In short
- 122 ADU permits on record, nearly all since 2020.
- 34 in 2025, up 10% from 2024.
- Typical permit time: 167 days from application to permit (median of 50 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 | 1 | — | — |
| 2019 | 1 | — | — |
| 2020 | 4 | — | — |
| 2021 | 13 | — | — |
| 2022 | 19 | — | — |
| 2023 | 19 | — | — |
| 2024 | 31 | — | — |
| 2025 | 34 | — | — |
“—” means the source for that year does not report ADU type.
Read more: ADU types explained
Not counted above: 8 approved projects with no building permit reported yet.
ADU rules in Santee
State law check: HCD sent a technical-assistance letter (May 11, 2026) noting the ordinance on file is from 2023; the city amended its ADU rules in December 2025 and January 2026.
| Rule | Santee's code | State law guarantees |
|---|---|---|
| Maximum size | 800 sq ft for the simplest path. Larger ADUs: 850 sq ft (studio or 1 bedroom) or 1,000 sq ft (2+ bedrooms); attached ones also 50% of the house. 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). Attached: the zone's limit, 35 ft in single-family zones. | 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. Larger ADUs follow the zone's front setback (20 ft in R-1) unless that blocks an 800 sq ft ADU. Conversions: enough for fire safety. | No more than 4 ft side and rear; none for conversions of existing space. |
| Parking | None for ADUs up to 800 sq ft or conversions. Larger ADUs: 1 space unless within ½ mile of transit or another exemption. 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 in the house or the junior ADU when they share sanitation, with a 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 | One converted ADU plus one junior ADU, and one new detached or attached 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 short-term rentals. | No guarantee: cities may require rentals of more than 30 days, and junior ADUs can't be short-term rentals. |
- The ADU fee waiver ended September 27, 2024. ADUs under 750 sq ft pay no impact fees; the city's example puts a 751 sq ft ADU at about $13,700 in impact fees (rates from July 1, 2026).
- Santee accepts the County of San Diego, Chula Vista and Encinitas pre-approved ADU plans, without changes.
- Lots in an Airport Influence Area may need aviation review; ADUs must meet CALGreen Tier II energy measures.
Where local rules conflict with state law, state law controls. Sources: Santee Municipal Code 13.10.045 (amended January 14, 2026) · City of Santee ADU Guide (July 2026) · HCD letter (May 11, 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 | 167 | 104 – 258 | 50 |
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 51 ADU permits Santee reported issuing from 2020 through 2023, 27 (53%) 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 Santee? Feature your business on this page.
Questions about ADUs in Santee
How many ADUs have been permitted in Santee?
Public records show 122 ADU permits in Santee through 2025, nearly all since 2020. 34 in 2025, up 10% 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 Santee?
Among the 50 ADU permits in Santee with both dates recorded, half were issued within 167 days of the application; the middle half took 104 to 258 days. That includes plan-check corrections and resubmittals, not just the review itself.
Can I build an ADU on my property in Santee?
California law allows ADUs on most lots with a house, including in Santee, 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 Santee?
Apply with the City of Santee's Planning & Building Department for a building permit; the city accepts County of San Diego, Chula Vista and Encinitas pre-approved ADU plans. 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.