In short
- 65 ADU permits since 2018.
- 13 in 2025.
About this data
- Source: California HCD Housing Element Annual Progress Reports. The state data does not say whether an ADU is detached, attached, a garage conversion or a JADU, so most records show as 'unknown'. Permit valuations are not published in this source. Timelines use the application date the city reported to the state, matched to the permit where possible; some cities report their planning application date, so timelines can include planning review. Each project is counted once, in its building-permit year (or completion year when no permit date was reported).
Permits by year
Permits by year and type (table)
| Year | All ADU permits | Garage conversions | Detached |
|---|---|---|---|
| 2018 | 2 | — | — |
| 2019 | 1 | — | — |
| 2020 | 5 | 0 | 0 |
| 2021 | 11 | 0 | 0 |
| 2022 | 11 | 0 | 0 |
| 2023 | 11 | 0 | 0 |
| 2024 | 11 | 0 | 0 |
| 2025 | 13 | — | — |
“—” means the source for that year does not report ADU type.
Read more: ADU types explained
ADU rules in San Juan Capistrano
State law check: HCD found the 2024 ordinance noncompliant (December 6, 2024) over its junior-ADU rental rule and a deed restriction on every ADU; the city has amended it since (latest May 2026), and the deed restriction now covers junior ADUs only. We haven't seen HCD's review.
| Rule | San Juan Capistrano's code | State law guarantees |
|---|---|---|
| Maximum size | Locally regulated ADU: 850 sq ft (studio or 1 bedroom) or 1,000 sq ft (2+ bedrooms); attached ADUs 50% of the house, but at least 800 sq ft. State-law detached ADU: 800 sq ft. Junior ADU 500 sq ft. | At least 850 sq ft (1,000 sq ft with 2+ bedrooms) must be allowed; an 800 sq ft detached ADU always is. Conversions of existing space have no size cap. Junior ADU: up to 500 sq ft. |
| Height | Detached: 16 ft (18 ft near transit, plus 2 ft for roof pitch; 18 ft with a multistory apartment building). Attached: 25 ft or the zone limit, 2 stories. | Detached: at least 16 ft (18 ft within ½ mile of transit, plus 2 ft for a matching roof). Attached: 25 ft or the zone's limit, whichever is lower. |
| Setbacks | 4 ft side and rear; 30 ft front for locally regulated ADUs (less if that's the only spot for an 800 sq ft ADU). None for rebuilds in the same footprint. | No more than 4 ft side and rear; none for conversions of existing space. |
| Parking | 1 space per locally regulated ADU, unless exempt (transit, Los Rios or Mission districts, inside existing space, car share, built with a new home); none for state-law ADUs; no replacement parking. | At most 1 space; none within ½ mile of transit and in several other cases. No replacement parking when a garage is converted. |
| Owner living on site | None for ADUs. Junior ADU: the owner lives on site unless it has its own bathroom; deed restriction. | None for ADUs. A junior ADU that shares a bathroom with the house requires the owner to live in one of them. |
| How many on a single-family lot | A converted ADU and a junior ADU, plus one new detached ADU up to 800 sq ft. | One ADU converted from existing space, one junior ADU and one new detached ADU (up to 800 sq ft). From January 1, 2027: two new detached ADUs (a city then needn't allow a junior ADU on that lot). |
| Short-term rentals | 30 days or more, for ADUs and junior ADUs. | No guarantee: cities may require rentals of more than 30 days, and junior ADUs can't be short-term rentals. |
- No ADU or related grading within 200 ft of a ridgeline designated in the General Plan.
- Locally regulated ADUs must match the house's materials and colors, with privacy screening and a 0.35 lot-coverage limit.
- The city offers pre-approved plans for a BOXABL prefabricated studio.
Where local rules conflict with state law, state law controls. Sources: San Juan Capistrano Municipal Code 9-3.501.1 · City ADU page (2026) · HCD findings (December 6, 2024); HCD's list of review letters; California ADU rules. Verified Oct 5, 2026. Rules change and every lot is different: confirm with the city before you design.
How long permits take
Application and issue dates are not published for this area in these sources.
Read more: How long ADUs take to build
From permit to completion
Of the 37 ADU permits San Juan Capistrano reported issuing from 2020 through 2023, 24 (65%) have a completion reported to the state. For those, the median time from permit to completion was 10 months.
The state reports don't record expired or cancelled permits, and a completion the city hasn't reported looks the same as an unfinished project, so the share is a floor. Years with incomplete reports are left out.
What neighbors declared as cost
Cost data (declared permit valuations) is not published for this area in these sources.
Read more: How to choose an ADU builder
An ADU builder serving San Juan Capistrano? Feature your business on this page.
Questions about ADUs in San Juan Capistrano
How many ADUs have been permitted in San Juan Capistrano?
Public records show 65 ADU permits in San Juan Capistrano from 2018 through 2025. 13 in 2025. These counts come from the city's reports to the state, which place a project in its completion year when no permit date was reported.
Can I build an ADU on my property in San Juan Capistrano?
California law allows ADUs on most lots with a house, including in San Juan Capistrano, but what you can build depends on your lot, local rules and utilities. This site shows permits, not eligibility. See California ADU rules.
Where do I apply for an ADU permit in San Juan Capistrano?
Apply with the City of San Juan Capistrano's Development Services Department: a Planning preliminary review by email, then a building permit submitted by appointment. Official ADU page.
How current is this?
- State annual progress reports: through 2025 (published once a year)
How our data works · Download the data · Free to reuse with credit to SoCal ADU Tracker (socaladutracker.com), under CC BY 4.0.