San Diego County ADU Guide

El Cajon

The City offers pre-approved ADU plans through the Planning Division's guidance and forms, and runs an ADU Loan Program for owner-occupied properties.

Official source verified 2026-08-16Official jurisdiction resource ↗
01 / Plan path

Choose the right production starting point.

The City offers pre-approved ADU plans through the Planning Division's guidance and forms, and runs an ADU Loan Program for owner-occupied properties.

Express PlanStarting at $4,500

For a qualifying jurisdiction preapproved plan adapted into the property-specific architectural production set.

Custom PlanStarting at $6,500

For an original floor plan and architectural production set developed around the property and homeowner.

02 / Size + fee checkpoints

Size affects more than floor area.

ADU provisions sit in the City's zoning code, which has been amended to track state law. Confirm the current objective standards with the Planning Division before design.

El Cajon operates an ADU Loan Program providing financial assistance to eligible owner-occupants. Fees and loan eligibility both require confirmation.
500 SFConfirm school-fee assessment rules750 SFState impact-fee protection checkpoint1,000 SFTwo-bedroom state minimum allowance1,200 SFCommon local upper-range checkpoint
03 / Site conditions

Property conditions can change the path.

  • Whether a pre-approved plan suits the lot
  • ADU Loan Program eligibility
  • Zoning and lot configuration
  • Fire access and utility service
04 / Consultant screen

Likely disciplines to evaluate.

  • Structural engineering
  • Title 24 energy documentation
  • Survey where boundaries require it
  • Civil or geotechnical review when triggered

Consultants are retained only when required by the property, design, or reviewing agency. Their proposals and coordination are separate from the architectural production fee unless stated otherwise in the agreement.

05 / Property-specific next step

Turn the guide into a preliminary project report.

Enter the address to screen jurisdiction, mapped constraints, likely agencies, drawing requirements, consultants, and the preliminary fee path.

Check the property →Email Bennett Design Studio →
Important: This guide is general planning information, not a zoning determination, permit approval, fee quote, or guarantee of feasibility. Current parcel records, adopted codes, agency interpretations, utility requirements, site investigation, and written agency confirmation control.