The honest ranges
Most of the ADUs we design and build range from $300,000 to $1.5 million. Garage conversions and junior ADUs, which reuse structure that already exists, can start around $200,000. These are wide ranges on purpose: an ADU is a complete small home, and its cost moves with the same forces as any home, including size, site, utilities, and finishes.
Every figure on this page is a range, not a quote. Each project carries its own site conditions, scope, and finishes, and the honest number for yours comes from a conversation, not a webpage.
ADU cost by type
These ranges come from ADU projects we have recently priced in Los Angeles. Every project is priced on its own site and scope.
| ADU type | Typical LA range |
|---|---|
| Garage conversion | From $200,000 |
| Attached ADU | From $300,000 |
| Detached ADU | $280,000 to $1,150,000 |
| Two-story ADU | From $400,000 |
Junior ADUs: what they are and what they cost
A junior ADU, or JADU, is a smaller unit of up to 500 square feet of interior living space created inside an existing single-family home, which can include an attached garage. It needs an efficiency kitchen and may share a bathroom with the main house; if it does, it needs its own exterior entrance and an interior door, and the owner must live on the property in either unit. LA records a deed restriction on JADUs, no parking is required, and a JADU of 500 square feet or less pays no impact fees.
Because a JADU reuses rooms that already exist, it is usually the lowest-cost way to add a unit. Garage conversions and junior ADUs start around $200,000 in our experience, depending on the condition of the space, plumbing runs, and finishes.
What drives ADU cost
Size and type come first. A junior ADU inside the existing house involves far less new structure than a detached two-bedroom unit. Site conditions come second: utility connections, grading, access for equipment, and hillside work can each move the number meaningfully. Finishes come third, and they are where you hold the most control, from clean and durable to fully bespoke.
Garage conversions often start around $200,000 because the structure, slab, and roof already exist. Detached units with full kitchens, laundry, and custom finishes occupy the upper end.
Why design-build protects your budget
The most expensive words in construction are we did not plan for that. In our design-build model, the builder helps create the plans, so constructability and cost are checked at the drawing stage rather than discovered on site. We talk candidly about budget at the first consultation, design to the number we agree on, and tell you before anything is drawn if a wish and a budget do not match.
Related: Guide to building an ADU in Los Angeles, ADU builder in Los Angeles.
Common questions
What is the cheapest way to add an ADU?
Usually a junior ADU or a garage conversion, because both work within structure that already exists. Garage conversions and junior ADUs in our experience can start around $200,000, with the final number depending on the specifics of the home.
Does the $300,000 to $1.5 million range include design and permits?
Our ranges reflect complete design-build projects. At your consultation we break down exactly what your project includes so there is nothing vague about the number you approve.
Can you design an ADU to a specific budget?
Yes. That is the core of how we work: we agree on a realistic number first, then design the unit to honor it.
How much does an ADU cost in Los Angeles?
Most of our ADUs range from $300,000 to $1.5 million, and garage conversions and junior ADUs start around $200,000. By type: garage conversions from $200,000, attached ADUs from $300,000, detached ADUs from $280,000 to $1,150,000, and two-story ADUs from $400,000. Size, site conditions, utilities, finishes, and permits set where your project lands.
HCD ADU Handbook (March 2026) | Gov. Code 66333 (JADUs)
Prices are ranges from projects we have priced, not quotes. Rules change and every lot is different; confirm the rules for your property before you design or build.