Alameda County · ADU permit data · Updated 2026-10-20
4.3months median, application to building permit, 2023–2025
That is 29% shorter than the Bay Area median of 6.0 months. One in four applicants waited more than 5.9 months.
ADUs permitted in 2023–2025, 88 matched on parcel number. Includes time owners spent revising plans.
Source: California HCD Annual Progress Reports, filed by the City of Alameda
Fast quarter, median and slow quarter, in months
Alameda 2.1–5.9 mo
Alameda County
Bay Area 3.8–10.5 mo
Median Fast quarter to slow quarter
Median wait
Where Alameda sits among 52 ranked cities
Alameda Other ranked cities Bay Area 6.0
Alameda
4.3months
median wait, 2023–2025
State law gives the city 60 days to act once an application is complete. Counted from first submission, this share of ADUs took longer. Ask for the completeness letter, which is due within 15 business days, and keep its date.
Source: HCD Annual Progress Reports, 2023–2025; Gov. Code 66317
Alameda
83%
of matched ADUs
One applicant in four took longer than this. Plan on it if the city sends your plans back for another round of corrections.
Source: HCD Annual Progress Reports, 2023–2025, 75th percentile
Alameda
5.9months
One applicant in four had a building permit within this time from first submission.
Source: HCD Annual Progress Reports, 2023–2025, 25th percentile
Alameda
2.1months
Source: units by calendar year, as reported by the City of Alameda to California HCD
Of every home Alameda permitted in 2023–2025, this share was an ADU.
Source: HCD Annual Progress Reports, 2023–2025
Alameda
36%
Permits a year for every 1,000 detached houses, so small and large cities can be compared.
Source: HCD Annual Progress Reports; DOF housing estimates
Alameda
3.7
rank 28 of 92
Yearly ADU permits in 2023–2025, up 12% from 2019–2021.
Source: HCD Annual Progress Reports
Alameda
+12%
Median time from building permit to certificate of occupancy for ADUs finished in 2023–2025. Add it to the permit wait for a full timeline.
Source: HCD Annual Progress Reports, 2023–2025
Alameda
9.4months
median of 82
One ADU in four took longer than this to reach a certificate of occupancy after the permit.
Source: HCD Annual Progress Reports, 2023–2025, 75th percentile
Alameda
17.7months
Median Fast quarter to slow quarter Bay Area median, 6.0 months Number is the rank out of 52 cities
Every page in Alameda County: median wait where we can measure it, otherwise ADU permits a year
Timeline tool
Pick a start date and see the fast, likely and slow dates for Alameda, from the numbers on this page.
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Answer a few questions about your lot and your plans. We point you to the right kind of help for an ADU in Alameda: an architect, a permit-drawing team, or a design-build firm. About two minutes, no call list.
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Source: Bay Area ADU Permit Clock 2026, our analysis of the California HCD Housing Element Annual Progress Reports (data.ca.gov) filed by the City of Alameda, and DOF housing estimates. Wait times are matched on parcel number and include applicant revision time. The 60-day rule is in Government Code section 66317. How we measured it · See all 109 jurisdictions
For ADUs permitted in 2023–2025, the median time from application to building permit in Alameda was 4.3 months (130 days), based on 88 permits we could match. A quarter took longer than 5.9 months.
Alameda issued 159 ADU building permits in 2023–2025, about 53 a year. ADUs were 36% of all new homes permitted there.
The median time from building permit to certificate of occupancy was 9.4 months for ADUs completed in 2023–2025.