01 / Plan pathChoose the right production starting point.
The Planning Division administers ADU review. The City passed an ordinance in July 2023 updating ADU development standards for consistency with state law, and reports the standards are undergoing further updates.
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.
Current standards sit at Simi Valley Municipal Code 9-44.160. Because the ordinance is being updated, confirm the standards in force with the Planning Division at 805-583-6769 before design.
Fees require confirmation with the Planning Division. The City tracks ADUs under Government Code 65400 and asks owners to complete an occupancy and rents survey as part of permitting.
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.
- Which version of the ADU ordinance is in force at submittal
- Zoning and lot configuration
- Fire hazard severity zone and fire access
- Hillside and grading conditions
04 / Consultant screenLikely disciplines to evaluate.
- Structural engineering
- Title 24 energy documentation
- Survey where boundaries or topography require it
- Geotechnical or civil review in hillside areas
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.