The short answer
For ADU permits the City of Los Angeles issued from 2020 through 2023, the median time from issued permit to the city's final sign-off (certificate of occupancy) was about 13 months for garage conversions, about 11 months for junior ADUs, about 15 months for attached ADUs and about 16 months for detached ADUs. Add the permit itself (see how long permits take) for the whole timeline.
| Type | Median months, permit to sign-off | Signed off as finished | Permits |
|---|---|---|---|
| Garage conversion | 13 | 82% | 10,670 |
| Junior ADU (JADU) | 11 | 83% | 1,531 |
| Attached ADU | 15 | 82% | 2,759 |
| Detached ADU | 16 | 82% | 5,748 |
“Signed off as finished” counts every permit issued in those years, including ones that later expired or were cancelled. Months use permits with a recorded certificate of occupancy date.
By the year the permit was issued
| Median months to sign-off | 2020 | 2021 | 2022 | 2023 |
|---|---|---|---|---|
| Garage conversion | 12 | 13 | 13 | 12 |
| Junior ADU (JADU) | 11 | 13 | 12 | 10 |
| Attached ADU | 13 | 14 | 15 | 15 |
| Detached ADU | 15 | 16 | 16 | 15 |
Recent years only include projects already finished, so they can look faster than they will end up.
What happens after the permit
Once the permit is issued, the builder schedules inspections at each stage (foundation, framing, utilities, final). The city signs the unit off as finished with a certificate of occupancy after the final inspection; only then can it be lived in or rented. Garage conversions and junior ADUs reuse an existing structure, which is why they tend to finish sooner than a new detached building.
It depends on the neighborhood
Across the San Fernando Valley's Los Angeles neighborhoods (all ADU types), the quickest median builds were in Reseda (10 months), West Hills (11 months) and Winnetka (11 months); the longest were in Shadow Hills and Lake View Terrace (16 months), North Hollywood (15 months) and Valley Glen (14 months).
Other cities
From the permit and completion dates cities report to the state, for permits issued in the same years (2020 through 2023, except the incomplete years noted below).
Same-day “completions” (the permit date reported twice) are left out: 2 in Buena Park, 3 in Carlsbad, 2 in Culver City, 1 in Del Mar, 2 in Encinitas, 2 in Garden Grove, 1 in Glendale, 4 in La Habra, 2 in La Mesa, 1 in Laguna Beach, 1 in Lakewood, 4 in Long Beach, 1 in Newport Beach, 1 in Oceanside, 6 in Ojai, 1 in Pasadena, 1 in Poway, 1 in San Fernando, 1 in Santa Ana, 2 in Unincorporated Los Angeles County, 37 in Unincorporated Ventura County, 30 in Vista, 1 in Whittier and 10 in Yorba Linda.
Years with incomplete reports are left out: 2020 in Cypress, 2021 in Ojai and 2021 in Unincorporated Orange County.
Left out: Burbank, whose reports give the same date for the permit and the completion, so build time can't be measured.
Search your address on the map →