County directory

Sonoma County ADU rules

Each place name links to that city or county's own ADU page. Places with a 'See our rules summary' button also have our plain-language summary of the local ADU rules, with sources. Each place below says whether we show local rules or California state rules.

Places in Sonoma County

Cloverdale (planning page) (opens the government site in a new tab)
Showing California state rules because Cloverdale's local rules may conflict with state law or are being challenged
We show the state rules for an ADU ordinance that a December 2025 state housing department letter says may be outdated. Check with Cloverdale about how it handles this today.
Cotati (opens the government site in a new tab)See our rules summary
Showing California state rules, plus Cotati details
The size, setback, height, and parking figures are California state rules. The Cotati section lists the local details we have on file, like plans, forms, and contacts.
Healdsburg (opens the government site in a new tab)See our rules summary
Showing California state rules because Healdsburg's local rules may conflict with state law or are being challenged
The size, setback, height, and parking figures are California state rules. The Healdsburg section lists the local details we have on file, like plans, forms, and contacts.
Where a Healdsburg rule may conflict with state law or is being challenged, we show the California state rule instead. This covers owner-occupancy rules for junior ADUs.
Petaluma (opens the government site in a new tab)See our rules summary
Showing Petaluma city rules
These are Petaluma's own ADU rules on file, shown with the California state rules they build on. Each item says which is which.
Rohnert Park (opens the government site in a new tab)See our rules summary
Showing California state rules, plus Rohnert Park details
The size, setback, height, and parking figures are California state rules. The Rohnert Park section lists the local details we have on file, like plans, forms, and contacts.
Santa Rosa (opens the government site in a new tab)See our rules summary
Showing Santa Rosa city rules
These are Santa Rosa's own ADU rules on file, shown with the California state rules they build on. Each item says which is which.
Where a Santa Rosa rule may conflict with state law or is being challenged, we show the California state rule instead. This covers percentage-of-home size caps for attached ADUs and additions.
Sebastopol (opens the government site in a new tab)See our rules summary
Showing California state rules because Sebastopol's local rules may conflict with state law or are being challenged
The size, setback, height, and parking figures are California state rules. The Sebastopol section lists the local details we have on file, like plans, forms, and contacts.
Where a Sebastopol rule may conflict with state law or is being challenged, we show the California state rule instead. This covers owner-occupancy rules for junior ADUs in the City's 2023 ADU guide.
Sonoma (planning page) (opens the government site in a new tab)
Showing California state rules because Sonoma's local rules may conflict with state law or are being challenged
We show the state rules for a one-ADU limit, an owner-occupancy rule, and size caps (30% of the home for attached ADUs) in rules the City last updated in 2020. Check with Sonoma about how it handles this today.
Windsor (opens the government site in a new tab)See our rules summary
Showing Windsor city rules
These are Windsor's own ADU rules on file, shown with the California state rules they build on. Each item says which is which.
Where a Windsor rule may conflict with state law or is being challenged, we show the California state rule instead. This covers an 800 sq ft cap on studio and one-bedroom ADUs (state law allows at least 850).
Unincorporated Sonoma County (planning page) (opens the government site in a new tab)See our rules summary
Showing Sonoma County rules
These are Sonoma County's own ADU rules on file, shown with the California state rules they build on. Each item says which is which.
Where a Sonoma County rule may conflict with state law or is being challenged, we show the California state rule instead. This covers a ban on ADUs in the Z Combining District and extra terms in the required junior ADU deed restriction.

All counties in the ADU directory