Sacramento ADU Permit Process: A Complete Step-by-Step Guide (2026)

Why Understanding the Permit Process Matters

Building an ADU in Sacramento without proper permits can result in fines of up to $5,000 per violation, forced demolition, and complications when selling your home. The good news is that California's ADU laws have dramatically simplified the process. Since AB 68 and SB 13 took effect, Sacramento must approve or deny ADU permits within 60 days of a complete application. Here's exactly how to navigate each step.

Step 1: Pre-Application Research (Week 1)

Before spending money on plans, verify your property qualifies. Visit the Sacramento County Assessor's website to confirm your lot's zoning designation. All residential zones (R-1, R-2, R-3, R-4, R-5) allow ADUs under California state law. Check your lot dimensions and measure available space for setbacks.

• Confirm your property's zoning at the Sacramento County Assessor's website
• Measure your lot and identify potential ADU placement areas
• Check for easements, flood zones, or other restrictions on your title report
• Determine if you want a detached ADU, attached ADU, garage conversion, or JADU
• Research whether your property has any HOA restrictions (HOAs cannot prohibit ADUs but may impose design standards)

Step 2: Design & Engineering (Weeks 2–6)

Hire an architect or use pre-approved plans to create your ADU design. Your plans must include architectural drawings, structural engineering, Title 24 energy compliance calculations, and a site plan showing the ADU's location on your lot. If you're using a pre-approved plan from Sacramento's ADU Ally program, you can skip much of this step.

• Architectural floor plans and elevations
• Structural engineering calculations
• Title 24 energy compliance report
• Site plan showing ADU placement, setbacks, and utilities
• Soil report (if required by your lot conditions)

Step 3: Submit Your Application (Week 6)

Submit your complete application package to the Sacramento Community Development Department. You can submit online through the city's permit portal or in person. Include all required documents, plans, and the application fee. As of 2026, the initial plan check fee ranges from $1,500–$3,000 depending on project size.

Step 4: Plan Review (Weeks 7–14)

Sacramento has 60 days from the date of a complete application to approve or deny your ADU permit. During this period, plan reviewers will check your submission against building codes, zoning requirements, and fire safety standards. You may receive a correction letter requesting changes — this is normal and doesn't reset the 60-day clock.

• Building code compliance review
• Zoning and setback verification
• Fire safety review (especially for ADUs near property lines)
• Utility connection review (SMUD for electric, city for water/sewer)
• Stormwater management review

Step 5: Address Corrections (If Needed)

If you receive a correction letter, work with your architect or builder to address each item. Common corrections include setback adjustments, structural detail clarifications, and energy compliance updates. Respond promptly — delays in corrections are the #1 reason ADU permits take longer than expected.

Step 6: Permit Issuance & Fee Payment

Once your plans are approved, you'll receive a permit issuance notice. Pay the remaining permit fees and impact fees (if applicable). ADUs under 750 sq ft are exempt from impact fees. For larger ADUs, impact fees are calculated proportionally based on the ADU's size relative to the primary dwelling. Total permit and fee costs typically range from $5,000–$15,000.

Step 7: Construction & Inspections

With your permit in hand, construction can begin. Your builder will schedule inspections at key milestones: foundation, framing, rough plumbing/electrical, insulation, and final inspection. Each inspection must pass before the next construction phase can proceed.

• Foundation inspection before pouring concrete
• Framing inspection after walls and roof structure
• Rough plumbing, electrical, and mechanical inspections
• Insulation and energy inspection
• Final inspection for certificate of occupancy

Step 8: Certificate of Occupancy

After passing the final inspection, you'll receive a Certificate of Occupancy (CO). This document confirms your ADU meets all building codes and is safe for habitation. You can now legally rent your ADU or use it for any permitted purpose. Keep your CO in a safe place — you'll need it for insurance, refinancing, and future property sales.

Common Mistakes to Avoid

Based on our conversations with Sacramento ADU builders, here are the most common mistakes that delay projects or increase costs:

• Starting construction before permits are approved (illegal and can result in stop-work orders)
• Not checking utility capacity before designing — sewer and water connections can add $5,000–$15,000
• Ignoring setback requirements — 4-foot side and rear setbacks are required for new construction
• Skipping the soil report on properties with fill dirt or clay soil
• Not budgeting for the 'soft costs' — permits, engineering, and design typically add 10–15% to total project cost