sf) | $1,995 |
| Sewer connection | $2,200 |
| Helix Water meter | $2,300 |
| TOTAL | $8,995 |
Common El Cajon ADU permit mistakes
- Skipping the Title 24 energy compliance docs at submittal — adds 4-6 weeks of correction cycles.
- Confusing the AB 681 impact-fee waiver — it only applies to ADUs strictly under 750 sq ft of conditioned floor area.
- Missing the separate water-meter and sewer-capacity applications, which run on a parallel track from the building permit.
- Confusing Helix Water District vs. City of San Diego Water — Helix has its own meter and connection fee schedule.
- Skipping the El Cajon pre-approved ADU plan catalog if eligible.
How El Cajon compares nearby
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