01 / Plan pathChoose the right production starting point.
The City publishes an ADU handbook and permit applications through the Planning Division. ADUs are generally allowed in most single-family residential zones; Planning counter staff can confirm a specific property's zoning.
Express PlanStarting at $4,500For a qualifying jurisdiction preapproved plan adapted into the property-specific architectural production set.
Custom PlanStarting at $6,500For an original floor plan and architectural production set developed around the property and homeowner.
Size affects more than floor area.
ADU and JADU provisions sit at National City Municipal Code 18.30.380 and 18.30.390. A JADU is defined as not less than 150 and not more than 500 square feet within an existing or proposed single-family dwelling.
Fees require confirmation with the Planning Division at 619-336-4310.
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 conditionsProperty conditions can change the path.
- Zoning confirmation for the specific parcel
- Lot configuration and existing dwelling
- Fire access and utility service
- Airport influence area where applicable
04 / Consultant screenLikely disciplines to evaluate.
- Structural engineering
- Title 24 energy documentation
- Survey where boundaries require it
- Civil or acoustic 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 stepTurn 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.
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.