How Much Does an ADU Cost in Long Beach, CA?

Construction Cost Breakdown

Building an ADU in Long Beach costs between $120,000-$280,000 for new construction, with per-square-foot costs averaging $180-$330. These figures include design, permitting, site preparation, and construction. The most affordable option is a garage conversion at $70,000-$150,000, while prefab/modular ADUs fall in between at $90,000-$220,000.

Permit Costs & Timeline

Permit fees in Long Beach are 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.. The review timeline is 60 days; often 30-45 in practice, with plan check: Efficient review process. Impact fees are Keep the state exemption sentence, but add the city's actual published ADU line items — Long Beach breaks out ADUs separately in its Development Impact Fees schedule (effective 10/1/2025): Fire Facilities Impact Fee, ADU $241.74 per dwelling unit (vs $496 single-family); Parks & Recreation Facilities Impact Fee, Accessory Unit incl. ADU $1,781.39 per dwelling unit (vs $4,613.04 single-family); Police Facilities Impact Fee, ADU $342.86 per dwelling unit (vs $703 single-family). That is $2,366.00 in city impact fees for an ADU over the 750 sq ft state threshold. Transportation Improvement Fee has its own tiers: Accessory up to 220 sq ft $236.25, Secondary up to 640 sq ft $663.75. Separately, a Sewer Capacity Fee of $144.34 applies (raised from $139.52 on 10/1/2025) — a capacity charge, which is generally treated as outside the ADU impact-fee exemption, but I did not verify that treatment for Long Beach. School fees are levied by LBUSD, not the city, at lbschools.net/developerfees.. Pre-approved plans: 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..

Rental Income & ROI

A typical ADU in Long Beach generates approximately $21,600 per year in rental income based on average 1-bedroom rents. At an average construction cost of $200,000, the estimated payback period is 9.3 years — before accounting for the resale value the ADU adds, which an appraiser determines from comparable sales in Long Beach and varies by market (often less than build cost).

Ways to Reduce ADU Costs in Long Beach