Who we are
SoCal ADU Tracker is independent: we aren't a builder, a real-estate brokerage or a lender. Builders can pay for a clearly labeled featured listing; that never changes the data. We publish public records so homeowners can see what's actually being built near them.
Sources
- City of Los Angeles: Department of Building and Safety permits from the city's open-data portal, 2020 onward, limited to permits that create an ADU or junior ADU. The city publishes them about weekly.
- City of San Diego: Development Services Department permits from the city's open-data portal (public domain), 2018 onward, limited to building permits that create an ADU or junior ADU. The city publishes them daily.
- Other cities, the counties' unincorporated areas, and Los Angeles before 2020: the Housing Element Annual Progress Reports every city and county files with the state (California Department of Housing and Community Development), published once a year.
- We refresh the data about monthly. Every page says how current its data is.
What we count
- An ADU permit is counted once, in the year its building permit was issued. State reports place a project in its completion year when no permit date was reported.
- Projects approved without a building permit yet, and permits that expired or were cancelled, aren't counted in the totals; area pages show how many there are.
- Los Angeles neighborhood pages use the Neighborhood Council area recorded on each permit; San Diego neighborhood pages use the community planning area each permit's location falls in. Neither may match every local definition of a neighborhood. A neighborhood gets a page once it has at least 20 counted permits. Permits in Brentwood (90049) and Pacific Palisades (90272, 90402) record no Neighborhood Council, so those pages count permits by ZIP code.
ADU types
Los Angeles and San Diego permits don't have a type field, so we classify each one as a detached ADU, attached ADU, garage conversion or junior ADU from its description. Some permits can't be classified, and some will be wrong. The state reports don't record the type at all.
Permit times
Permit time runs from the application date to the day the permit was issued, so it includes plan-check corrections and resubmittals, not just the city's review. We show medians and the middle half, only when at least 10 permits have both dates, and leave out applications open more than 3 years. Some cities report their planning application date, so their times include planning review; their pages say so.
Costs
Costs are the values owners declared on Los Angeles and San Diego permits (single-ADU permits only). Declared values usually leave out design, fees and site work, so they understate what ADUs cost. The cost estimator explains the published research it uses for real costs.
Gaps in the data
Some cities' state reports are incomplete for some years. We mark those years, call them incomplete rather than zero, and don't compute changes across them. Some cities report dates we can't time permits from, and a few small cities aren't covered yet:
- Anaheim reported the building-permit date as the application date for most of its ADUs from 2020 to 2025, so approval times for those years can't be measured from the state reports and are left out.
- Cypress reported far fewer ADUs for 2019, 2020 and 2024 than for the years around them; those years likely understate permit activity.
- Hidden Hills reported no ADUs for 2024.
- Huntington Beach's state reports include no ADUs for 2018.
- Laguna Beach reported the building-permit date as the application date for most of its ADUs in 2023 and 2024, so approval times for those years can't be measured from the state reports and are left out.
- Laguna Hills' state reports include no ADUs for 2018 or 2023.
- Lancaster's state reports include almost no ADU permits before 2020 (a few carried in by later reports); 2018 and 2019 counts are incomplete.
- Mission Viejo's state reports include no ADUs for 2018 or 2019.
- National City's state reports include no ADUs for 2018.
- National City reported the building-permit date as the application date for most of its ADUs in 2019, 2020 and 2023, so approval times for those years can't be measured from the state reports and are left out.
- Ojai reported far fewer ADUs for 2021 than for the years around it, and for 2024 mostly completed projects (counted in their completion year); those years likely understate permit activity.
- Santa Paula reported no ADU building-permit dates. Its 2022 figures count completed projects; for 2021, 2023 and 2024 it reported only approvals, which are listed separately. Counts likely understate activity.
- Simi Valley reported no ADU building-permit dates for 2019 and, for 2020–2024, appears to have reported only completed projects; those are counted in their completion year. Yearly counts likely understate permit activity.
- Tustin reported the building-permit date as the application date for most of its ADUs in 2021 and 2024, so approval times for those years can't be measured from the state reports and are left out.
- Unincorporated Orange County reported far fewer ADUs for 2021 than for the years around it; that year likely understates permit activity.
- Ventura reported no ADU building-permit dates for 2023; that year's bar counts completions only and is likely incomplete.
- Villa Park's state reports include no ADUs for 2022.
- Vista's state reports include no ADUs for 2018.
- Orange County: Irvine, Seal Beach, La Palma, Los Alamitos, Rancho Santa Margarita and Aliso Viejo aren't covered yet; each has reported fewer than 20 ADU permits to the state.
Laws and guides
Legal points in our guides summarize the statutes, the state's ADU Handbook and each agency's published rules, with links, and each guide shows the date we last reviewed it. They're general information, not legal advice.
Corrections
Spotted an error? Email [email protected] with the page and what looks wrong, and we'll check it against the source.