How much does an ADU cost in Los Angeles in 2026?
A detached ADU in Los Angeles costs roughly $250 to $450 per square foot all-in, which puts a typical 600–800 sq ft unit at $150,000 to $350,000. A garage conversion is cheaper — usually $100,000 to $200,000, because the shell already exists. Add 8 to 14 months from first drawing to final inspection. The two costs people forget are utility connections and site work, and together they can add $20,000 to $60,000.
The cost, honestly
| Type | Typical all-in range |
|---|---|
| Garage conversion (400–500 sq ft) | $100k – $200k |
| Attached ADU (500–700 sq ft) | $150k – $300k |
| Detached new-build (600–800 sq ft) | $200k – $350k |
| Detached, high-end or two-story | $350k – $500k+ |
These are typical Los Angeles market ranges as of 2026, not a quote. Your number depends on the site, the soil, how far the unit sits from the main house, and what your panel can carry.
The costs people leave out of their budget
Utility connections. Water, sewer, and electrical have to reach the ADU. If your main panel is 100 amps — common in older Burbank, Glendale, and Valley houses — you are upgrading it. Sewer lateral work and trenching across a yard adds up fast. Together: $20,000–$60,000.
Site work. Grading, drainage, a driveway or path, tree removal or protection, and fire-department access. On a flat, open lot this is minor. On a hillside lot, it is not.
Impact and school fees. Under state law, ADUs under 750 sq ft are exempt from impact fees — which is exactly why so many ADUs come in at 749 square feet. Above that, fees are proportional and real.
Design and engineering. $10,000–$25,000 for drawings, structural engineering, and Title 24 energy compliance.
What California law lets you do
State law has been steadily forcing cities to say yes. In broad terms: most single-family lots may add an ADU, cities must act on a complete application within 60 days, owner-occupancy requirements have been rolled back, and parking cannot be required if the property is within half a mile of transit. Setbacks are limited to four feet from the side and rear.
Local rules still vary, and they change. Before you fall in love with a floor plan, confirm the current rules with your city's planning department — the answer in Burbank is not automatically the answer in Los Angeles.
Where projects go wrong
Almost always the same two places. The first is the panel — the electrical service turns out to be undersized, and the upgrade was never in the budget. The second is the sewer — the lateral is old clay pipe, and it fails when it gets touched.
Both are knowable before you start. A contractor who walks the site, opens the panel, and asks about the sewer line is doing you a favor, even if the number that comes back is higher than you hoped.
Get the sequence right
Feasibility and site check → design → structural and Title 24 → plan check → permit → build → inspections → final. Skipping straight to "how much per square foot" is how people end up $60,000 over.
DN Builders Group Inc is a licensed, bonded general contractor based in Burbank (CA Lic. #1139710). See our home additions & ADUs page or request a walkthrough. Figures are typical 2026 Los Angeles market ranges, not a quote, and this is general information rather than legal or financial advice.
Questions
Is a garage conversion really that much cheaper than building new?
Usually yes — the foundation, walls, and roof already exist, which is a large share of the cost of new construction. But it is not free money. Most garages need a new slab or slab repair, real insulation, egress windows, a full electrical panel upgrade, and plumbing run from the house. Budget $100,000 to $200,000, and expect surprises if the garage is old.
How long does an ADU take in Los Angeles?
Plan on 8 to 14 months end to end. Design and engineering is 1–3 months, plan check and permits 2–5 months depending on the jurisdiction, and construction 5–8 months. State law caps ADU permit review at 60 days once the application is complete — the words "once complete" are doing a lot of work in that sentence.
Will an ADU actually pay for itself?
It depends on rent versus the cost of your money, and nobody can promise you a return. What we can tell you is what people build them for — rental income, housing a family member, or adding square footage that counts at resale. Run the numbers with your accountant before you run them with your contractor.