California ADU rules · Orange County
Can I Build an ADU in Buena Park?
Yes — you can build an ADU in Buena Park. California's statewide ADU law requires every city, including Buena Park, 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 ruleup to 2 detached ADUs on lots with a proposed multifamily dwelling; up to 8 detached ADUs on lots with an existing multifamily dwelling (not to exceed number of existing units); conversion ADUs: up to 25% of existing units (at least 1); JADUs not permitted in multifamily zones
JADUs are not allowed in multifamily zones; detached ADU cap is 8 or number of existing units, whichever is less.
Junior ADU (JADU)
Local ruleAllowed
JADUs allowed only on single-family lots.
Size & height
Max detached ADU size
Local rule1,000 sq ft
Detached ADUs: 850 sq ft (studio/1-bed), 1,000 sq ft (2+ bedrooms); conversion ADUs not subject to these limits.
Max attached ADU size
Local rule850 sq ft (1-bedroom), 1,000 sq ft (2+ bedrooms)
Attached ADUs have same max as detached.
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 rule20 ft
Detached ADU: 16 ft standard; 20 ft if within 1/2 mile of major transit or on multifamily/mixed-use lot with multistory dwelling. Attached ADU: up to 30 ft or height of existing two-story primary, whichever is lower.
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 ruleADU may be built in front yard setback if physically infeasible to build elsewhere while maintaining side/rear setbacks
Allows ADU in front setback if no feasible alternative.
Separation from main house
CA state lawNone required
No statewide separation requirement between the ADU and the primary dwelling.
Parking
Parking required
Local ruleUp to 1 space
1 space per ADU; multiple exemptions apply.
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 main dwelling when garage/carport/covered parking is converted to ADU.
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 must occupy main dwelling, ADU, or JADU if a JADU is present; no owner-occupancy for ADU alone.
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, Demolition permit (if replacing detached garage)
Demolition permit required only if replacing a detached garage; issued concurrently.
Buena Park-specific factors that can change the answer
State law sets the floor, but these local conditions often decide whether a specific parcel works.
Historic District
No parking required for ADU in historic district; garage demolition in historic district may require additional notice.
Buena Park caps new detached and attached ADUs at 1,000 sq ft (2+ bedrooms) and 850 sq ft (1-bedroom); JADUs are not allowed in multifamily zones. ADUs may be built in the front setback if no feasible alternative exists.
Frequently asked questions
Can I build an ADU in Buena Park?
Yes. California's statewide ADU law requires Buena Park 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 Buena Park?
A detached ADU of at least 1,000 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 Buena Park?
Side and rear setbacks are limited to 4 ft. ADU may be built in front yard setback if physically infeasible to build elsewhere while maintaining side/rear setbacks.
Is parking required for an ADU in Buena Park?
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 Buena Park?
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 Buena Park?
Owner-occupancy: only for a jadu. ADUs under 750 sq ft are also exempt from impact fees.
Sources
- Buena Park Municipal Code, Chapter 19.348 (Ord. 1754, 6/24/2025)
- Buena Park Municipal Code, § 19.348.010
- 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 § 66321 (size minimums & height)
- Cal. Gov. Code § 66333 (junior ADUs)
- 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 2026-06-25. This is an AI-assisted summary of Buena Park'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 Buena Park Planning before relying on it.
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