California ADU rules · Yolo County
Can I Build an ADU in Winters?
Yes — you can build an ADU in Winters. California's statewide ADU law requires every city, including Winters, to approve a qualifying accessory dwelling unit by right, plus a junior ADU (JADU) on a single-family lot. What varies city to city are the local specifics below.
Can you build one?
ADUs allowed
CA state lawYes — by right
ADUs and JADUs are allowed by right in all residential and mixed-use zones; ministerial approval, no hearing.
Units on a single-family lot
Local rule1 ADU only; JADU allowed per state fallback
Winters code allows only 1 ADU per single-family lot; JADUs not addressed locally but required by state.
Units on a multifamily lot
CA state lawConversion ADUs (≥1, up to 25% of units) + up to 8 detached
Conversions of non-livable space (at least 1, or up to 25% of existing units) plus up to 8 detached ADUs on a lot with existing multifamily — never exceeding the number of existing units. JADUs are single-family only.
Junior ADU (JADU)
CA state lawAllowed
Up to 500 sq ft, within the walls of an existing single-family home (single-family lots only).
Size & height
Max detached ADU size
Local rule1,200 sq ft
Local cap is 1,200 sq ft for detached ADUs.
Max attached ADU size
Local rule50% of primary, not to exceed 1,200 sq ft
Local rule is 50% of primary residence, max 1,200 sq ft; state minimums still apply.
Guaranteed minimum size
CA state law800 sq ft
An 800 sq ft ADU must be allowed regardless of FAR/lot-coverage caps; a city also cannot cap an attached ADU below 850 sq ft (1,000 for 2+ bedrooms).
Max JADU size
CA state law500 sq ft
Max height
Local rule16 ft
Detached ADUs limited to 16 ft if 800 sq ft or less; above-garage ADUs may be up to 5 ft from side/rear lines.
Setbacks
Side setback
Local rule4 ft
4 ft side/rear setbacks for detached ADUs ≤800 sq ft and ≤16 ft tall.
Rear setback
Local rule4 ft
4 ft side/rear setbacks for detached ADUs ≤800 sq ft and ≤16 ft tall.
Front setback
CA state lawNo front setback may block the mandatory 800 sq ft / 16-ft / 4-ft-setback ADU; otherwise per base zone
Separation from main house
CA state lawNone required
No statewide separation requirement between the ADU and the primary dwelling.
Parking
Parking required
Local ruleNone
No off-street parking required for ADUs.
Transit parking exemption
CA state lawYes — no parking required near transit & for conversions
No parking may be required within ½ mi walking distance of transit, in a historic district, for an ADU within an existing structure, within one block of car-share, or in certain permit-parking areas.
Garage-conversion replacement parking
Local ruleNot required
No replacement parking required for garage/carport conversions.
Approval, timeline & cost
Approval path
CA state lawMinisterial (by right)
No public hearing or discretionary design review for a qualifying ADU.
Approval timeline
Local rule60 days
60-day ministerial approval timeline.
Owner-occupancy
Local ruleNot required
No owner-occupancy required for ADUs permitted between Jan 1, 2020 and Jan 1, 2025; required after Jan 1, 2025.
Impact-fee waiver
Local ruleWaived under 750 sq ft
No impact fee for ADUs under 750 sq ft.
Permits required
Local ruleBuilding permit
Building permit required; application to Community Development Director.
Winters allows only one ADU per single-family lot and sets a 1,200 sq ft cap for both detached and attached ADUs. No off-street or replacement parking is required, and owner-occupancy will be required for ADUs permitted after Jan 1, 2025.
Frequently asked questions
Can I build an ADU in Winters?
Yes. California's statewide ADU law requires Winters to approve a qualifying accessory dwelling unit ministerial (by right), plus a junior ADU (JADU) on a single-family lot.
How big can an ADU be in Winters?
A detached ADU of at least 1,200 sq ft must be allowed, and an ADU of 800 sq ft can never be zoned out by floor-area or lot-coverage limits. A JADU can be up to 500 sq ft.
What are the setback requirements for an ADU in Winters?
Side and rear setbacks are limited to 4 ft. No front setback may block the mandatory 800 sq ft / 16-ft / 4-ft-setback ADU; otherwise per base zone.
Is parking required for an ADU in Winters?
None. No parking can be required within ½ mile of transit, for conversions, or for units inside the primary home. When a garage is converted, replacement parking is not required.
How long does ADU approval take in Winters?
A complete application must be acted on within 60 days, with ministerial (by right) — no public hearing or discretionary design review for a qualifying ADU.
Do I have to live on the property to build an ADU in Winters?
Owner-occupancy: not required. ADUs under 750 sq ft are also exempt from impact fees.
Sources
- Winters Municipal Code Chapter 17.98 (Accessory Dwelling Units); Ord. 2020-01 § 3(b) (part)
- Winters Municipal Code § 17.98.030(A)
- Winters Municipal Code § 17.98.030(B)
- Winters Municipal Code § 17.98.030(C)
- Winters Municipal Code § 17.98.030(I)
- Winters Municipal Code § 17.98.020(B)(3)
- Winters Municipal Code § 17.98.030(K)
- Winters Municipal Code § 17.98.030(M)
- Winters Municipal Code § 17.98.020(A)
- Cal. Gov. Code §§ 66310–66342 (ADU Law)
- HCD 2025 Accessory Dwelling Unit Handbook
- Cal. Gov. Code § 66317 (ministerial approval, 60-day deadline)
- Cal. Gov. Code § 66323 (by-right ADU/JADU, 800 sq ft, 4-ft setbacks)
- Cal. Gov. Code § 66333 (junior ADUs)
- Cal. Gov. Code § 66321 (size minimums & height)
- Cal. Gov. Code § 66322 (ADU parking; § 66334 covers JADU parking)
Last updated 2026-06-25. This is an AI-assisted summary of Winters's ADU rules, drawn from its published ordinance and California ADU law — general information, not legal advice, and it may be incomplete or out of date. Verify the controlling rule for your specific parcel with Winters Planning before relying on it.
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