Complete 2026 cost breakdown: construction, permits, financing, and expected rental ROI.
Calculate your Los Angeles ADU cost →Building an ADU in Los Angeles costs between $150,000-$350,000 for new construction, with per-square-foot costs averaging $200-$400. These figures include design, permitting, site preparation, and construction. The most affordable option is a garage conversion at $80,000-$180,000, while prefab/modular ADUs fall in between at $100,000-$250,000.
| Cost Category | Estimated Range |
|---|---|
| Architectural Plans | $3,000 – $15,000 |
| Permits & Fees | $4,000-$15,000 depending on size and type (plus 10% General Plan Maintenance Surcharge on permit fees as of June 9, 2026) |
| Impact Fees | Waived for units under 750 sq ft (state law) |
| 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 Los Angeles — no obligation.
Get Los Angeles builder quotes →Permit fees in Los Angeles are $4,000-$15,000 depending on size and type (plus 10% General Plan Maintenance Surcharge on permit fees as of June 9, 2026). The review timeline is 60-day ministerial review (state-mandated), with plan check: 2-4 weeks (expedited review available). Impact fees are Waived for units under 750 sq ft (state law). Pre-approved plans: Yes — LA has a Standard Plan Program with pre-approved designs.
| 1-Bedroom Rent | $1,800-$2,500/month |
| 2-Bedroom Rent | $2,200-$3,200/month |
| Annual Rental Income (est.) | $25,800/year |
| Payback Period (est.) | 9.7 years |
| Short-Term Rental | Restricted — STR rules apply; host must be primary resident |
| Overall ROI Estimate | 6-10% annual return |
A typical ADU in Los Angeles generates approximately $25,800 per year in rental income based on average 1-bedroom rents. At an average construction cost of $250,000, the estimated payback period is 9.7 years — before accounting for the resale value the ADU adds, which an appraiser determines from comparable sales in Los Angeles 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 Los Angeles: $80,000-$180,000.
2. Prefab/modular ADUs offer predictable pricing and faster timelines. Average: $100,000-$250,000.
3. Pre-approved plans — available in Los Angeles, 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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