Multifamily and Duplex Properties for Sale in Tomales: Zoning and Rent Rules

What multifamily in Tomales looks like

Tomales has no apartment complexes. Income property here means a village house with a legal second unit, an apartment above or behind a historic storefront, a few cottages on one lot, or housing on a ranch. Ranch housing includes agricultural worker units, which come with their own rules. The village’s sewer serves only about 100 homes, per a 2015 Regional Water Board report, so the supply of legal multi-unit property is small and changes slowly. For financing, see financing 2-4 unit properties and apartment building loans.

Where the zoning allows it

Tomales is unincorporated and in the Coastal Zone. The county’s coastal districts (Chapter 20.62) set housing types, and most projects need a Coastal Development Permit. The county lists a 1997 Tomales Community Plan as the local policy guide.

Uses not listed in the tables are not allowed. Check the zoning map for any C-R2 or C-RMP parcels before you count on more than one primary unit.

Ranch housing. A current county file at 28200 State Route 1 (zoned C-APZ-60) proposes a farmhouse plus two agricultural worker housing units. Such units are tied to the farm operation and cannot be marketed as general rentals. Structures under recorded farmworker restrictions are also barred from short-term rental licenses.

ADUs. At 100 John Street (P5888), an owner seeks a coastal permit for an 800 square foot detached ADU on a five-acre lot, a typical Tomales second-unit project. In the village, an ADU needs sewer capacity from the district. Outside it, the unit needs septic approval. See our ADU investment guide.

SB 9. SB 9 applies to qualifying single-family parcels with adequate services. It does not apply to agricultural zones, and coastal review still applies, so few Tomales parcels qualify. Confirm with the county and see our SB 9 lot split guide.

Rent rules: state law plus Marin County’s just cause and mediation

Rent caps. The Attorney General’s rent cap page places Marin in the San Francisco Area region. Covered units can rise at most 6.3% from August 1, 2025, and 8.8% from August 1, 2026 through July 31, 2027. There is no local cap. See our AB 1482 guide.

County just cause. Marin’s just cause ordinance (Ordinance 3705, Chapter 5.100, December 18, 2018) applies in unincorporated areas like Tomales. It covers lots with three or more dwelling units. Vacant, owner-occupied and short-term rental units count. Permitted ADUs and JADUs, subsidized units and on-site manager units do not, and unpermitted units are not exempt. A ranch with a main house and several older cottages can easily cross the threshold. See our just cause eviction guide.

Mediation. Under the county’s mandatory mediation program, tenants can require mediation of any increase over 5% in 12 months. A landlord who does not take part in good faith risks having the increase deemed invalid.

Tomales rental property rules

• Short-term rentals. The county’s Chapter 5.41 caps Tomales at 12 licenses, falling to 11, with one license per owner and one rental per property. Multifamily units qualify only if legally operating on January 1, 2024, and only for two years. Newer ADUs and farmworker units are ineligible.
• Business license. Rental units need a county business license, billed per unit and renewed by July 31.
• Transfer tax. Only the county’s $0.55 per $500 applies, per the Recorder’s sheet.

Sewer, septic and older buildings

The Tomales Village CSD treats village wastewater in three lined ponds, then spray-irrigates the treated water on grazed pasture in summer. The 2015 Water Board report puts dry-weather design capacity at 43,000 gallons per day, with about 2.6 miles of sewer main and one lift station. It also noted wet-weather inflow swings that a local group attributed to rainwater getting into the pipes. A new or added unit needs the district’s sewer service application, posted on its FAQ page. Outside the district, plan for a county septic inspection.

Tomales has many older wood-frame buildings, so a seismic retrofit review of any mixed-use or multi-unit structure is worthwhile. Buildings of three or more units with elevated decks need SB 721 inspections.

Underwriting a Tomales multifamily purchase

1. Confirm the sewer connection and the units it covers with the Tomales Village CSD, or get the septic permit and inspection if outside the district.
2. Confirm the water source and its permits.
3. Verify the coastal district and the permit status of every unit, and flag any farmworker housing restrictions.
4. Apply the county just cause test (three or more units on the lot) and classify each unit under AB 1482, modeling increases at or below 8.8%.
5. Collect leases, the rent roll and estoppel certificates.
6. Rebuild expenses with reassessed taxes, sewer charges and the county license in our rental property analysis.

Questions people ask

Sources & notes

1. Marin County Code Ch. 20.62, Coastal Zoning Districts (GoCodebook)
2. Marin County Code Ch. 5.41, Short Term Rentals
3. Marin County projects P6126 and P5888
4. Tomales Village CSD, wastewater plant and sewer FAQ
5. SF Bay Regional Water Board staff report (2015)
6. Marin County, Just Cause Eviction and Mandatory Mediation
7. California Attorney General, Rent Caps
8. Marin County, Community and Area Plans
9. Marin County Business License and Recorder transfer tax

Note: We did not confirm whether C-R2 or C-RMP districts are mapped in Tomales, read the 1997 plan, or identify the village’s water provider.

General information, not legal or tax advice. Last reviewed October 2026 by Matthew Martinez.

Related: Tomales real estate guide · Commercial real estate in Tomales · Multifamily investing guide · Investor services