How Much Does an ADU Cost in Los Angeles? (2026 Price Guide)
In 2026, an ADU in Los Angeles typically costs $180,000 to $400,000+, or about $250 to $400 per square foot. Here is a full cost breakdown by ADU type, including plans and permits.
Get a Free QuoteADU cost by type in Los Angeles (2026)
What you pay depends most on the type of ADU and your lot. Here are typical all-in construction ranges for LA County:
| ADU type | Typical size | Estimated build cost | Cost per sq ft |
|---|---|---|---|
| Garage conversion | 400–600 sq ft | $100,000–$225,000 | $150–$250 |
| Junior ADU (JADU) | up to 500 sq ft | $90,000–$180,000 | $180–$300 |
| Attached ADU | 400–1,000 sq ft | $150,000–$350,000 | $250–$375 |
| Detached ADU | 600–1,200 sq ft | $200,000–$400,000+ | $250–$400 |
Ranges reflect 2026 Los Angeles pricing and vary with finishes, site conditions, and city. Westside and hillside lots can exceed $500 per sq ft. Build-cost totals are all-in (design, permits, site work, and construction), so they run higher than size multiplied by the construction-only rate.
What goes into the cost?
An ADU budget is more than construction. The main line items:
- Architectural design & plans: $8,000–$20,000 for a custom set, and far less with a pre-designed plan set.
- Permit & city fees: roughly $5,000–$25,000, depending on the city — LA County has 88 cities, each with its own fee schedule.
- Construction: the largest cost, driven by size, finishes, and site work.
- Utilities & site work: sewer, electrical (an LADWP upgrade can add time and cost), grading, and foundations.
Plan-set cost vs. total build cost
These are two different numbers, and mixing them up is the most common budgeting mistake:
- Plan set — the permit-ready drawings you submit to the city. Jayzar pre-designed ADU plan sets run $7,900 to $16,900.
- Total build — the finished, move-in-ready ADU, built by a contractor such as JSN Construction, in the ranges above.
Buying a permit-ready plan set first lets you get an accurate construction bid and move through plan-check faster.
How to lower your ADU cost
- Start with a pre-designed, permit-ready plan set instead of a full custom design.
- Choose a garage conversion — it reuses an existing structure and is the cheapest path.
- Keep the footprint simple (single-story, rectangular) to reduce structural cost.
- Avoid relocating utilities where possible.
Frequently asked questions
How much does an ADU cost in Los Angeles?
Most ADUs in Los Angeles cost $180,000 to $400,000+ to build in 2026, or roughly $250–$400 per square foot. Garage conversions are cheaper at $100,000–$225,000.
What is the cheapest type of ADU to build?
A garage conversion is usually the cheapest ADU because it reuses an existing structure, typically $100,000–$225,000, or about $150–$250 per square foot.
How much do ADU plans cost?
A permit-ready plan set typically costs $8,000–$20,000 custom. Jayzar pre-designed ADU plan sets start at $7,900.
Does the ADU cost include permits?
No. City permit and agency fees (about $5,000–$25,000) are paid to your city and are separate from construction and plan-set costs.
Ready to start your ADU project?
Browse our permit-ready plan sets or request a free quote and our team will map out the plans, permits, and build with you.
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