In short
- 193 ADU permits since 2018.
- 31 in 2025, down 35% from 2024.
- Typical permit time: 232 days from application to permit (median of 123 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 | 12 | — | — |
| 2019 | 9 | — | — |
| 2020 | 12 | — | — |
| 2021 | 25 | — | — |
| 2022 | 31 | — | — |
| 2023 | 25 | 0 | 0 |
| 2024 | 48 | — | — |
| 2025 | 31 | — | — |
“—” means the source for that year does not report ADU type.
Read more: ADU types explained
ADU rules in Lemon Grove
State law check: HCD found the city's ADU rules out of line with state law (December 10, 2025), including its one-ADU limit, 16 ft detached height and front setbacks; the code hasn't changed since 2022, so state law controls.
| Rule | Lemon Grove's code | State law guarantees |
|---|---|---|
| Maximum size | 1,200 sq ft or the size of the house, whichever is less; 800 sq ft is always allowed. Conversions have no cap (plus 150 sq ft for entry). Junior ADU 150 to 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. Attached and internal ADUs: the same limit as the house in that zone. | 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 (less if the zone allows); front setback per the zone. Conversions: none. | No more than 4 ft side and rear; none for conversions of existing space. |
| Parking | 1 space per ADU unless exempt (transit within ½ mile, conversions, car share and more); no replacement for a converted garage. A garage converted to a junior ADU must be replaced. | 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, 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 ADU and one junior ADU on a lot with one house; one ADU on a lot with more than one house. | 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 less needs a home-sharing permit, and the host must live in that unit during the stay. An ADU counts as its own unit. | No guarantee: cities may require rentals of more than 30 days, and junior ADUs can't be short-term rentals. |
- ADUs are allowed in the RL, RLM, RM, RMH, RP and CG zones.
- ADUs must match the house's architectural style, materials and colors.
- The city posts pre-approved ADU plans (2025).
Where local rules conflict with state law, state law controls. Sources: Lemon Grove Municipal Code 17.24.060 D.1 (2022) · Lemon Grove Municipal Code 18.48.020 (home-sharing) · City of Lemon Grove ADU development standards handout · HCD findings (December 10, 2025); 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 |
|---|---|---|---|
| Junior ADU (JADU) | 0 | 0 – 108 | 13 |
| Unclassified | 247 | 161 – 378 | 110 |
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 92 ADU permits Lemon Grove reported issuing from 2020 through 2023, 20 (22%) have a completion reported to the state. For those, the median time from permit to completion was 12 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 Lemon Grove? Feature your business on this page.
Questions about ADUs in Lemon Grove
How many ADUs have been permitted in Lemon Grove?
Public records show 193 ADU permits in Lemon Grove from 2018 through 2025. 31 in 2025, down 35% 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 Lemon Grove?
Among the 123 ADU permits in Lemon Grove with both dates recorded, half were issued within 232 days of the application; the middle half took 140 to 353 days. That includes plan-check corrections and resubmittals, not just the review itself.
Can I build an ADU on my property in Lemon Grove?
California law allows ADUs on most lots with a house, including in Lemon Grove, 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 Lemon Grove?
Apply with the City of Lemon Grove's Community Development Department, which posts its ADU standards and 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.