County directory

Marin 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 Marin County

Belvedere (planning page) (opens the government site in a new tab)
Showing California state rules because Belvedere's local rules may conflict with state law or are being challenged
We show the state rules for a front setback for new ADUs. Check with Belvedere about how it handles this today.
Corte Madera (opens the government site in a new tab)
Showing California state rules because Corte Madera's local rules may conflict with state law or are being challenged
We show the state rules for a one ADU-or-JADU limit, owner-occupancy rules for junior ADUs, and an ADU page the Town says does not yet reflect its January 2025 ordinance changes. Check with Corte Madera about how it handles this today.
Fairfax (opens the government site in a new tab)See our rules summary
Showing Fairfax city rules
These are Fairfax's own ADU rules on file, shown with the California state rules they build on. Each item says which is which.
Where a Fairfax rule may conflict with state law or is being challenged, we show the California state rule instead. This covers a separate Town ADU permit for units state law treats as building-permit-only, a yearly rent-reporting requirement, and extra terms in the junior ADU deed restriction.
Larkspur (opens the government site in a new tab)See our rules summary
Showing California state rules because Larkspur's local rules may conflict with state law or are being challenged
The size, setback, height, and parking figures are California state rules. The Larkspur section lists the local details we have on file, like plans, forms, and contacts.
Where a Larkspur 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.
Mill Valley (opens the government site in a new tab)See our rules summary
Showing California state rules because Mill Valley's local rules may conflict with state law or are being challenged
The size, setback, height, and parking figures are California state rules. The Mill Valley section lists the local details we have on file, like plans, forms, and contacts.
Where a Mill Valley rule may conflict with state law or is being challenged, we show the California state rule instead. This covers a one ADU-or-JADU limit on single-family lots and a Planning step before the building permit for ADUs over 800 sq ft.
Novato (opens the government site in a new tab)See our rules summary
Showing Novato city rules
These are Novato's own ADU rules on file, shown with the California state rules they build on. Each item says which is which.
Where a Novato rule may conflict with state law or is being challenged, we show the California state rule instead. This covers a 50%-of-home size cap on detached ADUs that could block an 800 sq ft unit, front setbacks by zoning district, and limits on combining attached and detached ADUs.
Ross (planning page) (opens the government site in a new tab)
Showing California state rules because Ross's local rules may conflict with state law or are being challenged
We show the state rules for an 800 sq ft cap on detached studio and one-bedroom ADUs (state law allows 850) and owner-occupancy rules for junior ADUs. Check with Ross about how it handles this today.
San Anselmo (opens the government site in a new tab)See our rules summary
Showing California state rules, plus San Anselmo details
The size, setback, height, and parking figures are California state rules. The San Anselmo section lists the local details we have on file, like plans, forms, and contacts.
San Rafael (planning page) (opens the government site in a new tab)
Showing California state rules because San Rafael's local rules may conflict with state law or are being challenged
We show the state rules for an ADU ordinance that a February 2026 state housing department letter says may be outdated. Check with San Rafael about how it handles this today.
Sausalito (opens the government site in a new tab)See our rules summary
Showing Sausalito city rules
These are Sausalito's own ADU rules on file, shown with the California state rules they build on. Each item says which is which.
Where a Sausalito rule may conflict with state law or is being challenged, we show the California state rule instead. This covers a one-story limit for some ADUs and a rule that ADUs in the historic district sit behind the main home.
Tiburon (opens the government site in a new tab)
Showing California state rules
We don't have Tiburon's own ADU rules on file, so this shows the California state rules that apply across the state. Check with Tiburon for local details.
Unincorporated Marin County (opens the government site in a new tab)See our rules summary
Showing California state rules because Marin County's local rules may conflict with state law or are being challenged
The size, setback, height, and parking figures are California state rules. The Marin County section lists the local details we have on file, like plans, forms, and contacts.
Where a Marin County rule may conflict with state law or is being challenged, we show the California state rule instead. This covers County ADU code last amended in 2023, before the 2024 and 2025 state law changes, including owner-occupancy rules for junior ADUs.

All counties in the ADU directory