Unincorporated only: This page covers the unincorporated area of Sacramento County — parcels outside any city, regulated by the County Planning / Land Use Services Department. If your address is inside a city (Sacramento), use that city's ADU page instead.
These rules apply to UNINCORPORATED Sacramento County - Arden-Arcade, Carmichael, Fair Oaks, Orangevale, Antelope, North Highlands, Rio Linda, Florin, Rosemont, Vineyard and the Delta towns - not to the cities of Sacramento, Elk Grove, Folsom, Citrus Heights, Rancho Cordova, Galt or Isleton, which have their own ADU codes. Under Zoning Code Sec. 3.9.3.D and Table 5.11 (Sec. 5.4.5.B, last amended July 11, 2024) every lot with a house or halfplex may add one ADU plus one JADU as an accessory use by right in every zoning district: a detached ADU up to 1,200 sq ft, 16 ft tall (18 or 20 ft with extra setback or near transit), 4 ft from side and rear lines, with a ministerial building permit that state law (Gov. Code 66317) requires the County to decide within 60 days. Impact fees are waived at 750 sq ft or less (Gov. Code 66311.5), and the County gives away five pre-checked Shelf Ready plan sets from 460 to 1,184 sq ft for use in the unincorporated area only. Where the 2024 County text is stricter than the 2025-2026 state amendments (multifamily unit counts, JADU owner-occupancy), state law controls; the County's Sept 10, 2026 Zoning Code update did not touch the ADU sections.
Zoning & Size Requirements [1][2][3][4][5][6][7]
Yes — unincorporated Sacramento County allows ADUs. A detached ADU can typically be up to 1,200 sq ft under California state law and the County's zoning code.
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| Where ADUs Are Allowed | Every zoning district: Table 3.2 lists 'Dwelling Unit, Accessory / Junior Accessory' as an accessory use by right (A) in AG, UR, IR, AR, RD-1 through RD-40, RM-2, RR, O, C-O, NMC, CMC, CMZ, BP, LC, GC, MP, M-1 and M-2. In zones where a house is not itself a permitted use, an ADU is allowed only on a lot with a legally established existing dwelling whose primary use is residential (Table 3.2 footnote [1]). Standards are in Sec. 3.9.3.D and Sec. 5.4.5.B / Table 5.11. |
| Max Size (Detached) | 1,200 sq ft for new construction, with no increase allowed even by Special Development Permit (Table 5.11 footnote [5]); minimum 150 sq ft habitable; single story only (footnote [8]). Converting an existing permitted structure: its floor area plus 150 sq ft for entry. State law guarantees at least an 800 sq ft detached unit with 4 ft setbacks on any lot (Gov. Code 66323(a)(2)). |
| Max Size (Attached) | The greater of 50% of the primary dwelling's habitable square footage or 800 sq ft (Table 5.11); minimum 150 sq ft; single story. Gov. Code 66321(b)(2) bars a cap below 850 sq ft (1,000 sq ft for two or more bedrooms), so the County's 800 sq ft floor is overridden by the state figure - confirm the number with SacPlan before designing. |
| Max Size (JADU) | 500 sq ft of space inside the primary dwelling, including an attached garage or storage area, plus 150 sq ft for entry; no deviations (Table 5.11 footnote [7]). Needs its own exterior entrance and at least an efficiency kitchen; a JADU without its own bathroom must also have an interior door to the house. A deed restriction barring separate sale is recorded before permit final. |
| Max Height | Detached: 16 ft to peak; 18 ft within 1/2 mile walking distance of a major transit stop or to match the primary house's roof pitch (Planning Director approval); 20 ft if set back at least 10 ft from the rear line and 5 ft from the side lines. Attached: 25 ft. ADU on a multifamily lot: 18 ft. Detached and attached ADUs must be single story (Table 5.11 footnote [8]); anything taller needs a Special Development Permit. |
| Max Units | House or halfplex lot: 1 ADU (attached or detached) + 1 JADU (Sec. 3.9.3.D). Duplex or multifamily lot: County text says 2 new detached ADUs plus conversions of non-living space up to 25% of existing units, but Gov. Code 66323(a)(4) (SB 1211, Jan 1, 2025) requires up to 8 detached on an existing multifamily lot (never more than the unit count), 2 on a proposed one; Sec. 3.9.3.D defers to state law. SB 9 lots (Sec. 5.4.7): 2 units per parcel after a lot split, up to 4 without one. |
Setback & Parking Requirements [1][2][3][4][5][6][7]
Unincorporated Sacramento County requires a rear setback of about 4 ft for a detached ADU, and parking requirements vary by unit size or location. Owner-occupancy is not required — you can rent it out without living on the property.
| Rear Setback | 4 ft, measured from the wall to the property line, with up to a 24-inch roof overhang allowed into the setback (Table 5.11 footnote [10]). Under 5 ft the Fire District and Building may require rated walls or limits on windows (footnote [9]) - the County's own Shelf Ready plan sets are drawn for 5 ft minimum without fire sprinklers, 4 ft with. Existing structures converted to an ADU keep their permitted setbacks; a 10 ft rear setback (with 5 ft sides) unlocks 20 ft of height. |
| Side Setback | 4 ft interior side (same 24-inch overhang and under-5-ft fire-rating rules as the rear). Street side on a corner lot: 12.5 ft (Table 5.11), unless a Special Planning Area, Neighborhood Preservation Area or Planned Development ordinance sets its own figure (footnote [12]). The Planning Director may reduce the street-side setback administratively if it would physically prevent an 800 sq ft ADU (footnote [6]). |
| Front Setback | 20 ft (Table 5.11), or the front setback in the applicable SPA, NPA or PD ordinance. An administrative reduction is available when the front setback, lot coverage or open-space rule would prevent an 800 sq ft ADU; a reduction to fit a unit between 800 and 1,200 sq ft needs a Special Development Permit (footnote [6]). |
| Parking Required | One space per ADU, tandem on the driveway allowed (Table 5.11; Gov. Code 66314(a)(10)). Waived within 1/2 mile walking distance of public transit, in a historic district, for an ADU inside the house or an existing accessory structure, where street permit parking is not offered to the ADU, within one block of a car-share vehicle, or when the ADU is permitted with a new primary dwelling. No replacement parking when a garage or carport is converted or demolished. JADUs: none. |
| Owner Occupancy | Not required for an ADU (Table 5.11 imposes none; Gov. Code 66315 forbids it). JADU: Table 5.11 requires the owner to live in the house or the JADU (waived for a government agency, land trust or housing organization), but Gov. Code 66333(b) as amended by AB 1154 (effective Jan 1, 2026) allows that only for a JADU that shares a bathroom with the house - the County text has not been updated, so confirm with SacPlan. |
| Min Lot Size | None. Neither Sec. 3.9.3.D nor Table 5.11 sets a minimum lot size, and Gov. Code 66321(b)(2) bars any lot-size, coverage or open-space rule that would prevent an 800 sq ft ADU. Exception: ADUs and JADUs are not allowed on parcels created through an SB 1123 small-lot subdivision (Sec. 5.4.8). |
Permit Process & Fees [8][9][10][11][12][13][14][15][16][17]
An ADU in unincorporated Sacramento County is approved administratively — no public hearing. The County publishes no ADU review time. State law requires approval or denial within 60 days of a complete application, or the permit is deemed approved (Gov. Code 66317, as amended by SB 543 effective Jan 1, 2026). Shelf Ready plan sets skip structural plan check. Permit fees: Building permit and plan-check fees are valuation-based and not published as an ADU figure; the Shelf Ready page says standard building fees apply even to the free plans, plus a separate PV permit and any Fire District fee. Get a written estimate from Building Permits and Inspection (916-875-5296).
| Approval Process | Ministerial building permit from Building Permits and Inspection - no hearing, no design review (Gov. Code 66317). The County's ADU submittal handout (CO-47) lists the steps: email SacPlan@saccounty.gov for setbacks and height, Technical Resources (dssgeneralinfo@saccounty.gov) for easements, SacSewer (permitservices@sacsewer.com) for the sewer connection, check fees with each department, then apply online through the Citizen Access Portal (aca-prod.accela.com/SACCO). Deviations from Table 5.11 standards other than size need a Planning Director Determination or Special Development Permit. |
| Review Timeline | The County publishes no ADU review time. State law requires approval or denial within 60 days of a complete application, or the permit is deemed approved (Gov. Code 66317, as amended by SB 543 effective Jan 1, 2026). Shelf Ready plan sets skip structural plan check. |
| Permit Fees | Building permit and plan-check fees are valuation-based and not published as an ADU figure; the Shelf Ready page says standard building fees apply even to the free plans, plus a separate PV permit and any Fire District fee. Get a written estimate from Building Permits and Inspection (916-875-5296). |
| Impact Fees | None at 750 sq ft or less of livable space (Gov. Code 66311.5; the County's Shelf Ready page confirms 'ADUs greater than 750 square feet are subject to impact fees'). Above 750 sq ft the fees are area-specific - countywide transportation (SCTDF), library, drainage and Metro Fire fees, park fees in eight recreation and park districts, and plan-area programs in Antelope, Florin Vineyard, Vineyard, North Vineyard Station, Mather and Metro Air Park - so request a Development Impact Fee Calculation from SIPS (916-874-6544). Sewer (SacSewer), water (SCWA Zone 40) and school district fees are charged separately. |
| Plan Check | Full plan review by Building Permits and Inspection to the California codes (site, floor, elevation, foundation and roof-framing plans, Title 24 energy forms, solar plan; engineering if not conventional framing; fire sprinklers go to the local Fire District). Shelf Ready sets were pre-checked to the 2022 California Residential, Electrical, Mechanical, Plumbing and Energy Codes with truss calcs included; the applicant adds only a scaled plot plan, PV plans (Models B, C, D) and a signed Hold Harmless Agreement. Roof trusses and floor plans may not be altered. |
| Pre-Approved Plans | Yes - five free Shelf Ready detached plan sets, unincorporated county only, funded by a state LEAP grant: Model A1 Laurel (460 sq ft studio or 1BR, metal roof), A2 Willow (460 sq ft, pitched roof), B Redwood (870 sq ft, 2BR), C Elderberry (1,000 sq ft, 2BR) and D Magnolia (1,184 sq ft, 3BR). Models B, C and D require a photovoltaic system under a separate permit. Only A1 and A2 are at or under the 750 sq ft impact-fee threshold. |
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Construction Costs [18][19][20][21]
Building an ADU in unincorporated Sacramento County typically costs $170,000-$400,000 ($250-$500 per sq ft); a garage conversion runs $90,000-$200,000.
See what this means for your lot — ask Sacramento County ADU builders for a quote →
Construction costs in unincorporated Sacramento County track the surrounding metro market. Rural parcels can cost more because of septic, well, access and fire-hazard requirements, so treat these as planning ranges and get local bids.
| Average Build Cost | $170,000-$400,000 |
| Cost per Sq Ft | $250-$500 |
| Garage Conversion | $90,000-$200,000 |
| Prefab ADU (Installed) | $170,000-$340,000 |
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Rental Income Potential [22][23]
| Avg Rent (1 Bedroom) | $1,600-$2,200/mo |
| Avg Rent (2 Bedroom) | $1,950-$2,700/mo |
| Short-Term Rental | No for any ADU permitted on or after Jan 1, 2020, and never for a JADU (Zoning Code Sec. 3.9.3.D and 3.9.3.AA; County STR Permit page). |
| Est. Annual ROI | 6-12% gross on a $250,000-$400,000 detached build renting at $1,950-$2,700/mo; a $90,000-$200,000 garage conversion at $1,600-$2,200/mo can gross 10-25% (estimates before taxes, vacancy and financing) |
Recent Law Changes
What's Changed Recently
- Sept 10, 2026: the County's 2023 Zoning Code Update (134 items, approved by the Board of Supervisors in summer 2026) took effect; it changed accessory-structure heights and home occupations but left Sec. 3.9.3.D, Sec. 5.4.5.B and Table 5.11 as amended July 11, 2024
- June 2026 draft, Board hearing estimated Nov 2026: the Housing and Infill Zoning Code Amendment (triplex/fourplex in RD zones, multifamily by right) contains no change to the ADU standards
- June 11, 2026: Sec. 3.5.1.K and 5.4.7 (SB 9 second primary dwellings) added - 2 units per parcel after an urban lot split, up to 4 with an ADU and JADU when there is no split
- Jan 1, 2026: SB 543 rewrote Gov. Code 66317 (60-day decision, deemed approved) and AB 1154 limited JADU owner-occupancy to units that share a bathroom with the house (Gov. Code 66333(b)); the County's Table 5.11 still shows the old JADU rule
- Jan 1, 2025: SB 1211 raised the state minimum to 8 detached ADUs on an existing multifamily lot (Gov. Code 66323(a)(4)); Table 5.11 still reads 2 and defers to state law
- July 11, 2024: the current County ADU/JADU standards (Sec. 3.9.3.D, 5.4.5.B, Table 5.11) took effect; the Shelf Ready plan program followed in late 2024
Tips for Building an ADU in Unincorporated Sacramento County
- Check jurisdiction first on the County's online parcel map: Arden-Arcade, Carmichael, Fair Oaks, Orangevale, Antelope, North Highlands, Rio Linda, Florin, Rosemont, Vineyard, Courtland and Walnut Grove are unincorporated (County rules); an address inside Sacramento, Elk Grove, Folsom, Citrus Heights, Rancho Cordova or Galt follows that city's code
- Keep the unit at 750 sq ft or less of livable space to owe no impact fees; the only free plan sets that qualify are the 460 sq ft Laurel and Willow - the 870 sq ft Redwood, 1,000 sq ft Elderberry and 1,184 sq ft Magnolia trigger area-based impact fees, so ask SIPS for a fee calculation before choosing
- Zoning allows a 4 ft side and rear setback, but without fire sprinklers the Shelf Ready plans need 5 ft to avoid fire-rated walls; if your house has no sprinklers the ADU (up to 1,200 sq ft detached) does not need them either, per the plan sets and CRC R313.2 - the Fire District makes the final call
- A new ADU cannot be an Airbnb: County Zoning Code Sec. 3.9.3.D bars short-term rental (30 days or less) of any ADU permitted on or after Jan 1, 2020 and of every JADU; plan on tenants of 30 days or longer
- Cost basis: Sacramento-area contractor guides dated April-June 2026 (detached $250-$500 per sq ft, garage conversions from about $90,000, prefab installed $170,000-$340,000); the free plan sets remove design fees but not building, PV, sewer or impact fees. Rents are HUD FY2026 Small Area FMRs for unincorporated ZIPs 95608, 95628, 95662, 95821, 95825 and 95843
- Cost basis (2026-09-20 re-verification): short term allowed: No for any ADU permitted on or after Jan 1, 2020, and never for a JADU (Zoning Code Sec. 3.9.3.D and 3.9.3.AA; County STR Permit page). An ADU legally permitted before 2020 may be rented short-term (29 days or less) only with a County Short-Term Rental Permit and business licence, on a property the owner or a long-term tenant occupies at least six months a year. Stays of 30 days or more are ordinary rentals, registered with the Rental Housing Inspection Program.
ADU Builders in Sacramento County
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Cities Within Sacramento County
If your property is inside one of these incorporated cities, follow that city's ADU code — not the County rules above:
Sources & References
All data on this page is sourced from official government records and verified market data. View our full methodology.
- Sacramento County Zoning Code Ch. 5 (Sec. 5.4.5.B, Table 5.11 and footnotes; Sec. 5.4.7 SB 9; Sec. 5.4.8 SB 1123) Planning Department — Accessed 2026-09-20
- Sacramento County Zoning Code Ch. 3 (Sec. 3.9.3.D ADUs and JADUs; Sec. 3.9.3.AA Short-Term Rentals; Sec. 3.2.2) Planning Department — Accessed 2026-09-20
- Sacramento County Zoning Code Table 3.2, Allowed Accessory Uses (amended Sept 10, 2026) Planning Department — Accessed 2026-09-20
- Gov. Code 66323 (converted, detached and multifamily ADUs; SB 1211 eight-unit rule) State Law — Accessed 2026-09-20
- Gov. Code 66321 (size, height and setback floors) State Law — Accessed 2026-09-20
- Gov. Code 66314 (parking cap) and 66315 (no owner-occupancy for ADUs) State Law — Accessed 2026-09-20
- Gov. Code 66333 (JADUs; AB 1154 owner-occupancy limit) State Law — Accessed 2026-09-20
- Sacramento County - Shelf Ready ADU Plans (Building Permits and Inspection, posted July 9, 2026) Planning Department — Accessed 2026-09-20
- Sacramento County CO-47 Accessory Dwelling Unit Submittal Requirements (rev. 1/2024) Planning Department — Accessed 2026-09-20
- Sacramento County AP-37 ADU, Duplex and Townhome Plan Submittal Requirements (AB 2234) Planning Department — Accessed 2026-09-20
- Sacramento County Shelf Ready Model A2 Willow plan set (cover sheet: codes, setbacks, sprinkler notes) Planning Department — Accessed 2026-09-20
- Sacramento County Development Impact Fees (SIPS fee programs and calculation request) Planning Department — Accessed 2026-09-20
- Sacramento County Short Term Rental Permits (ADU and JADU eligibility) Planning Department — Accessed 2026-09-20
- Sacramento County - More Than You Think: What the Recent Zoning Code Changes Mean for Residents (Aug 13, 2026; effective Sept 10, 2026) Planning Department — Accessed 2026-09-20
- Sacramento County Housing and Infill Zoning Code Amendment (June 2026 draft; schedule) Planning Department — Accessed 2026-09-20
- Gov. Code 66317 (60-day ministerial review; SB 543) State Law — Accessed 2026-09-20
- Gov. Code 66311.5 (impact-fee exemption at 750 sq ft or less) State Law — Accessed 2026-09-20
- How Much Does It Cost to Build an ADU in Sacramento (updated April 28, 2026) industry — Accessed 2026-09-19
- How Much Does an ADU Cost in Sacramento? (updated June 12, 2026) industry — Accessed 2026-09-19
- How Much Does an ADU Cost in Sacramento in 2026? industry — Accessed 2026-09-19
- Garage Conversion ADU in Sacramento: Complete 2026 Guide industry — Accessed 2026-09-19
- HUD FY2026 Small Area Fair Market Rents, Sacramento--Roseville--Arden-Arcade HUD Metro FMR Area (ZIPs 95608, 95628, 95662, 95821, 95825, 95843) Government Data — Accessed 2026-09-20
- HUD FY2027 Small Area Fair Market Rent Schedule (effective Oct 1, 2026) Government Data — Accessed 2026-09-20
- Sacramento County Land Use Regulation Library (Zoning Code home; 2023 Zoning Code Update effective Sept 10, 2026) Planning Department — Accessed 2026-09-20
Frequently Asked Questions
What are the ADU rules in unincorporated Sacramento County?
In unincorporated Sacramento County, ADUs are regulated by the County (not a city) and follow California state ADU law. A detached ADU can be up to 1,200 sq ft for new construction, with no increase allowed even by Special Development Permit, attached ADUs up to The greater of 50% of the primary dwelling's habitable square footage or 800 sq ft. Rear setbacks are 4 ft, measured from the wall to the property line, with up to a 24-inch roof overhang allowed into the setback, and qualifying ADU applications are approved administratively, with no public hearing.
How much does an ADU permit cost in Sacramento County?
In unincorporated Sacramento County, building and plan-check fees scale with the size and valuation of the ADU, so there is no single flat fee — request the current fee schedule from the County. None at 750 sq ft or less of livable space (Gov. Code 66311.5; the County's Shelf Ready page confirms 'ADUs greater than 750 square feet are subject to impact fees'). Above 750 sq ft the fees are area-specific - countywide transportation (SCTDF), library, drainage and Metro Fire fees, park fees in eight recreation and park districts, and plan-area programs in Antelope, Florin Vineyard, Vineyard, North Vineyard Station, Mather and Metro Air Park - so request a Development Impact Fee Calculation from SIPS (916-874-6544). Sewer (SacSewer), water (SCWA Zone 40) and school district fees are charged separately.. Total construction typically runs $170,000-$400,000; a garage conversion is cheaper at $90,000-$200,000.
Do I need owner-occupancy for an ADU in Sacramento County?
Not required for an ADU (Table 5.11 imposes none; Gov. Code 66315 forbids it). JADU: Table 5.11 requires the owner to live in the house or the JADU (waived for a government agency, land trust or housing organization), but Gov. Code 66333(b) as amended by AB 1154 (effective Jan 1, 2026) allows that only for a JADU that shares a bathroom with the house - the County text has not been updated, so confirm with SacPlan..
Is my property in unincorporated Sacramento County or inside a city?
This matters a lot: if your parcel is inside an incorporated city (Sacramento), that city's ADU code applies instead of the County's. Only unincorporated parcels follow the County rules on this page. Confirm your jurisdiction with the County before designing.
How many ADUs can I build in unincorporated Sacramento County?
House or halfplex lot: 1 ADU (attached or detached) + 1 JADU (Sec. 3.9.3.D). Duplex or multifamily lot: County text says 2 new detached ADUs plus conversions of non-living space up to 25% of existing units, but Gov. Code 66323(a)(4) (SB 1211, Jan 1, 2025) requires up to 8 detached on an existing multifamily lot (never more than the unit count), 2 on a proposed one; Sec. 3.9.3.D defers to state law. SB 9 lots (Sec. 5.4.7): 2 units per parcel after a lot split, up to 4 without one.
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