Building an ADU in the City of Elk Grove

What you can build here

Elk Grove's ADU rules are in Municipal Code Chapter 23.90, last updated by Ordinance 13-2025, effective July 25, 2025. ADUs are allowed "in all residential, agricultural residential, and agricultural zoning districts," on a lot zoned for mixed-use, single-family or multifamily use with a proposed or existing home. The city's Community Development Director approves them through zoning clearance and plan check.

An ADU must have a kitchen, a place to sleep and a full bathroom. It can be attached, inside the house or an accessory building (including an attached garage), or detached.

On a single-family lot the code allows:

• one ADU and one junior ADU inside the proposed or existing house or an existing accessory structure, with up to 150 sq ft added for getting in and out, and
• one new detached ADU, which can be combined with a junior ADU.

State law requires every city to allow at least one ADU made from existing space, one junior ADU and one new detached ADU together on a single-family lot. Elk Grove's code mentions combining the detached ADU only with a junior ADU, so if you want all three, confirm with the Planning Division.

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

An existing house may be redesignated as the ADU when you build a new main house, if the old house meets the ADU size limits. For the statewide rules, see our California page; for lot splits, see our SB 9 lot split guide. [1][2][4]

Size, height and setbacks

• Minimum size: 150 sq ft.
• Attached ADU: up to 50% of the house's floor area, or 850 sq ft (one bedroom or less) or 1,000 sq ft (more than one bedroom), whichever is greater.
• Detached ADU: up to 1,200 sq ft.
• Side and rear setbacks: 4 ft for new construction. Front and street-side setbacks follow your zone. No added setback is needed when you convert existing space or rebuild a structure in the same place and size.
• Height, attached: 25 ft or the height of the house, whichever is greater.
• Height, detached: generally 16 ft. Inside the allowed building envelope and outside the required yards, it may go up to the zone's height limit. Within a half-mile walk of a major transit stop or high-quality transit corridor, 18 ft plus 2 ft to match the house's roof pitch. In agricultural and agricultural-residential zones, 30 ft.

Fire separation. The city's FAQ says that if an ADU is within 5 ft of a property line or another building, the building code's fire separation and fire-resistant construction rules apply.

Design. The code says ADUs "shall be compatible with the architectural style, materials, and colors of the primary dwelling unit." State guidance says only objective design standards may be applied to ADUs.

Ask the Planning Division at (916) 478-2265 or planner@elkgrove.gov about setbacks on your lot. [1][2][4][5]

Parking

Elk Grove's code says an ADU must provide "one (1) additional off-street parking space for each bedroom" unless one of these applies, in which case no parking is required:

• within a half-mile walk of public transit, including any bus stop,
• in an architecturally and historically significant historic district,
• part of the existing house or an existing accessory structure,
• on-street parking permits are required but not offered to the ADU occupant,
• a car share vehicle is within one block, or
• the ADU is applied for together with a new home on the same lot.

Any required space can be tandem on an existing driveway. Junior ADUs need no parking, even when made from an attached garage, and you don't have to replace garage parking you convert.

Check the per-bedroom rule. State law says ADU parking "shall not exceed one parking space per unit or bedroom, whichever is less." The city's per-bedroom wording could ask for more than that for a two-bedroom ADU, so confirm with the Planning Division. [1][2][4]

Fees

The city's ADU page says "ADUs under 750 square feet are exempt from development impact fees. For ADUs 750 square feet or larger, development impact fees may be applied proportionally based on the ratio of the ADU's square footage to that of the primary residence." That covers city fees only. State guidance says the exemption covers an ADU with "750 square feet of interior livable space or less," so ask the city before you design at exactly 750 sq ft.

Other agencies charge their own fees. The city lists school district impact fees (paid directly to the district, such as Elk Grove Unified), the Cosumnes Fire Department, the Sacramento County Sanitation District, Sacramento County Technical Resources, and Sacramento County Environmental Management for lots with wells or septic tanks. State guidance says ADUs under 500 sq ft of interior livable space are not subject to school impact fees.

Get an estimate. Email a completed Residential Fee Quote Worksheet to bldonline@elkgrove.gov; the city says to allow up to 48 hours. The city says its pre-approved plans also give "a lower cost permit process."

See our ADU cost and ADU financing guides for budgeting. [2][3][4]

How long it takes

Plans are submitted electronically. A permit technician checks within 48 hours whether your submittal is complete. Incomplete submittals are not held; you resubmit a complete package.

For plan review, the city says to "allow a minimum of ten (10) business days for the initial plan review and five (5) business days for each subsequent review," plus 24-48 hours of processing after each submittal. Before the permit is issued you also need approvals from outside agencies, which the city lists when your submittal is complete.

State law says a city 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. [2][4]

City pre-approved ADU plans

Elk Grove offers pre-approved plans for detached ADUs:

• Plan 1: studio, 435 sq ft
• Plan 2: 1 bedroom, 625 sq ft
• Plan 3: 2 bedrooms, 746 sq ft

The plan sets list the 2025 California building codes. The city says using them allows "an expedited review process, and a lower cost permit process." The plans "cannot be revised and must be permitted as designed." You still provide a site plan for your lot and Title 24 energy documents, and you need planning and zoning approval. If the energy report calls for solar panels, they need a separate permit that must be issued and inspected before the ADU's Certificate of Occupancy.

Designers can also get their own ADU plans pre-approved for use in Elk Grove through the city's ADU plan pre-approval process for designers. [3][6]

Garage conversions and junior ADUs

You can convert an attached or detached garage, storage area or other existing space into an ADU. No new setback is required for the existing structure, and no replacement parking is needed. If the lot is too small for a detached ADU, the city suggests attaching one to the house or building one above the garage. See our garage conversion guide.

A junior ADU (JADU) must be within the walls of a single-family home (attached garages count), up to 500 sq ft, with a separate entrance and an efficiency kitchen. If it has no bathroom of its own, it needs an inside door to the main living area. Only one JADU is allowed per single-family lot, and it can't be expanded beyond the house's existing walls or built in a detached accessory structure.

Owner occupancy. Elk Grove's code says the owner must live in the house or the JADU, and a deed restriction is recorded. Since January 1, 2026, state law requires owner occupancy only when the JADU shares a bathroom with the house. Confirm with the Planning Division. See our junior ADU guide.

Fire sprinklers. The city says ADUs don't need sprinklers if the house doesn't have them. If a new house and ADU are built together, both need sprinklers. For details, contact the Cosumnes Fire Department. [1][2][4]

Renting out your ADU

An ADU may be rented separately from the house, but "Rentals shall be for terms of thirty (30) days or longer." The city's FAQ says "both the existing house and the ADU can be rental units," except that the owner must live on a property with a JADU (see above).

An ADU generally can't be sold separately from the house. The code allows a separate sale only under the state's nonprofit affordable-housing exception (it cites the old Gov. Code 65852.26, now 66341).

Have an older ADU built without permits? The city says you may be able to legalize it; contact the Planning and Building divisions. State law limits when a city can deny a permit for an unpermitted ADU built before January 1, 2020. An ADU may also raise your property taxes; see our ADU property tax guide. [1][2][4]

Permit steps in Elk Grove

1. Check zoning and setbacks

   Confirm your zone and setbacks with the Planning Division at (916) 478-2265 or planner@elkgrove.gov. Rules are in Chapter 23.90. [1][5]

2. Get a fee estimate

   Email a completed Residential Fee Quote Worksheet to bldonline@elkgrove.gov. [2][3]

3. Prepare plans

   Use a city pre-approved plan or have plans drawn. Include a to-scale site plan with property lines, all buildings and their distances, trees to be removed, utilities and easements, and the main electrical panel, plus Title 24 energy documents. [2][3]

4. Submit electronically

   Upload the permit application, addressing application, plans and documents to the Building Division Filedrop. A permit technician checks completeness within 48 hours. [2]

5. Plan review and outside agency approvals

   Answer any plan review comments with a revised plan set and a written response to each comment. Get the outside agency approvals the city lists. [2]

6. Pay fees and receive the permit

   Once outstanding items are done and final fees are paid, the city emails the permit and stamped plans. Print them for the inspector. [2]

7. Inspections and Certificate of Occupancy

   Schedule inspections at (916) 478-2225 or through eTrakit. Any separate solar permit must be finaled before the ADU's final inspection; then the city emails the Certificate of Occupancy. [2]

Pre-approved and sample plans

• City Pre-Approved ADU Plans

  Three detached ADU plans from the city (435 sq ft studio, 625 sq ft one-bedroom, 746 sq ft two-bedroom) drawn to the 2025 codes; must be built as designed. [3][6]

Who to call

• Building Safety and Inspection Division

  ADU building permits, plan review and fee estimates; email bldonline@elkgrove.gov

  (916) 478-2235

  8401 Laguna Palms Way, Elk Grove, CA 95758

  [2][5]

• Planning Division

  Zoning, setbacks and ADU options for your lot; email planner@elkgrove.gov

  (916) 478-2265

  [5]

Questions people ask