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

What multifamily in Larkspur looks like

Larkspur’s rental stock is a mix of older duplexes and small apartment buildings on the flatter streets near downtown and Magnolia Avenue, garden-style complexes and condominiums from the 1960s and 1970s, upstairs units over downtown storefronts, and a mobile home park district. New multifamily supply is coming mostly from the Housing Element sites around Larkspur Landing near the ferry terminal. What sets Larkspur apart from most of Marin is that it has its own rent stabilization ordinance, so the rent roll is regulated more tightly than in neighboring towns. For loan options, see financing 2-4 unit properties and apartment building loans.

Where the zoning allows it

Larkspur’s Title 18 has two residential districts that allow more than one primary unit, plus downtown and overlay districts that permit multifamily outright.

Condominium conversions. In the downtown districts, converting existing rental buildings to condominiums or stock cooperatives needs a use permit and must meet Chapter 18.38. Do not price a building on a condo exit without reading it.

ADUs. ADUs and JADUs follow Chapter 18.23. See our ADU investment guide.

SB 9. Larkspur’s Chapter 18.100, last amended by Ordinance 1091 in 2025, applies two-unit projects and urban lot splits only in R-1 and in planned development districts that allow single-family use. Lot splits need an affidavit that the owner will live in one unit for at least three years, new lots must be at least 1,200 square feet, side and rear setbacks are 4 feet, and a deed restriction bars rentals under 30 days. See our SB 9 lot split guide. SB 9 is a path for owner-users, not for investors buying R-2 or R-3 buildings.

Rent rules: local rent stabilization

Larkspur’s cap. Chapter 6.20, adopted by Ordinance 1067 in 2023, is one of the few local rent stabilization laws in Marin. Under Section 6.20.040, rent may not rise by more than 5% plus the change in the San Francisco–Oakland–Hayward CPI, or 7%, whichever is lower. Only one increase is allowed in any 12-month period. An owner who needs more can file a fair return petition, and the city manager’s decision can be appealed.

Who is exempt. Section 6.20.070 exempts units with a certificate of occupancy issued after February 1, 1995, as Costa-Hawkins requires, plus deed-restricted affordable housing, dormitories, and permitted ADUs and JADUs. Separately alienable units such as single-family homes and condos are exempt if the owner is not a REIT, corporation or LLC with a corporate member and the tenant got written notice of the exemption. A duplex where the owner lived in one unit when the tenancy began, and still does, is exempt as long as neither unit is an ADU. So are units the owner or immediate family occupied at the start of the tenancy, transient lodging and institutional housing.

Notices. Section 6.20.090 requires a city-form notice before a covered tenancy begins, and every rent increase notice must describe the chapter and the tenant’s rights in the fair return process. An increase cannot take effect until those notices are given, in the language of the lease or the tenant’s known primary language. A seller who skipped these notices may be passing an unenforceable rent roll to you.

State law on top. The Attorney General’s rent cap page lists the AB 1482 cap for the San Francisco area, which includes Marin, at 8.8% for increases from August 1, 2026 through July 31, 2027. Larkspur’s lower cap controls where it applies, and AB 1482 just cause rules still govern terminations. See our guides to AB 1482 and just cause eviction.

Not in the county mediation program. The county’s mandatory mediation program covers only unincorporated Marin, San Rafael and Fairfax, so Larkspur landlords are not subject to its over-5% mediation rule.

Larkspur rental property rules

• Multi-unit inspections. Marin County Environmental Health runs a multi-unit rental housing inspection program for buildings of three or more units everywhere in the county except San Rafael and Novato. Owners file an operating permit application and pay an annual fee. Ask the seller for the current permit.
• Rent stabilization fees. Chapter 6.20 includes a fees section (6.20.110). Confirm whether the city charges a per-unit fee and whether it can be passed through.
• Short-term rentals. Units created under SB 9 may not be rented for less than 30 days. We did not find a separate citywide STR chapter in Title 18, so confirm current rules with the city.
• Inclusionary and density bonus. New projects follow Chapter 18.25 (inclusionary and in-lieu fees) and Chapter 18.26 (density bonus).

Older buildings, slopes and sewer laterals

Much of Larkspur’s rental housing dates from the 1960s and 1970s, when tuck-under parking and wood-frame construction over open ground floors were common. Ask for any seismic evaluation and see our seismic retrofit guide. Buildings with three or more units and elevated balconies, decks or stairways need SB 721 inspections. Hillside parcels fall under the city’s slope and hillside rules in Chapter 18.34, which can limit additions. The Ross Valley Sanitary District requires a private sewer lateral Certificate of Compliance when a property in its service area is sold. Confirm which agency serves the parcel and order a video inspection early.

Underwriting a Larkspur multifamily purchase

1. Confirm the district and lot area, and test the legal unit count against R-2 or R-3 standards.
2. Pull certificates of occupancy to see whether each unit is covered by Chapter 6.20 or exempt as post-1995 construction.
3. Recompute every rent increase in the last 12 months against the 5% plus CPI or 7% cap, and check that the city-form notices were served.
4. Gather leases, exemption notices and estoppel certificates for every unit.
5. Get the county multi-unit permit, SB 721 report and sewer lateral status.
6. Model capped rent growth, reassessed taxes and actual costs in our rental property analysis.

Questions people ask

Sources & notes

1. Larkspur Municipal Code Title 18 index and chapters 18.100, 18.101 (GoCodebook, Oct. 2026)
2. Larkspur Municipal Code: § 18.28.030, § 18.32.030
3. Larkspur Chapter 6.20: index, § 6.20.040, § 6.20.070, § 6.20.090
4. California Attorney General, Rent Caps
5. Marin County, Mandatory Mediation Program
6. Marin County Environmental Health, Multi-Unit Rental Housing Inspection
7. Ross Valley Sanitary District, compliance

Note: We did not read R-2 and R-3 permitted-use and height sections, Chapter 18.38, the fair return procedure, the fee resolution or the zoning map. The current CPI-based cap figure should be confirmed with the city each year.

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

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