Everything homeowners need to know about building an accessory dwelling unit in Sacramento - size limits, setbacks, permits, and how the city's free preapproved plans can make the process faster and cheaper than almost anywhere else in California.
Last verified: August 2026
9/10 · Very ADU-friendly
1,200 sq ft
Max ADU size
16 ft*
Max height
Not required
Owner-occupancy
By-right
Permit type
This page summarizes Sacramento City Code Section 17.228.105 (Accessory Dwelling Units and Junior Accessory Dwelling Units), layered on top of California's statewide ADU law (Gov. Code Sec 65852.2), for general reference - it is not legal advice. Regulations change; always confirm current requirements with the City of Sacramento's Community Development Department before designing or applying for permits. See sources below.
Zoning & size requirements
What you're allowed to build
ADU type
Max size
Max height
Notes
Detached (new construction)
Up to 1,200 sq ft total, split across up to 2 detached ADUs on one lot (e.g., a 400 sq ft unit plus an 800 sq ft unit)
16 ft general standard; up to 18 ft (plus up to 2 ft for roof pitch) for ADUs built under the state's ministerial pathway
Sacramento allows 2 ADUs (attached and/or detached) per qualifying lot
Attached (addition to primary home)
50% of the primary dwelling's floor area or 850 sq ft, whichever is greater (1,000 sq ft for 2+ bedroom units)
Same as primary structure
Converted (garage, interior)
Sized to the existing structure's footprint
Same as existing structure
Generally exempt from standard new-construction setback rules
Junior ADU
Built within the primary home's existing walls
Same as primary structure
Requires the owner to occupy the JADU or the primary residence
Allowed zoning districts
Allowed citywide on any lot with an existing or proposed primary residential structure. Sacramento also offers a library of free, preapproved "shelf-ready" ADU plans through its Planning Division that have already cleared plan check - confirm your parcel's zoning and eligibility at adu.cityofsacramento.org.
Additional standards
Setbacks, parking & other rules
Setbacks
Minimum 4 ft side and rear setbacks for most new-construction ADUs; front setback follows the underlying zoning district. Conversions of existing legal structures are generally exempt from setback rules
Parking
No additional off-street parking required for an ADU or JADU, including when an existing garage is converted
Units per lot
Up to 2 ADUs (attached and/or detached) plus 1 JADU on a qualifying lot with an existing or proposed primary residence
Owner-occupancy
Not required for a standard ADU; a JADU requires the owner to occupy either the JADU or the primary residence
Building code
Must meet current California Building, Residential, Energy, Plumbing, Mechanical, and Electrical Code standards
Fire sprinklers
Most detached ADUs under 1,200 sq ft are exempt from fire sprinkler requirements if the main home isn't sprinklered
Impact fees
Waived for ADUs under 750 sq ft (state SB 13); applied on a prorated basis above that, plus separate school-district impact fees
Ordinance history
How Sacramento's ADU rules got here
2017Statewide ADU law takes effect. California's Gov. Code Section 65852.2 begins requiring ministerial, by-right approval of qualifying ADUs, and Sacramento updates its zoning code to comply.
2020Local code updated for the AB 68/881 package. Sacramento revises Section 17.228.105 to reflect the eliminated minimum lot size, reduced setbacks, and legalized junior ADUs required under the new statewide standards.
2023Impact-fee waiver expands. Statewide SB 13 protections exempting ADUs under 750 sq ft from development impact fees are in full effect, lowering costs for smaller units citywide.
2024Preapproved ADU program launches. The City of Sacramento rolls out its Preapproved ADU program under state AB 1332, offering free, shelf-ready plans that have already cleared plan check. The same year, statewide AB 976 eliminates owner-occupancy requirements and SB 1211 allows multi-family properties to add multiple detached ADUs.
2026Standards refreshed. The city's ADU handout and fee schedule were revised in January to reflect the current code and impact-fee framework.
Sacramento's biggest practical advantage over many California cities is process speed: pairing a preapproved plan with the city's concurrent plan-review option can move a detached ADU into construction well faster than a fully custom design, since the structural and energy-code review is already done. Statewide, cities now issue more than 20,000 ADU permits a year, roughly a quarter of all housing approvals since the 2017 law took effect.
Permit process
How Sacramento ADU permitting works
1
Pre-application check
Confirm zoning eligibility and check whether a preapproved shelf-ready plan fits your lot at adu.cityofsacramento.org.
2
Prepare your plan set (or pick a preapproved plan)
Custom projects need a full plan set; preapproved plans only require a site-specific site plan.
3
Planning approval or concurrent review
Request concurrent review via a Memorandum of Understanding to run planning and building review in parallel, saving time.
4
Building permit submittal
Submit to the Building Division electronically or at the public counter; a minimum of two full plan sets is required.
5
Plan check & permit issuance
Standard review for code compliance; the city targets a 60-day cycle for complete ADU applications.
6
Construction & inspections
Schedule the standard framing, plumbing, electrical, and final inspections as work proceeds.
Fees and timelines are approximate and change periodically - confirm current figures with the Community Development Department's Help Line before you budget or apply.
Budgeting
What it costs to build an ADU in Sacramento
Garage conversion
Roughly $70,000-$170,000, the least expensive path since the shell already exists
Basement conversion
Roughly $100,000-$210,000, depending on existing ceiling height and utility access
New detached ADU
Roughly $150,000-$320,000+; a preapproved plan can trim design costs and shorten the timeline versus a fully custom design
Impact fees
Waived for ADUs under 750 sq ft; applied on a prorated basis above that, plus separate school-district impact fees that vary by district
Permit fee estimate service
$164 flat fee for a formal building permit fee estimate from the city
These are general ranges from local contractor estimates and regional reporting, not quotes - actual cost depends heavily on lot conditions, finishes, and whether you use a preapproved plan versus a custom design. Sacramento's construction costs tend to run below the Bay Area, though still above the national median.
Before you apply
Tips for a smooth approval
Look at the preapproved plan library first. It can save real money on design and shave weeks off review compared to a fully custom plan.
Keep your ADU under 750 sq ft if cost matters most. It clears the statewide impact-fee waiver threshold entirely.
Ask about concurrent review. Running planning and building review in parallel through the MOU process can meaningfully shorten your timeline.
Check your school district's impact fee before budgeting. Fees vary by district and stack on top of the city's own charges.
Confirm your fire sprinkler exemption early. Most detached ADUs under 1,200 sq ft on an unsprinklered lot are exempt, but it's worth confirming for your specific project.
FAQ
Common questions
Do I need to live on the property to build an ADU in Sacramento?
No, not for a standard ADU. Only junior ADUs carry an owner-occupancy requirement, and even then, exceptions apply for public agencies, land trusts, and housing organizations.
How many ADUs can I build on one lot?
Up to 2 ADUs (attached and/or detached, totaling 1,200 sq ft for detached units) plus 1 junior ADU, as long as there's an existing or proposed primary residence on the lot.
Do I need extra parking for an ADU?
No. Sacramento doesn't require additional parking for an ADU or JADU, even when converting an existing garage.
How long does the permit process take?
Sacramento targets a 60-day review cycle for complete applications. Preapproved plans move faster since the design has already cleared plan check, with some homeowners reporting approval in as little as 30 days.
What's the maximum size for a detached ADU?
Up to 1,200 sq ft total across up to two detached units, with a 16 ft height limit generally (up to 18 ft, plus up to 2 ft for roof pitch, for ADUs built under the state's ministerial pathway).
How much does an ADU cost to build in Sacramento?
Garage conversions tend to run roughly $70,000-$170,000, basement conversions $100,000-$210,000, and new detached units $150,000-$320,000 or more, based on local contractor estimates and regional reporting.
What are the preapproved "shelf-ready" ADU plans?
A library of free ADU floor plans, offered under the state's AB 1332 preapproved ADU program, that have already cleared structural and energy-code plan check. Choosing one instead of a custom design typically means a faster, cheaper path through permitting.
Do I need a special permit to rent my ADU short-term on Airbnb?
Yes. Sacramento requires a Short-Term Rental Permit (around $200/year) for any rental under 30 days, in addition to standard ADU permitting - confirm current rules with the city before you finalize your plans.
Are impact fees really waived for small ADUs?
Yes. Under statewide SB 13, ADUs under 750 sq ft are exempt from development impact fees. Larger units pay a prorated share, and separate school-district impact fees may still apply regardless of size.
