San Diego County ADU Guide

Imperial Beach

The City has pre-approved a set of ADU plans and operates a preapproval program under AB 1332.

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

Choose the right production starting point.

The City has pre-approved a set of ADU plans and operates a preapproval program under AB 1332.

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.

City materials describe detached new-construction ADUs up to 1,200 square feet, attached ADUs at 50 percent of the main residence or up to 800 square feet, conversions of existing space up to 1,200 square feet, and junior ADUs up to 500 square feet. Confirm which figure applies to the proposed unit type.

Fees require confirmation with Community Development. Coastal review may add time and cost.
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.

  • Coastal Development Permit requirements
  • Whether a pre-approved plan suits the lot
  • Zoning and lot configuration
  • Flood and drainage conditions
  • Fire access and utility service
04 / Consultant screen

Likely disciplines to evaluate.

  • Structural engineering
  • Title 24 energy documentation
  • Survey
  • Coastal or civil consultation 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.