In short
- 140 ADU permits on record, nearly all since 2020.
- 28 in 2025, up 33% from 2024.
- Typical permit time: 276 days from application to permit (median of 88 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 | 2 | — | — |
| 2019 | 2 | — | — |
| 2020 | 13 | — | — |
| 2021 | 23 | — | — |
| 2022 | 24 | — | — |
| 2023 | 27 | — | — |
| 2024 | 21 | — | — |
| 2025 | 28 | — | — |
“—” means the source for that year does not report ADU type.
Read more: ADU types explained
Not counted above: 41 approved projects with no building permit reported yet.
ADU rules in Del Mar
State law check: No HCD review letter on file; that is not a finding of compliance.
| Rule | Del Mar's code | State law guarantees |
|---|---|---|
| Maximum size | 850 sq ft, or 1,000 sq ft with more than one bedroom; attached ADUs 50% of the house (800 sq ft if the house is under 1,600 sq ft). An 800 sq ft ADU is allowed unless it would harm coastal resources. | 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). Attached: 16 ft on the first story; a second story (up to 25 ft) only if there's no room on the ground. 14 ft in the Bluff, Slope and Canyon Overlay. | 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, with no eaves in them; the zone's street setbacks unless needed for an 800 sq ft ADU. Coastal bluff, beach and habitat setbacks still apply. | No more than 4 ft side and rear; none for conversions of existing space. |
| Parking | None near a major transit stop. 1 space in the Coastal Commission appeals area (shoreline and high-fire hillsides) or on streets 20 ft wide or less, unless exempt. Replacement parking only if losing it affects shoreline access. | 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 | The code's plan notes say the owner lives on the property (house, ADU or junior ADU) from January 1, 2025. | 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 ADU plus one junior ADU on a single-unit lot, but only when the ADU is detached; an attached ADU or one inside the house can't be combined with a junior ADU. | 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 | Longer than 30 consecutive days in residential zones. | No guarantee: cities may require rentals of more than 30 days, and junior ADUs can't be short-term rentals. |
- Coastal Zone: most new ADUs need an administrative coastal development permit (no hearing; neighbors are noticed). Conversions inside the house are exempt.
- The chapter (Ordinances 1002 and 1017) was certified by the Coastal Commission on June 12, 2025.
- Objective design rules apply: no roof decks, privacy-minded windows, Dark Sky lighting, and public views protected.
- A deed restriction is recorded before the building permit.
- State law now bars owner-occupancy rules for ADUs; it controls where the code differs.
Where local rules conflict with state law, state law controls. Sources: Del Mar Municipal Code Chapter 30.91 · City of Del Mar ADU plans 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 |
|---|---|---|---|
| Unclassified | 276 | 193 – 404 | 88 |
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 86 ADU permits Del Mar reported issuing from 2020 through 2023, 59 (69%) have a completion reported to the state. For those, the median time from permit to completion was 15 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 Del Mar? Feature your business on this page.
Questions about ADUs in Del Mar
How many ADUs have been permitted in Del Mar?
Public records show 140 ADU permits in Del Mar through 2025, nearly all since 2020. 28 in 2025, up 33% 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 Del Mar?
Among the 88 ADU permits in Del Mar with both dates recorded, half were issued within 276 days of the application; the middle half took 193 to 404 days. That includes plan-check corrections and resubmittals, not just the review itself.
Can I build an ADU on my property in Del Mar?
California law allows ADUs on most lots with a house, including in Del Mar, 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 Del Mar?
Apply with the City of Del Mar's Planning and Community Development Department: a building permit and, for most new ADUs, an administrative coastal development permit. 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.