Simi Valley ADU Permit Process - Homeowner Guide

Housing and Building Standards California 3 Minutes Read · published February 21, 2026 Flag of California

Building an accessory dwelling unit (ADU) in Simi Valley, California requires coordination with the City planning and building divisions, compliance with state ADU laws, and submission of required permits and plans. This article explains the standard permit steps, common municipal requirements, enforcement pathways, timelines, and practical action steps for homeowners in Simi Valley. It references official city and state sources so you can find forms, contact information, and the legal basis for approvals and potential penalties.

Start by contacting Planning and Building early to confirm lot-specific constraints.

Overview of the ADU Permit Process

Simi Valley follows California ADU statutes while enforcing local zoning, design, and building standards. Typical stages are preliminary review, planning clearance, building permit application, plan check, inspections, and final occupancy. Specific local requirements and the interaction with state law are established by city planning and building rules and by California Government Code for ADUs.[1][2]

  • Pre-application consultation with Planning and Building to identify zoning limits and utility connections.
  • Submit site plans, floor plans, and elevation drawings with a building permit application.
  • Pay plan check and permit fees as assessed by Building and Safety.
  • Undergo inspections during construction and request final inspection for occupancy.

Penalties & Enforcement

Simi Valley enforces ADU rules through its municipal code and building regulations. Enforcement may include stop-work orders, administrative citations, and requirements to obtain retroactive permits or remove noncompliant construction. Exact fine amounts and daily penalties are not specified on the cited municipal code page or Planning pages and must be confirmed with the City enforcement office.[3]

Unpermitted ADU work can trigger stop-work orders and expensive retroactive remedies.
  • Monetary fines: not specified on the cited page.
  • Escalation: first, repeat, and continuing offences and daily penalties: not specified on the cited page.
  • Non-monetary sanctions: stop-work orders, mandatory removal, or requirement to obtain retroactive permits.
  • Enforcer: City of Simi Valley Planning Division and Building & Safety Division; complaints and inspection requests go through official city channels.
  • Appeals and review: administrative appeal routes exist through Planning Commission or the City; time limits for appeals are set in the municipal code or administrative procedures and should be confirmed with the Planning Division.
  • Defences/discretion: permitted variances, building permits, or reasonable compliance plans may be considered through formal application processes.

Applications & Forms

  • Building permit application: name and number not specified on the cited page; obtain the City building permit packet from Building & Safety.
  • Fees: plan check and permit fees are assessed on submission; specific fee amounts are not specified on the cited page.
  • Submission: most permit applications are submitted to the City of Simi Valley Building & Safety or via the City portal; confirm required attachments with staff.

Action Steps for Homeowners

  • Step 1: Contact the Planning Division for a pre-application review and zoning confirmation.
  • Step 2: Prepare site and construction drawings with a licensed design professional.
  • Step 3: Submit building permit application and required forms to Building & Safety.
  • Step 4: Respond to plan check comments and schedule inspections during construction.
  • Step 5: Obtain final inspection and certificate of occupancy before renting or occupying the ADU.

FAQ

Can I build an ADU on my Simi Valley lot?
Eligibility depends on zoning, lot size, setbacks, and utility availability; contact Planning for a parcel-specific check.
How long does the permit process take?
Timelines vary by project complexity and completeness of submittal; typical plan check cycles and inspections apply.
What if I already built without a permit?
You must contact Building & Safety to discuss retroactive permits, potential fines, and corrective actions.

How-To

  1. Confirm zoning and ADU allowances with the Planning Division.
  2. Gather required plans: site plan, floor plans, elevations, and utility connections.
  3. Submit the building permit application with all supporting documents and pay fees.
  4. Address plan check comments, schedule inspections, and complete construction per approved plans.
  5. Obtain final inspection and certificate of occupancy before use or rental.

Key Takeaways

  • Start with Planning for a parcel-specific ADU feasibility review.
  • Permits, accurate plans, and inspections are required; unpermitted work can lead to enforcement.

Help and Support / Resources

  1. [1] City of Simi Valley Community Development - ADU and planning pages
  2. [2] Simi Valley Municipal Code - Code of Ordinances
  3. [3] State of California Government Code §65852.2 (Accessory Dwelling Units)

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