In short
- 540 ADU permits since 2018.
- 81 in 2025, up 23% from 2024.
- Typical permit time: 132 days from application to permit (median of 214 permits with both dates recorded).
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 | 50 | — | — |
| 2019 | 47 | — | — |
| 2020 | 52 | 0 | 1 |
| 2021 | 71 | 0 | 1 |
| 2022 | 84 | 0 | 1 |
| 2023 | 89 | — | — |
| 2024 | 66 | 0 | 0 |
| 2025 | 81 | — | — |
“—” means the source for that year does not report ADU type.
Read more: ADU types explained
Not counted above: 64 approved projects with no building permit reported yet.
ADU rules in Carlsbad
State law check: No HCD review letter on file; that is not a finding of compliance.
| Rule | Carlsbad's code | State law guarantees |
|---|---|---|
| Maximum size | Detached: 1,200 sq ft. Attached: 50% of the house or 1,200 sq ft, whichever is less, but at least 800 sq ft. Conversions stay within the existing space. 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 a major transit stop, plus 2 ft for a matching roof). Attached: 25 ft or the zone limit, whichever is higher, 2 stories at most. No roof decks. | 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 | The city's ADU section defers to state law. | No more than 4 ft side and rear; none for conversions of existing space. |
| Parking | 1 space (covered or uncovered, tandem allowed) unless exempt under state law. No replacement parking for a converted garage, except west of the rail corridor and in a coastal area between the rail corridor and I-5. | 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 | No owner-occupancy rule in the code. Junior ADU: a recorded deed restriction (no separate sale). | 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 | One junior ADU with a one-family home; the number of ADUs follows state law (Gov. Code 66314 and 66323). | 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 | ADUs and junior ADUs permitted since January 1, 2020 are left out of the city's short-term vacation rental program. | No guarantee: cities may require rentals of more than 30 days, and junior ADUs can't be short-term rentals. |
- Coastal Zone: ADUs and junior ADUs there need a coastal development permit as well as a building permit.
- The latest update (Ordinance CS-506, February 3, 2026) is pending Coastal Commission certification inside the Coastal Zone.
- New ADUs must respect habitat preserve buffers, geologic setbacks and coastal view policies.
- The city offers free pre-approved ADU plans (Permit Ready program).
Where local rules conflict with state law, state law controls. Sources: Carlsbad Municipal Code 21.10.030 · Carlsbad Municipal Code 21.44.020 (parking) · Carlsbad Municipal Code 5.60.020 (short-term rentals) · City of Carlsbad ADU page (checked October 5, 2026); 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
| Type | Median days, application to permit | Middle half | Permits |
|---|---|---|---|
| Detached ADU | too few to say | 1 | |
| Junior ADU (JADU) | too few to say | 1 | |
| Unclassified | 130 | 67 – 247 | 212 |
Middle half: the range covering the middle 50% of permits (a quarter were lower, a quarter higher).
Read more: How long ADUs take to build
From permit to completion
Of the 277 ADU permits Carlsbad reported issuing from 2020 through 2023, 223 (81%) have a completion reported to the state. For those, the median time from permit to completion was 11 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
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Questions about ADUs in Carlsbad
How many ADUs have been permitted in Carlsbad?
Public records show 540 ADU permits in Carlsbad from 2018 through 2025. 81 in 2025, up 23% from 2024. 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.
How long does an ADU permit take in Carlsbad?
Among the 214 ADU permits in Carlsbad with both dates recorded, half were issued within 132 days of the application; the middle half took 68 to 246 days. That includes plan-check corrections and resubmittals, not just the review itself.
Can I build an ADU on my property in Carlsbad?
California law allows ADUs on most lots with a house, including in Carlsbad, 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 Carlsbad?
Apply with the City of Carlsbad's Building Division, which also offers free pre-approved ADU plans through its Permit Ready program. 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.