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

What multifamily in Bolinas looks like

In Bolinas, "multifamily" usually means a house with a legal second unit, a duplex, apartments over a downtown storefront, or a small cluster of older cottages on one parcel. Larger apartment buildings are almost nonexistent. Community land trust housing makes up a meaningful share of the affordable rental stock. The binding limit is water: no new connections have been issued since 1971, so the number of legal units a property can support usually equals what its existing water connection and septic or sewer rights allow. For financing, see financing 2-4 unit properties and apartment building loans.

Where the zoning allows it

Bolinas is unincorporated and entirely in the Coastal Zone. The county’s coastal districts (Chapter 20.62) govern housing types, and most projects also need a Coastal Development Permit.

ADUs and SB 9. ADUs are principally permitted in the coastal residential districts, but a new ADU still needs water. Without a new BCPUD connection, it generally must share an existing one, and on septic it needs county Environmental Health approval. See our ADU investment guide. SB 9 splits are generally unavailable where a parcel is in a hazard area, a historic district or lacks services. The coastal permit process also applies, so most Bolinas parcels are poor SB 9 candidates. 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 puts Marin County in the San Francisco Area region. The maximum increase for covered units is 6.3% from August 1, 2025, and 8.8% from August 1, 2026 through July 31, 2027. There is no local rent cap. See our AB 1482 guide.

County just cause. Bolinas is in unincorporated Marin, so the county’s just cause eviction ordinance applies. Ordinance 3705, now Chapter 5.100, was adopted December 18, 2018. It covers properties with at least three dwelling units on one lot, counting vacant, owner-occupied and short-term rental units. Permitted ADUs and JADUs, subsidized units and on-site manager units are exempt, but unpermitted units are not. It lists for-cause grounds on a three-day notice and no-fault grounds such as owner move-in, substantial remodel and withdrawal from the market. See our just cause eviction guide.

Mandatory mediation. Under the county’s mandatory mediation program, a tenant facing an increase above 5% in 12 months can require free mediation. A landlord who does not take part in good faith risks having the increase deemed invalid.

Bolinas rental property rules

• Short-term rentals. The county’s Chapter 5.41, adopted May 7, 2024, caps Bolinas at 63 licenses initially and 54 over time, with one license per owner. ADUs created after 2020 or 2021, deed-restricted units and multifamily units not legally operating as of January 1, 2024 are ineligible. A Bolinas duplex or ADU should be underwritten as a long-term rental.
• Business license. Rental units in unincorporated Marin need a county business license, billed per unit for rentals and renewed by July 31.
• Transfer tax. Only the county’s $0.55 per $500 applies, per the Recorder’s sheet. There is no city tax.

Water, sewer, septic and the shoreline

The BCPUD’s water moratorium began in November 1971 and is governed by Resolution 173 of 1977. The district’s hazard profile reports 587 water connections fed from Arroyo Hondo Creek, with emergency wells approved in 2021. It also lists only 162 sewer connections downtown and one on the Mesa, a sewer connection moratorium dating to 1985, and capacity problems in very wet years. Elsewhere, septic systems are the rule, and the Gridded Mesa has a county well-drilling policy. On a multi-unit Bolinas property, budget for septic inspection and possible replacement, a water-use review, and bluff or lagoon flood exposure. Older wood-frame cottages may need a seismic retrofit review. Buildings of three or more units with elevated decks need SB 721 inspections.

Underwriting a Bolinas multifamily purchase

1. Get written BCPUD confirmation of each water and sewer connection and the units each one legally serves.
2. Confirm the coastal district, permit history and legal status of every unit, since unpermitted units still count for the county’s just cause rule.
3. Decide whether the county’s just cause ordinance applies (three or more units on the lot) and classify units under AB 1482.
4. Model increases at or below 8.8%, and plan for mediation on anything over 5%.
5. Collect leases, the rent roll and estoppel certificates, plus septic and Environmental Health records.
6. Rebuild expenses with reassessed taxes, septic upkeep 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 (GoCodebook)
3. Marin County, Just Cause Eviction and Mandatory Mediation Program
4. California Attorney General, Rent Caps
5. BCPUD, Water Moratorium
6. BCPUD Jurisdictional Profile, Marin Local Hazard Mitigation Plan
7. Marin County Business License and Recorder transfer tax

Note: We did not read Resolution 173 or the county’s SB 9 implementing rules for the Coastal Zone. Ask the BCPUD how connections can be shared or transferred.

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

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