Complete 2026 cost breakdown: construction, permits, financing, and expected rental ROI.
Calculate your Long Beach ADU cost →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.
| Cost Category | Estimated Range |
|---|---|
| Architectural Plans | $3,000 – $15,000 |
| Permits & Fees | $3,000-$10,000 |
| Impact Fees | Waived for units under 750 sq ft |
| Site Prep & Foundation | $10,000 – $35,000 |
| Framing & Structure | $15,000 – $45,000 |
| Plumbing | $8,000 – $20,000 |
| Electrical | $5,000 – $15,000 |
| HVAC | $3,000 – $8,000 |
| Interior Finishes | $15,000 – $40,000 |
Quotes for the same ADU commonly vary 20–40% between builders. Get up to 3 free quotes from ADU builders serving Long Beach — no obligation.
Get Long Beach builder quotes →Permit fees in Long Beach are $3,000-$10,000. The review timeline is 60 days; often 30-45 in practice, with plan check: Efficient review process. Impact fees are Waived for units under 750 sq ft. Pre-approved plans: Yes — city has pre-approved ADU plans.
| 1-Bedroom Rent | $1,500-$2,100/month |
| 2-Bedroom Rent | $1,900-$2,700/month |
| Annual Rental Income (est.) | $21,600/year |
| Payback Period (est.) | 9.3 years |
| Short-Term Rental | Allowed with business license; STR regulations apply |
| Overall ROI Estimate | 7-11% annual return |
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).
1. Garage conversions save 40-60% vs new construction since the shell already exists. Average cost in Long Beach: $70,000-$150,000.
2. Prefab/modular ADUs offer predictable pricing and faster timelines. Average: $90,000-$220,000.
3. Pre-approved plans — available in Long Beach, which can save $3,000-$10,000 in design costs and 2-3 months in review time.
4. State grants — California's CalHFA ADU grant (up to $40K) is currently paused; check calhfa.ca.gov/adu for status and your state for active programs.
5. Get multiple bids — ADU contractor pricing varies 20-40% for the same project. We recommend getting at least 3 quotes.
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