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Solano County · ADU permit data · Updated 2026-10-20

How long does an ADU permit take in Vacaville?

54permits a year ADU building permits, 2023–2025 average

Bay Area
6.0 mo
Status
Too few
Rank
unranked

We cannot publish a reliable wait time for Vacaville. Fewer than 10 ADUs here could be matched from application to permit in 2023–2025.

State limit
60 days
Bay Area
6.0 mo
months
Months from application to ADU permit, 2023–2025, drawn to one scale. The state's 60-day clock starts once an application is complete.
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Permit wait

All 52 ranked cities

Months from ADU application to building permit

Bay Area figures for reference. Fewer than 10 ADUs here could be matched from application to permit in 2023–2025.

Source: California HCD Annual Progress Reports, filed by the City of Vacaville

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Fast quarter, median and slow quarter, in months

Solano County

Bay Area 3.8–10.5 mo

Median Fast quarter to slow quarter

Median wait

  • Solano County 6.1 mo
  • Bay Area 6.0 mo
  • Benicia fastest nearby 3.3 mo
  • Vallejo slowest nearby 8.3 mo

Median wait in the 52 ranked cities

Other ranked cities Bay Area 6.0

Bay Area

6.0months

median of 5,578 matched Bay Area permits, 2023–2025

Permits issued

163 ADU permits, 2023–2025

ADU building permits issued and ADUs finished, by year

Source: units by calendar year, as reported by the City of Vacaville to California HCD

Vacaville, units per year

0 50 100 2018: 9 Permits issued2019: 3 Permits issued2020: 10 Permits issued2021: 15 Permits issued2022: 27 Permits issued2023: 24 Permits issued2024: 92 Permits issued2025: 47 Permits issued 2018: 0 ADUs completed2019: 1 ADUs completed2020: 3 ADUs completed2021: 6 ADUs completed2022: 5 ADUs completed2023: 4 ADUs completed2024: 2 ADUs completed2025: 98 ADUs completed 47 Permits issued 98 ADUs completed 20182020202220242025

ADU permits a year, 2023–2025 average

  • Vacaville 54
  • Vallejo 31
  • Fairfield 16
  • Unincorporated Solano County 14
  • Solano County, all 137
  • Bay Area, all 4,316

ADU permits a year per 1,000 houses, 109 places

Vacaville 2.0

Vacaville Other Bay Area places

Vacaville

54a year

ADU permits, 2023–2025 average

Share of new homes that are ADUs

Of every home Vacaville permitted in 2023–2025, this share was an ADU.

Source: HCD Annual Progress Reports, 2023–2025

Vacaville

12%

ADU permits per 1,000 houses

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

Vacaville

2.0

rank 68 of 92

Change since 2019–2021

Yearly ADU permits in 2023–2025, up 482% from 2019–2021.

Source: HCD Annual Progress Reports

Vacaville

+482%

Build time

100 finished ADUs

Building permit to finished ADU

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

Vacaville

8.2months

median of 100

Slow quarter of builds took longer than

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

Vacaville

9.1months

Solano County

8 cities and areas · all cities
Months from ADU application to building permit

Median Fast quarter to slow quarter Bay Area median, 6.0 months Number is the rank out of 52 cities

06121824
median
  1. 7Benicia
    3.3
  2. 14Unincorporated Solano County
    4.6
  3. 45Vallejo
    8.3

Every page in Solano County: median wait where we can measure it, otherwise ADU permits a year

Planning an ADU in Vacaville

  1. 1 After the permit, ADUs here took a median of 8.2 months to reach a certificate of occupancy (Bay Area: 13.0).
  2. 2 Vacaville permits about 54 ADUs a year, up 482% from 2019–2021. Local designers and builders have recent examples to show you; ask for permitted ADUs in Vacaville, not elsewhere.
  3. 3 The part of the wait you control is the first submission. Complete drawings, a site plan that matches the survey, and answers to the city's ADU checklist cut down on correction rounds.
  4. Read next: why home plans get sent back · permit drawings vs. full plans · architect fee calculator

Timeline tool

When would your permit come through?

Pick a start date and see the fast, likely and slow dates for Vacaville, from the numbers on this page.

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Next step

Not sure who to call first?

Answer a few questions about your lot and your plans. We point you to the right kind of help for an ADU in Vacaville: an architect, a permit-drawing team, or a design-build firm. About two minutes, no call list.

Find the right first call

Start with the city's own rules: City ADU page.

Sheet
C-204
Drawing
ADU permit record, Vacaville
Source
California HCD Annual Progress Reports, filed by the City of Vacaville
Date
2026-10-20
Scale
Not to scale

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 Vacaville, 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

Common questions

How long does it take to get an ADU permit in Vacaville?

There are not enough comparable records to give a reliable number for Vacaville. Across the Bay Area the median was 6.0 months.

How many ADUs does Vacaville approve?

Vacaville issued 163 ADU building permits in 2023–2025, about 54 a year. ADUs were 12% of all new homes permitted there.

How long does it take to build an ADU in Vacaville?

The median time from building permit to certificate of occupancy was 8.2 months for ADUs completed in 2023–2025.