What are the legal steps and permit requirements for building an Accessory Dwelling Unit (ADU) on my property in California?

Building an ADU in California requires preparing compliant architectural plans and obtaining a building permit from your local city or county government. State law streamlines this process, but you must follow your local jurisdiction's specific rules. Step 1: Research Local Requirements Contact your local city or county planning department to get a copy of their ADU ordinance and application checklist. While state law provides a framework, your local government sets specific rules for things like setbacks, height limits, and architectural styles. You can usually find these documents on the department's website. Step 2: Create Compliant ADU Plans Hire a qualified architect, designer, or licensed contractor to create a full set of construction plans. These plans must include a site plan, floor plans, elevations, and structural details. Ensure the plans comply with both the California Building Code and your local ADU ordinance. Step 3: Submit Your Permit Application Complete the building permit application form provided by your local building department. Submit the application along with several copies of your plans and any other required documents, such as a soils report or structural calculations. You will need to pay initial plan check and application fees at this time. Step 4: Undergo Plan Check Review Your local agency has 60 days from the date they deem the application complete to approve or deny your ADU permit. If the plan reviewer requests corrections, work with your designer to address them quickly and resubmit the revised plans. Step 5: Receive Permit and Begin Construction Once your plans are approved, you will pay the final permit fees and receive your official building permit. You may then begin construction. You must schedule and pass all required inspections with the building department throughout the construction process, from foundation to final inspection. Important considerations: State law requires local agencies to use objective, "ministerial" standards for approval, meaning they cannot subjectively deny a compliant project. Additionally, state law limits parking requirements and utility connection fees, especially for smaller ADUs. Note: If your property is part of a Homeowners' Association (HOA), you must still follow their rules, although they cannot unreasonably prohibit the construction of an ADU. Always verify all requirements with your local jurisdiction before spending significant money on plans. This is general information and does not constitute legal advice. For complex situations, consult with a qualified California attorney.