Buena Park ADU rules

Maximum size

A new attached or detached ADU may have up to 850 sq ft of livable space with up to one bedroom, or 1,000 sq ft with more than one bedroom. The new detached ADU allowed alongside a converted ADU and a JADU on a single-family lot is limited to 800 sq ft; a second or larger detached ADU follows the 850 and 1,000 sq ft limits. An ADU converted from existing space may add up to 150 sq ft for entry and exit. Every ADU and JADU must be at least 150 sq ft.

Source: Buena Park Municipal Code § 19.348.010 Accessory Dwelling Units and Junior Accessory Dwelling Units, as amended by Ordinance 1770 (eCode360), § 19.348.010(C)(6)(a), (C)(6)(c), (C)(7), accessed 2026-11-03.

Setbacks

A new ADU needs at least 4 ft from the side and rear lot lines. A conversion of existing space, or a rebuild in the same place and size, may keep the existing setbacks. The zone's front setback applies; an ADU over 800 sq ft may be built in the front setback if it cannot fit elsewhere on the lot with 4 ft side and rear setbacks. For the added ADU type, second-story balconies need 5 ft from side and rear lines, and outside stairs may not face the street. State law does not let a front setback block an 800 sq ft ADU with 4 ft side and rear setbacks.

Source: Buena Park Municipal Code § 19.348.010 Accessory Dwelling Units and Junior Accessory Dwelling Units, as amended by Ordinance 1770 (eCode360), § 19.348.010(C)(4), (C)(5), accessed 2026-11-03.

Local ADU rules

Buena Park's ADU rules are in Municipal Code section 19.348.010, last amended by Ordinance 1770 (adopted September 8, 2026, in effect 30 days later; shown on eCode360 as a new law not yet merged into the code text). ADU and JADU applications that meet the rules are acted on ministerially, without a hearing, within 60 days. An application may not be denied because of nonconforming conditions or unpermitted structures that do not threaten health and safety.

Source: Buena Park Municipal Code § 19.348.010 Accessory Dwelling Units and Junior Accessory Dwelling Units, as amended by Ordinance 1770 (eCode360), § 19.348.010(B), accessed 2026-11-03.

Number and types of ADUs

On a residential or mixed-use lot with a single-family home, any of these are allowed: one ADU inside the home or an accessory structure (up to 150 sq ft added for entry and exit), one new detached ADU of up to 800 sq ft, and one JADU. One more ADU is allowed on top of those: a new detached ADU (built in addition to the 800 sq ft unit, or larger than 800 sq ft), a new attached ADU, or a converted ADU. On a lot with an existing multifamily building: converted ADUs in non-livable space (at least one, up to 25% of the existing units) and up to 8 new detached ADUs, not more than the number of existing units. On a lot with a proposed multifamily building: up to 2 detached ADUs. JADUs are not allowed in multifamily buildings.

Source: Buena Park Municipal Code § 19.348.010 Accessory Dwelling Units and Junior Accessory Dwelling Units, as amended by Ordinance 1770 (eCode360), § 19.348.010(C)(1), (C)(6), accessed 2026-11-03.

Height

An ADU may be 16 ft. A detached ADU may be 20 ft within a half mile of a major transit stop or high-quality transit corridor, or on a lot with a multistory multifamily building. An ADU attached to a single-family home may be two stories, up to 30 ft or the height of an existing two-story home, whichever is lower.

Source: Buena Park Municipal Code § 19.348.010 Accessory Dwelling Units and Junior Accessory Dwelling Units, as amended by Ordinance 1770 (eCode360), § 19.348.010(C)(3), accessed 2026-11-03.

Parking

Parking is required only for the added ADU type (a second or larger detached ADU, a new attached ADU, or the added converted ADU): one space per ADU, which may be tandem on a driveway. No space is needed within a half mile walk of public transit, in a historic district, for an ADU inside the home or an accessory building, where on-street permits are required but not offered, within one block of a car share vehicle, or when the ADU is filed with a new home or multifamily building. Garage or carport spaces removed for an ADU do not have to be replaced, and a JADU needs no parking.

Source: Buena Park Municipal Code § 19.348.010 Accessory Dwelling Units and Junior Accessory Dwelling Units, as amended by Ordinance 1770 (eCode360), § 19.348.010(C)(8)-(9), accessed 2026-11-03.

Junior ADUs

One JADU of up to 500 sq ft of livable space is allowed inside a single-family home (an attached garage counts), and may add up to 150 sq ft for entry and exit. It needs its own entrance and an efficiency kitchen. The owner must live on the property only if the JADU shares a bathroom with the home. A recorded deed restriction is required, and the JADU or main home may not be rented for less than 30 days.

Source: Buena Park Municipal Code § 19.348.010 Accessory Dwelling Units and Junior Accessory Dwelling Units, as amended by Ordinance 1770 (eCode360), § 19.348.010(C)(6)(a)(iii), (C)(7)(c), (C)(20), accessed 2026-11-03.

Privacy and garage conversions

For the added ADU type, second-story windows and glass doors must protect neighbors' privacy by one or more of: sills at least 6 ft above the floor, opaque or obscured glass, or windows that do not face side or rear lot lines (landscaping may be added to these). When a garage is converted to an ADU, a garage door visible from the street must be replaced with a wall, windows or a door. Manufactured homes need skirting.

Source: Buena Park Municipal Code § 19.348.010 Accessory Dwelling Units and Junior Accessory Dwelling Units, as amended by Ordinance 1770 (eCode360), § 19.348.010(C)(16), accessed 2026-11-03.

Fees, utilities and renting

ADUs over 750 sq ft of livable space pay park fees and other impact fees in proportion to the main home's size. Utilities may be metered with the main home. Fire sprinklers are not needed if the main home does not need them. ADUs must use the main home's driveway unless there is an alley, a corner-lot side-street driveway, or a second driveway that costs no street parking. ADUs may not be sold separately and may not be rented for less than 30 days.

Source: Buena Park Municipal Code § 19.348.010 Accessory Dwelling Units and Junior Accessory Dwelling Units, as amended by Ordinance 1770 (eCode360), § 19.348.010(C)(10), (C)(12), (C)(14)-(15), (C)(17)-(18), accessed 2026-11-03.

State housing department (HCD) review

On May 28, 2025, HCD found that Buena Park's earlier ADU ordinance (Ordinance 1736, March 2024) did not comply with state ADU law on several points: detached ADU limits on multifamily lots, legalizing unpermitted units, outdated code references, ADUs on lots with nonconforming homes, a front setback condition, and limits on combining ADU types. The City had until June 26, 2025 to respond. It adopted Ordinance 1770 in September 2026, which changed these sections. Confirm the current rules with the City of Buena Park.

Source: HCD ordinance review letter, City of Buena Park, Letter of May 28, 2025, accessed 2026-11-03.