How to Plan Your ADU in Sacramento: A Step-by-Step Guide

Adding an accessory dwelling unit (ADU) to your Sacramento property is one of the smartest investments a homeowner can make right now. Whether you want rental income, space for aging parents, or a private home office, an ADU delivers real value — and California's updated laws have made them more accessible than ever.

But "accessible" doesn't mean simple. Between zoning rules, permit requirements, utility connections, and design decisions, the planning process has a lot of moving parts. This guide walks you through each step so you know exactly what to expect before you break ground.

What Is an ADU and What Types Are Allowed in Sacramento?

An ADU is a secondary residential unit on a single-family or multifamily lot. In Sacramento, you can build several types:

• Detached ADU — a standalone structure in the backyard, separate from the main home
• Attached ADU — an addition connected to the primary residence
• Garage conversion — converting an existing attached or detached garage into living space
• Junior ADU (JADU) — a smaller unit (up to 500 sq ft) created within the existing home footprint

Each type has different size limits, setback requirements, and design standards. The right choice depends on your lot size, existing structures, and goals.

Step 1: Understand Your Zoning and Lot Requirements

Before you spend a dollar on design, confirm what your lot allows. In Sacramento County and the City of Sacramento, most single-family residential zones permit at least one ADU and one JADU per lot — but the specifics vary.

Key things to check:

• Lot size minimums — some jurisdictions require a minimum lot size for a detached ADU
• Setbacks — how far the ADU must sit from property lines (typically 4 feet from rear and side)
• Height limits — detached ADUs are generally capped at 16–18 feet
• Owner-occupancy rules — California eliminated owner-occupancy requirements for ADUs built before 2025, but rules can shift

Your local planning department's website is a starting point, but the rules are dense. A drafting professional who works in Sacramento regularly can read your specific parcel and tell you exactly what's possible in a fraction of the time.

Step 2: Define Your ADU Goals and Budget

Once you know what's allowed, get clear on what you actually want. Ask yourself:

• Is this for rental income, family use, or personal use?
• Do you want a studio, one-bedroom, or two-bedroom unit?
• What's your realistic budget — including design, permits, construction, and utility connections?

ADU costs in Sacramento typically range from $150,000 to $350,000+ depending on size, type, and finishes. Garage conversions tend to be on the lower end; detached new construction runs higher. Getting a realistic number early prevents painful surprises later.

Step 3: Hire a Drafting Professional to Prepare Your Plans

This is the step most homeowners underestimate. You cannot pull a building permit without a complete set of permit-ready drawings. These drawings must show:

• Site plan with property lines, setbacks, and existing structures
• Floor plans with dimensions and room labels
• Exterior elevations
• Foundation and framing details
• Electrical, plumbing, and mechanical layouts (depending on jurisdiction)

A licensed drafting professional prepares these documents to meet your local building department's specific requirements. Getting this right the first time matters — plan check corrections add weeks to your timeline and money to your budget.

At Liberty Drafting Studios, we've prepared ADU drawings for properties across Sacramento, El Dorado, Placer, and surrounding counties. We know what each jurisdiction expects, and we design to those standards from the start.

Step 4: Submit for Permits and Navigate Plan Check

Once your drawings are complete, you (or your drafting professional) submit them to the local building department for plan check. The reviewer examines your plans for code compliance and either approves them or issues correction comments.

Typical plan check timelines in Sacramento:

• City of Sacramento: 4–8 weeks for standard review; express review available for an additional fee
• Sacramento County: 4–10 weeks depending on workload
• Folsom, Elk Grove, Roseville: varies by jurisdiction

If corrections are required, your drafting professional responds to each comment and resubmits. This back-and-forth is normal — but having well-prepared plans minimizes the number of rounds.

Step 5: Coordinate Utility Connections

An ADU needs its own utility connections or shared connections with the main home, depending on the type and jurisdiction. This typically involves:

• Water and sewer — a new lateral or connection to the existing system; may require a capacity fee
• Electrical — a new panel or subpanel for the ADU
• Gas — if the unit will have gas appliances

Utility fees can add $10,000–$30,000 or more to your project cost, so factor them in early. Your drafting professional can help coordinate with utility companies and ensure your plans reflect the required connections.

Step 6: Select a Contractor and Begin Construction

With permits in hand, you're ready to hire a licensed general contractor. Get at least three bids, check references, and verify their contractor's license with the California Contractors State License Board (CSLB).

During construction, your building department will require inspections at key milestones — foundation, framing, rough electrical and plumbing, and final. Your contractor manages these, but it helps to stay engaged and ask questions.

Common ADU Planning Mistakes to Avoid

After working with dozens of Sacramento homeowners, we see the same mistakes come up repeatedly:

Starting design before checking zoning. It's easy to fall in love with a floor plan before confirming it's even allowed on your lot. Always verify zoning first.

Underestimating permit timelines. Plan check takes time. If you're counting on rental income by a specific date, work backward from that date and build in buffer.

Choosing the cheapest designer. Permit-ready drawings require experience and local knowledge. Saving a few hundred dollars on design often costs thousands in correction rounds and delays.

Ignoring utility costs. Capacity fees and connection costs are real. Get estimates from your utility providers before finalizing your budget.

How Liberty Drafting Studios Can Help

Planning an ADU involves a lot of decisions, and the permit process can feel overwhelming if you haven't done it before. That's where we come in.

We prepare complete, permit-ready ADU drawings for Sacramento-area homeowners — from initial site analysis through final permit approval. We know the local jurisdictions, we communicate clearly, and we design plans that get approved.

If you're thinking about an ADU and want to understand what's possible on your property, we're offering a free project consultation. No pressure — just a real conversation about your goals and what it takes to get there.

Request your free consultation today and let's talk about your project.