In short
- 44 ADU permits since 2020.
- 7 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).
- Fillmore's state reports include no ADUs before 2020.
Permits by year
Permits by year and type (table)
| Year | All ADU permits | Garage conversions | Detached |
|---|---|---|---|
| 2020 | 3 | — | — |
| 2021 | 4 | — | — |
| 2022 | 12 | — | — |
| 2023 | 12 | — | — |
| 2024 | 6 | — | — |
| 2025 | 7 | — | — |
“—” means the source for that year does not report ADU type.
Read more: ADU types explained
ADU rules in Fillmore
State law check: No HCD review letter on file. The code's recorded deed restriction, and its fire-zone ban that also covers junior ADUs, are the kinds of rules HCD has objected to elsewhere.
| Rule | Fillmore's code | State law guarantees |
|---|---|---|
| Maximum size | Attached: 50% of the house or 850 sq ft (1,000 sq ft with more than 1 bedroom). Detached: 850 or 1,000 sq ft; 800 sq ft with a junior ADU. 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). 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 for new construction. | No more than 4 ft side and rear; none for conversions of existing space. |
| Parking | 1 space per ADU unless exempt; none for junior ADUs. | 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 stated for ADUs. Junior ADU: required. | 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 on a single-family lot, plus the state-law combinations. | 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 | Not for less than 30 days (deed restriction). | No guarantee: cities may require rentals of more than 30 days, and junior ADUs can't be short-term rentals. |
- No ADUs or junior ADUs in Very High Fire Hazard Severity Zones.
- No new ADUs north of Old Telegraph Road and west of A Street, where water and sewer are at capacity.
- The city's web page lists a 1,200 sq ft, 16 ft limit for every ADU, which differs from the code.
Where local rules conflict with state law, state law controls. Sources: Fillmore Municipal Code § 6.04.0415(R) (Ord. 25-984, Oct 26, 2025); HCD's list of review letters; California ADU rules. Verified Sep 29, 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
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 Fillmore? Feature your business on this page.
Questions about ADUs in Fillmore
How many ADUs have been permitted in Fillmore?
Public records show 44 ADU permits in Fillmore from 2020 through 2025. 7 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 Fillmore?
California law allows ADUs on most lots with a house, including in Fillmore, 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 Fillmore?
Apply with the City of Fillmore: an ADU administrative clearance from Community Development, then a building 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.