California ADU rules · San Luis Obispo County
Can I Build an ADU in Paso Robles?
Yes — you can build an ADU in Paso Robles. California's statewide ADU law requires every city, including Paso Robles, 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
CA state law1 ADU + 1 JADU
At least one ADU and one JADU per single-family lot (a conversion ADU may also be possible).
Units on a multifamily lot
Local ruleConverted ADUs: at least 1, up to 25% of existing units from non-livable space; Detached ADUs: up to 2 on a lot with a proposed multifamily dwelling, or up to 8 on a lot with an existing multifamily dwelling (not to exceed the number of existing units)
Detached ADUs on multifamily lots are capped at 2 for proposed buildings and 8 for existing, not to exceed the number of existing units.
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 maximum for detached ADUs on single-family lots is 1,200 sq ft.
Max attached ADU size
Local rule1,200 sq ft or 50% of primary dwelling, whichever is less (single-family); 850/1,000 sq ft for multifamily
Attached ADUs on single-family lots are capped at 1,200 sq ft or 50% of the primary dwelling, whichever is less; multifamily attached ADUs capped at 850/1,000 sq ft.
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
CA state law16 ft
16 ft baseline; cities must allow 18 ft within ½ mi of a major transit stop or where the primary dwelling is two-story, and 20 ft on a lot with a multistory multifamily building.
Setbacks
Side setback
CA state law4 ft
A city cannot require more than 4 ft side or rear setback; conversions of existing structures are exempt.
Rear setback
CA state law4 ft
Front setback
Local rule15 ft (20 ft to garage door); R-1 B-3/B-4/B-5: 20 ft; R-2/R-3/R-4/R-5: 25 ft from arterial street
Front setback varies by zone and street type.
Separation from main house
Local rule6 ft
6 ft minimum separation required between detached ADU and other structures unless attached.
Parking
Parking required
Local ruleUp to 1 space
1 off-street space per ADU required unless exempt.
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 spaces lost to ADU conversion.
Approval, timeline & cost
Approval path
CA state lawMinisterial (by right)
No public hearing or discretionary design review for a qualifying ADU.
Approval timeline
CA state law60 days
The agency must act within 60 days of a complete application — and the ADU is deemed approved if it does not.
Owner-occupancy
Local ruleOnly for a JADU
Owner-occupancy required only for JADUs, not for ADUs.
Impact-fee waiver
CA state lawWaived under 750 sq ft
An ADU of 750 sq ft or less pays no impact fees (the 750 sq ft threshold itself is exempt under § 66311.5); larger ADUs pay fees proportional to the primary dwelling. JADUs (≤ 500 sq ft) are exempt.
Permits required
Local ruleBuilding permit, ADU permit (if not qualifying for building-permit only path)
Some ADUs require both a building permit and an ADU permit.
Paso Robles-specific factors that can change the answer
State law sets the floor, but these local conditions often decide whether a specific parcel works.
Very High Fire Hazard Severity Zone (VHFHSZ)
ADUs must comply with fire code; sprinklers required if primary dwelling requires them.
Historic District
ADUs in historic districts are exempt from parking requirements.
Paso Robles sets a 1,200 sq ft local maximum for detached and attached ADUs on single-family lots, requires 6 ft separation from other structures, and applies variable front setbacks by zone. Multifamily lots have unique caps on detached ADUs and parking is not required in historic districts or near transit.
Frequently asked questions
Can I build an ADU in Paso Robles?
Yes. California's statewide ADU law requires Paso Robles 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 Paso Robles?
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 Paso Robles?
Side and rear setbacks are limited to 4 ft. 15 ft (20 ft to garage door); R-1 B-3/B-4/B-5: 20 ft; R-2/R-3/R-4/R-5: 25 ft from arterial street.
Is parking required for an ADU in Paso Robles?
Up to 1 space. 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 Paso Robles?
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 Paso Robles?
Owner-occupancy: only for a jadu. ADUs under 750 sq ft are also exempt from impact fees.
Sources
- Paso Robles Municipal Code Chapter 21.58 (Ord. No. 1151 N.S., § 4(Exh. A), adopted Nov. 19, 2024)
- §21.58.040(A)3-4
- §21.58.060(A)
- §21.58.060(A)3, (B)
- §21.58.060(C)
- §21.58.060(D)
- §21.58.060(H)
- §21.58.060(H)3
- §21.58.040(C), §21.58.050(G)
- §21.58.070, §21.58.040(B)
- §21.58.050(C)
- 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)
- Cal. Gov. Code § 66311.5 (impact fees: none for an ADU ≤ 750 sq ft or JADU ≤ 500 sq ft)
Last updated November 19, 2024. This is an AI-assisted summary of Paso Robles'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 Paso Robles Planning before relying on it.
Will an ADU work on your Paso Robles lot?
Ask GoCodebook about your address and get the size, setback, parking and permit rules that actually apply to your parcel — with the exact citation.
Check my parcel free