Building an ADU in the City of Roseville

What you can build here

Roseville's ADU rules are in Zoning Code Chapter 19.60. The city last rewrote it with Ordinance 7075, adopted May 20, 2026. Older city handouts, such as the Planning Division's ADU zoning requirements handout, still show the 2024 rules (for example "1 per lot" and two detached ADUs on apartment lots). Where they differ, the code text below is newer.

ADUs are "principally permitted" in the CMU, R1, RS, R2, R3 and RMU zones on a lot with an existing or proposed single-family, two-family or multifamily home. They are also allowed in the NC, CC, GC and HC commercial zones when the home has a conditional use permit; otherwise the ADU needs an Administrative Permit. ADUs are not allowed in industrial zones.

On a single-family lot the code allows:

• one ADU inside the house or an existing accessory structure (such as a garage), which may grow by up to 150 sq ft for getting in and out,
• one junior ADU, and
• one new detached ADU of up to 800 sq ft with 4 ft side and rear setbacks.

These match the combination state law requires; see our California page. If you build an ADU under the regular standards instead (for example, a bigger attached ADU), the code allows one ADU.

On a lot with an existing apartment building, you can add up to eight detached ADUs, but no more than the number of existing units, and convert non-living space (storage rooms, attics, basements or garages) into at least one ADU or up to 25% of the existing units. With a proposed apartment building, the limit is two detached ADUs.

ADUs may also be manufactured homes, efficiency units or tiny houses, as long as they meet the ADU definition, which includes a permanent foundation (or a permanent chassis for a manufactured home). For splitting a lot under SB 9, see our SB 9 lot split guide. [1][5][6]

Size, height and setbacks

New construction (detached, or an attached addition):

• Size: at least 150 sq ft. No more than 850 sq ft of livable space for a studio or one-bedroom, or 1,000 sq ft for more than one bedroom, "except as otherwise provided in Government Code Section 66323." An attached ADU also can't exceed 50% of the floor area of the house.
• Setbacks: 4 ft from side and rear lot lines, including attached porches, decks, balconies and stairs. No setback is needed if you rebuild in the same footprint and size as an existing accessory structure.
• Height: the limit for your zone. Roseville's zoning table sets 35 ft in R1, RS and R2 and 45 ft in R3 (35 ft for units next to the R1 and RS zones).
• Lot size and coverage: no minimum lot area and no maximum lot coverage for ADUs.

Inside an existing structure: no setback is required, and any expansion is limited to 150 sq ft for getting in and out. The code says an ADU inside the house can't be more than 50% of the house's floor area. HCD's January 2026 letter said size caps can't be applied to ADUs built under the state's combination rules (Gov. Code 66323), which include conversions of existing space, so ask the city how the 50% limit applies to your project.

State minimums still apply. The code waives size percentages, lot coverage, floor-area ratio, open space, front setbacks and minimum lot size if they would block an 800 sq ft ADU with 4 ft side and rear setbacks. Its height floor is 16 ft for a detached ADU, 18 ft within a half mile of a major transit stop or high-quality transit corridor (plus 2 ft to match the roof pitch), and up to 25 ft for an attached ADU.

Appearance. The code says an ADU "shall be designed and constructed with the same architectural style, exterior materials and colors as the primary dwelling." State law allows only objective design standards for ADUs.

Ask the Planning Division at (916) 774-5276 or planningdivision@roseville.ca.us about height, setbacks and other planning rules for your lot. [1][2][6][7][8]

Parking

Under the 2026 code, a studio ADU needs no parking. An ADU with one or more bedrooms needs one off-street space, which can be in the front setback or in tandem in the driveway.

No parking is required at all when the ADU:

• is inside an existing structure or living area, or is part of the house or an existing accessory structure,
• is within a half-mile walk of public transit,
• is in the Old Town Historic District (DT-4) or the Central Business District (DT-6),
• is in an area where on-street parking permits are required but not offered to the ADU's occupant,
• is within one block of a car share vehicle, or
• is applied for together with a new single-family or multifamily home.

If you demolish or convert a garage, carport or parking space to build an ADU, you don't have to replace it. Junior ADUs need no parking. [1]

Fees

Roseville's code says ADU fees are charged under "the Accessory Dwelling Units Fee Policy adopted by the City Council on April 21, 2021 by Resolution No. 21-146, as amended from time to time." The city's ADU submittal handout says "Impact fees from a variety of development departments may apply." State law says ADUs of 750 sq ft of interior livable space or less pay no impact fees, and larger ADUs pay in proportion to the size of the main home.

Get a free estimate. Email the Building Division at buildingdivision@roseville.ca.gov for a fee estimate, or use the residential estimate request form on the Development Impact Fees page. The first estimate and the first update are free; later updates cost $212 an hour.

An example. As required by state law (AB 2234), the city posts a sample approved permit for a new detached ADU: a 998 sq ft unit issued in February 2023 with total payments of $15,615.27. That total includes a $1,156.98 building permit fee; most of the rest is regional and city impact fees, such as a $4,185.88 "TMF - Infill" fee and a $2,819 parks fee. Fees have changed since then, so treat it only as an example.

Utilities: a converted ADU doesn't need its own new utility connection unless it is built with a new home. For new construction, a separate connection is required only if the city's utility or electric department directs it. If the existing lines lack capacity, you pay to upgrade them.

Sidewalks. The Building Division's submittal handout (revised April 22, 2026) says "New accessory dwelling unit construction greater than 400 square feet requires installation of curb, gutter, and sidewalk, if none exists." The May 2026 code says "No public physical improvements shall be required for the creation or conversion of an accessory dwelling unit, including, but not limited to, sidewalk, street, or access improvements." The code is newer; confirm with the Building Division.

For budgeting, see our ADU cost and ADU financing guides. [1][6][8][9][10]

How long it takes

You need a building permit for every ADU and junior ADU. The code says it is processed under state ADU law.

The city's Plan Check page says standard plan review "typically takes approximately 3 weeks for first review, and 2 weeks for subsequent reviews." With a pre-approved ADU plan, the city says it will approve or deny a complete application within 30 days, with 10 business days for the first review and 5 business days for each later round.

State law says the city must tell you within 15 business days whether your application is complete, and must approve or deny a complete ADU application within 60 days when there is already a home on the lot. See our ADU permit process guide. [1][3][4][6]

Pre-approved ADU plans

Under state law AB 1332, Roseville posts pre-approved ADU plans that designers have had approved for use in the city. On October 9, 2026 the page listed one: permit BD25-4920, a 748 sq ft detached two-bedroom ADU by Selective Ventures LLC, with the designer's contact information.

These plans are not city-owned. You still need site-specific approval: a site plan, zoning compliance, utility services, fire sprinklers (where required) and a solar (photovoltaic) layout. The city's checklists for using a pre-approved plan were marked "in process of completion," so contact the Building Division at (916) 774-5332 with questions. [3]

Garage conversions and junior ADUs

You can turn an existing garage, storage area, carriage house, pool house or studio into an ADU. No setback is required inside the existing footprint, no parking is required, and you don't have to replace the garage parking. A demolition permit for a detached garage being replaced by an ADU is reviewed with the ADU application and issued at the same time. See our garage conversion guide.

A junior ADU (JADU) can be up to 500 sq ft of livable space, built within the walls of a single-family home, including an attached garage. One JADU is allowed per single-family lot. It needs a separate entrance and an efficiency kitchen. If it doesn't have its own bathroom, it also needs an inside door to the main living area.

Owner occupancy. The 2026 code requires the owner to live in the house or the JADU only if the JADU shares bathroom facilities. That matches current state law. (The city's older zoning handout still says the owner must always live there.) After final inspection, a deed restriction is recorded with the Placer County Recorder; it bars selling the JADU separately and limits its size. See our junior ADU guide.

Fire sprinklers. Sprinklers aren't required in an ADU or JADU if they weren't required for the house, and adding one doesn't trigger sprinklers in the house. [1][5][6]

Renting or selling your ADU

ADUs and JADUs may be rented "as long as the rental term exceeds 30 calendar days." The city won't issue short-term rental permits for them.

An ADU can't be sold separately from the house unless it meets the state's narrow exception for units built by a qualified nonprofit with long-term affordability limits (Gov. Code 66341).

State law bars cities from requiring owners to live on a property because it has an ADU. Adding an ADU may raise your property taxes; see our ADU property tax guide. [1][6]

State review of Roseville's ADU rules

On January 6, 2026, the state housing agency (HCD) sent Roseville a findings letter saying its 2024 ADU ordinance (No. 6829) "fails to comply with State ADU Laws." HCD said the city had to allow all the state ADU combinations, add exceptions to its size caps, drop the subjective rule that an ADU be "subordinate" to the house, add all of the state's parking exemptions, fix its fire sprinkler rule and allow up to eight detached ADUs on existing apartment lots.

The city's May 20, 2026 code update (Ordinance 7075) rewrote the sections HCD flagged. We did not find an HCD response to the new ordinance. If a city rule seems to conflict with state law, ask the city and see our California page. [1][2]

Permit steps in Roseville

1. Check zoning and planning rules

   Email planningdivision@roseville.ca.us or call the Planning Division at (916) 774-5276 about height, setbacks and other planning requirements for your lot. [5][8]

2. Request a fee estimate

   Email buildingdivision@roseville.ca.gov, or send the residential fee estimate request form from the Development Impact Fees page. The first estimate is free. [8][9]

3. Prepare plans

   Have plans drawn, or use a pre-approved plan. The city's submittal list includes a plot plan (property lines, easements, utilities, native oak trees), floor plan, elevations, foundation and roof plans, Title 24 energy forms, an electric load worksheet and waterline calculations. [3][8]

4. Apply online

   Register and submit the building permit application through the city's OPS Portal; see the Online Building Permit Process page for instructions. [11]

5. Plan review

   Expect about 3 weeks for the first review and 2 weeks for each resubmittal, or 10 and 5 business days with a pre-approved plan. [3][4]

6. Pay fees, build and pass inspections

   Pay permit and impact fees when the permit is issued, then build and schedule inspections. For a junior ADU, record the deed restriction with the Placer County Recorder after final inspection. [1][10]

Pre-approved and sample plans

• Preapproved ADU Plans (AB 1332)

  Designer-owned detached ADU plans pre-approved by the city; one listed in October 2026 (748 sq ft, two bedrooms). Site-specific review is still required. [3]

Who to call

• Development Services, Planning Division

  Zoning, height and setback questions for ADUs; email planningdivision@roseville.ca.us

  (916) 774-5276

  311 Vernon Street, Roseville, CA 95678

  [5][8]

• Development Services, Building Division

  Building permits, fee estimates, plan check and pre-approved ADU plans; email buildingdivision@roseville.ca.gov

  (916) 774-5332

  311 Vernon Street, Roseville, CA 95678

  [3][8]

Questions people ask