Everything homeowners ask about building an ADU in Long Beach — answered with 2026 data.
Yes, ADUs are allowed in Rewrite — the city does not administer ADUs by zone at all. Because there is no local ordinance, eligibility turns on LOT TYPE, not zoning district: a 'single-family dwelling lot' has one or more detached single-family dwellings and no multi-family dwelling; a 'multi-family' lot has two or more principal dwelling units in one building or attached buildings. Both existing and proposed principal units count. Mixed lots get the SFD menu for the SFD and the MFD menu for the MFD, and the two cannot be cross-applied. Our R-1/R-2/R-3/R-4 list is not sourced to anything the city publishes and should not be presented as a Long Beach fact. in Long Beach, CA. The maximum size for a detached ADU is 800 sq ft (detached new construction, single-family lot). STRICTER than the 850/1,000 sq ft floor in Gov. Code 66321(b)(2) — flag as arguably preempted, but this is the city's published operative limit. City's stated basis is Gov. Code 66323(a)(2)(A), the by-right pathway, which Long Beach administers because it has no local ADU ordinance. On multi-family lots the city imposes NO size limit on detached ADUs.. Attached ADUs can be up to 50% of the size of the primary dwelling or 800 sq ft, whichever is MORE. MORE GENEROUS than our page: there is no 1,200 sq ft ceiling, so on a 3,000 sq ft house an attached ADU may reach 1,500 sq ft. The limit applies only to the added floor area, not to any converted area of the existing house. An attached ADU built in conjunction with a proposed new single-family dwelling has NO size limit.. Long Beach has an ADU-friendliness score of 8/10. Check our full Long Beach ADU rules page for complete zoning details.
ADU construction in Long Beach typically costs $120,000-$280,000. The cost per square foot averages $180-$330. Garage conversions are more affordable at $70,000-$150,000, while prefab ADUs cost $90,000-$220,000. Permit fees add Replace the guessed range with the city's published figures. Long Beach's own guidance: 'For most construction projects, you could expect to spend about 2% of your building costs on plan checks, permits, inspections and other agency fees.' Published components (Building Permit & Plan Check Fees, effective 5/20/2026): Building Permit fee by valuation — $1,264 for the first $100,000 plus $6 per additional $1,000 in the $100,001-$1,000,000 band; Combination Building Permit (Group R-3, includes electrical, plumbing, mechanical) = 150% of the Building Permit fee, minimum $164; Combination Plan Check = 85% of the Building Permit fee, minimum $154; Zoning Plan Check = 0.5% of project valuation for valuations up to $750,000, minimum $310, capped at 95% of the building standard plan check fee; NPDES permit = $2 per $1,000 of valuation with plan check at 75% of that; Expedited plan check = 2x standard. Add a $115.00 processing fee to EACH plan check and permit application, plus a 6% Technology Surcharge and a 6% General Plan Surcharge on all applicable fees. Worked from those published formulas, a $150,000-valuation ADU lands near $5,800 in permit and plan-check fees before impact fees — I am labelling that figure as DERIVED from the published schedule, not published by the city. to your budget. See our detailed Long Beach ADU cost guide.
Detached ADUs in Long Beach can be up to 800 sq ft. Attached ADUs are limited to 50% of the size of the primary dwelling or 800 sq ft, whichever is MORE. MORE GENEROUS than our page: there is no 1,200 sq ft ceiling, so on a 3,000 sq ft house an attached ADU may reach 1,500 sq ft. The limit applies only to the added floor area, not to any converted area of the existing house. An attached ADU built in conjunction with a proposed new single-family dwelling has NO size limit.. Junior ADUs (JADUs) have a cap of 500 sq ft. ADOPTS the state figure. Conversion only, of a portion of the existing primary dwelling or attached garage; no addition is permitted for a JADU. No JADU is allowed on any lot containing a multi-family dwelling, regardless of whether a single-family dwelling is also present — that exclusion is worth stating on the page.. Maximum height is ADOPTS the state tiers, with two city-specific refinements our page misses. Detached: 16 ft default; 18 ft within one-half mile walking distance of a major transit stop or high-quality transit corridor; 18 ft where an existing multi-story multi-family dwelling is on site; 18 ft plus up to 2 ft to match an existing sloped roof on the primary dwelling. Attached new construction (single-family lots only): '25 feet/2 stories, or zoning height limit, whichever is less' — the zoning-limit cap is a real constraint our page omits. Conversions simply maintain existing building height. Height is measured per LBMC 21.15.1330 and 21.15.1335 (midpoint of sloped roof), which are Long Beach definitions, not state ones.. You are allowed up to MORE GENEROUS than our page, materially. Single-family lot: one conversion ADU AND one detached new-construction ADU, plus one JADU — up to three additional units, not two. Multi-family lot with an existing building: up to 8 detached ADUs, or the number of existing permitted units, whichever is less; plus attached conversion ADUs at 1 unit or 25% of existing permitted units, whichever is MORE. Proposed on a qualifying lot.
Rear setback: 4 ft for new construction — ADOPTS the state minimum on its face, but with a Long Beach measurement rule that is effectively MORE GENEROUS: 'The rear setback shall be measured to centerline of adjacent alley where such exists.' On Long Beach's many alley-served lots this lets the structure sit substantially closer to the rear property line than a naive 4 ft reading suggests. Conversions maintain the existing setback, subject to fire and life safety.. Side setback: '4 feet or per zoning district, whichever is less.' MORE GENEROUS than our flat 4 ft — where the underlying zone requires a narrower side yard, the smaller number governs, so a homeowner in a zone with a 3 ft side yard builds to 3 ft. Our current value tells them to give up buildable width they do not have to give up.. Front setback: Per zoning district, BUT with an express encroachment allowance that is MORE GENEROUS than our page: if there is no other way to fit an ADU of up to 800 sq ft on the lot, the ADU may encroach into the required front yard setback, subject to Building and Fire code restrictions. This is the escape hatch for narrow or shallow Long Beach lots and is worth calling out.. Note that garage conversions may be exempt from setback requirements if the existing structure is already within the setback area.
MORE GENEROUS than our page — the city publishes eight exemptions, including one that is purely local. No parking is required for an ADU: within one-half mile walking distance of any transit stop; in a historic district; converted from part of the primary dwelling or an accessory building; where on-street permits are required on the adjacent street but not offered to the ADU occupant; within one-half mile of a car share vehicle; submitted with an application for a new SFD or MFD where any of the above apply; for any JADU; or located within the Parking Exempt Area established by LBMC 21.41.175. The Parking Exempt Area is a Long Beach-specific mapped geography with its own published map and is not a state exemption — our page should link it alongside the ADU Parking Exemption Map.. Many cities and states have been relaxing ADU parking requirements in recent years. In California, no additional parking is required for ADUs near transit.
ADOPTS state law. Not required for an ADU. For a JADU, owner occupancy of either the single-family dwelling or the JADU is required ONLY if the JADU shares a bathroom with the primary dwelling — matching Gov. Code 66333(b) and AB 1154. Our 'Not required' is right for ADUs but silently wrong for the shared-bathroom JADU case; the value should be split.. Note that owner-occupancy rules vary by state law — California and several other states have eliminated this requirement for standard ADUs.
The ADU permit review timeline in Long Beach is typically 60 days; often 30-45 in practice. Plan check: Efficient review process. Pre-approved plans availability: Yes, but add the caveat the city itself publishes: the Pre-Approved Accessory Dwelling Unit Program (PAADU) 'is currently undergoing changes, and updates will be provided over the coming months on this webpage.' What is verified: PAADU plans and permit applications may be approved Over-The-Counter at the Permit Center with Planning and Building & Safety assistance, and a building permit can be issued the same day. PAADUs must still comply with city ADU regulations, and the city directs owners in a coastal zone or historic district to submit a Planning and Zoning Inquiry Form first. Contact PlanCheck.Counter@longbeach.gov. Our unqualified 'Yes' risks sending a homeowner to a program that is mid-overhaul..
Average ADU rental income in Long Beach: 1-bedroom units rent for $1,500-$2,100/month, 2-bedroom units for $1,900-$2,700/month. Short-term rentals: Allowed with business license; STR regulations apply. Expected ROI: 7-11% annual return.
The minimum lot size for an ADU in Long Beach is No minimum. Correct, and stronger than our page states: because Long Beach has no ADU ordinance, no local lot standards attach at all. The bulletin expressly disapplies lot coverage, open space and floor area ratio, and also open space standards for the primary dwelling, landscaping, street trees and permeability standards. Note the bulletin does not use the words 'minimum lot size' — this follows from the city applying state law only.. This applies to detached ADUs — garage conversions and JADUs may have different or no lot size requirements.
Garage conversions are one of the most popular and affordable ADU options. In Long Beach, a garage conversion typically costs $70,000-$150,000. The key advantages are lower cost (no foundation work), potential setback exemptions, and faster permitting. Read our complete garage conversion guide.
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