Everything homeowners need to know about building an accessory dwelling unit in Roseville - size limits, setbacks, permits, and where the city's own ordinance still has some catching up to do with state law.
Last verified: August 2026
6/10 · ADU-friendly
1,000 sq ft
Max ADU size
16 ft*
Max height
Not required
Owner-occupancy
By-right
Permit type
This page summarizes Roseville Municipal Code Chapter 19.60 (Accessory Dwelling Units) and California's statewide ADU law for general reference - it is not legal advice. Regulations change; always confirm current requirements with the City of Roseville Development Services 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, studio or 1-bedroom
850 sq ft
16 ft typically; two-story detached units allowed in some zones
Minimum size 150 sq ft
Detached, 2+ bedrooms
1,000 sq ft
16 ft typically; two-story detached units allowed in some zones
4 ft rear and interior side setback for new construction
Junior ADU (JADU)
500 sq ft
Same as primary structure
Must be built within the walls of the existing house
Allowed zoning districts
Permitted with an existing primary residence in CMU, R1, RS, R2, R3, and RMU residential zones, and in NC, CC, GC, HC, and CBD commercial zones where an existing residence has an approved conditional use permit. Confirm your parcel's zoning with Development Services.
Additional standards
Setbacks, parking & other rules
Setbacks
4 ft from rear and interior side property lines for new construction; conversions of legally established structures are generally exempt from added setbacks
Parking
1 off-street space per unit or per bedroom, whichever is less, for units with a bedroom; studios need none; waived within a half-mile walk of transit
Units per lot
1 ADU plus 1 JADU on a qualifying single-family lot, consistent with the statewide framework
Owner-occupancy
Not required for a standard ADU since a 2020 ordinance update, reinforced by California's 2024 AB 976. A JADU generally requires owner-occupancy unless it has its own bathroom, per 2026's AB 1154
Rental terms
ADUs must be rented for more than 30 calendar days; the city does not issue short-term rental permits for ADUs
Building code
Newly constructed ADUs must comply with all applicable local building and fire codes, including the current California Residential Code
Ordinance history
How Roseville's ADU rules got here
2017Statewide ADU law takes effect. California Government Code section 65852.2 required Roseville, like every city in the state, to approve qualifying ADUs ministerially.
2018Local ordinance adopted. Roseville formalized its own ADU standards in Chapter 19.60 of the municipal code.
2020Owner-occupancy requirement removed. As of January 1, 2020, Roseville no longer required the property owner to live in either the main house or the ADU, ahead of it becoming a statewide mandate years later.
2024Ordinance No. 6829 adopted. The City Council approved an updated ADU ordinance on June 19, 2024, intended to bring the code current with recent state legislation.
2026HCD finds the updated ordinance non-compliant. A January 6, 2026 findings letter concluded that Ordinance No. 6829's fire-sprinkler language conflicted with Government Code section 66314(d)(12), which bars an ADU from triggering new sprinkler requirements in the existing primary home. The city had until February 5, 2026 to respond, and the Planning Commission has since recommended amendments to the City Council to bring the ordinance into compliance.
Worth knowing: Roseville was an early mover on removing owner-occupancy rules back in 2020, but its most recent ordinance update ran into a real compliance problem with the state. As of the most recent public reporting, the fix was still moving through the City Council - ask Development Services directly whether the amended ordinance has been adopted before you finalize a design that depends on the disputed provision.
Permit process
How Roseville ADU permitting works
1
Pre-application check
Confirm your zoning district and any lot-specific constraints with Development Services, (916) 774-5332 or buildingdivision@roseville.ca.gov, before designing.
2
Consider a preapproved plan
Roseville maintains a preapproved ADU plan program under state law (AB 1332), which can shorten design and review time versus a fully custom project.
3
Prepare your plan set
You'll need a site plan, floor plans and elevations for the ADU, and supporting documentation to confirm the size and setback calculations.
4
Submit your building permit application
Applications are reviewed administratively, with no public hearing required. Plan check has typically run around 6-8 weeks; state law sets a 60-day outer limit, with deemed-approval provisions under SB 543 if the city misses it.
5
Plan review & permit issuance
The city checks your submittal for zoning and building code compliance before issuing the building permit.
6
Construction & inspections
Once permitted, schedule the standard framing, plumbing, electrical, and final inspections through Development Services.
Fees and timelines are approximate and subject to change, including a 1.31% construction cost index fee adjustment effective July 1, 2026 - confirm current figures with Development Services.
Budgeting
What it costs to build an ADU in Roseville
Garage conversion
Roughly $70,000-$185,000, the least expensive path since the shell already exists
Basement/addition conversion
Roughly $100,000-$225,000, depending on existing structure and utility access
New detached ADU
Roughly $155,000-$300,000+ for a code-compliant, freestanding unit
Permit fees
Roughly $3,500-$12,000 depending on project scope and valuation
These are general ranges from local contractor estimates and regional reporting, not quotes - actual cost depends heavily on lot conditions, finishes, and whether utilities need to be extended.
Before you apply
Tips for a smooth approval
Ask about the fire-sprinkler rule directly. Given HCD's 2026 non-compliance finding on this exact issue, get Development Services' current written position on whether your ADU can trigger sprinkler requirements in the main house before you finalize plumbing and fire protection design.
Check whether your unit needs a bedroom-based parking space. Roseville still requires off-street parking for most ADUs with a bedroom, unlike some neighboring cities that have dropped it entirely - confirm if your lot qualifies for the transit-proximity waiver.
Size your unit to the bedroom-count cap. A studio or 1-bedroom tops out at 850 sq ft, 150 sq ft smaller than the 2-bedroom-plus cap - plan your layout around the right tier from the start.
Look into the preapproved plan program. Using a plan the city has already vetted under AB 1332 can meaningfully shorten your review timeline.
Plan rental terms around the 30-day minimum. Roseville won't issue short-term rental permits for ADUs, so budget and design for a standard long-term tenant.
FAQ
Common questions
Do I need to live on the property to build an ADU in Roseville?
No. Roseville dropped its owner-occupancy requirement for standard ADUs back in 2020, and California's AB 976 made that permanent statewide in 2024. A JADU generally still requires owner-occupancy unless it has its own bathroom, under 2026's AB 1154.
What's the maximum size for a detached ADU in Roseville?
850 sq ft for a studio or 1-bedroom unit, or 1,000 sq ft for a unit with 2 or more bedrooms, with a 150 sq ft minimum.
Do I need parking for an ADU?
Usually yes - one space per unit or per bedroom, whichever is less - unless it's a studio, or the ADU sits within a half-mile walk of a transit stop.
How long does the permit process take?
Plan check has typically run around 6-8 weeks, and state law caps ministerial review at 60 days, with deemed-approval provisions if the city misses that window. Confirm current timelines with Development Services.
Is it true HCD found problems with Roseville's ADU ordinance?
Yes. In a January 6, 2026 findings letter, the California Department of Housing and Community Development concluded that Roseville's 2024 ADU ordinance (No. 6829) improperly allowed the city to require fire sprinklers in the existing primary home when an ADU is added, which conflicts with state law. The city was required to respond by February 5, 2026, and amendments have been moving through the Planning Commission and City Council since. Confirm the ordinance's current status with Development Services before relying on it.
How much does an ADU cost to build in Roseville?
Garage conversions tend to run roughly $70,000-$185,000, basement or addition conversions $100,000-$225,000, and new detached units $155,000-$300,000 or more, based on local contractor estimates and regional reporting - not counting permit fees.
Can I rent my ADU out on Airbnb or a short-term rental platform?
No. Roseville requires ADU rentals to run more than 30 calendar days and does not issue short-term rental permits for accessory dwelling units.
Are preapproved ADU plans available in Roseville?
Yes. The city maintains a preapproved ADU plan program required by state law (AB 1332), which can reduce design cost and review time compared to a fully custom plan.
Does Roseville require a public hearing to approve my ADU?
No. Qualifying ADU applications are reviewed administratively by staff, without a public hearing, consistent with California's ministerial, by-right approval requirement.
