Commercial Real Estate in Greenbrae: County and Larkspur Jurisdiction, Medical Offices and Zoning

By Matthew Martinez, Founder, CEO & Managing Broker, Diamond Real Estate Group. California DRE #01869679.

Greenbrae is a small, mostly residential community on the hills above Corte Madera Creek and Highway 101, between Kentfield and Larkspur. Its commercial property is concentrated near Sir Francis Drake Boulevard and Bon Air Road: medical offices tied to the hospital campus, the offices at Drakes Landing, and retail near the Bon Air bridge. The first job on any Greenbrae deal is to find out who governs the parcel, because a Greenbrae mailing address does not tell you. Confirm jurisdiction and zoning with Marin County or the City of Larkspur before relying on this page.

Who controls the parcel

Greenbrae is not a city. Much of it is unincorporated and governed by Marin County under the Title 22 Development Code. For example, a 2025 county variance decision for 15 Tamal Vista Lane applied R1-B2 zoning, the SF5 Countywide Plan designation and the Kentfield/Greenbrae Community Plan of 1987.

Other property with a Greenbrae address lies inside the City of Larkspur. The Marin Healthcare District lists its office at 100B Drakes Landing Road, Greenbrae. Yet Larkspur’s own Housing Priority Overlay chapter treats 100 Drakes Landing Road as a city housing site in a PD district. So the same street can be "Greenbrae" for mail and Larkspur for zoning. Check the assessor’s tax rate area or call both planning counters. City parcels follow our Larkspur commercial guide.

Special districts cut across both. The Kentfield Fire Protection District serves Greenbrae along with Kentfield, Kent Woodlands and Del Mesa, covering 3.8 square miles from its station at 1004 Sir Francis Drake Boulevard. For sewer, Sanitary District No. 2 serves portions of the Greenbrae Boardwalk, while other Greenbrae parcels are in the Ross Valley Sanitary District. Confirm the sewer agency for your parcel, since lateral and connection rules differ.

Greenbrae zoning for commercial, industrial and mixed use

For unincorporated parcels, the commercial districts come from county Chapter 22.12. We did not confirm which of these are mapped in Greenbrae, so treat the table as the menu to check against the county zoning map.

District	Intended uses	Notes from the county use table
C1 Retail Business	Community shopping with retail as the main use	Restaurants of 40 patrons or fewer, offices, medical clinics and retail permitted. Hotels permitted. Housing above the first floor only
CP Planned Commercial	Lower-intensity retail, office and housing with design controls	Restaurants of any size, bars, hotels, auto repair and gas stations permitted
AP Administrative and Professional	Offices with compatible housing	Offices and medical clinics permitted. No restaurants or retail
OP Planned Office	Offices and housing	Offices, clinics and extended care permitted
RMPC Residential/Commercial Multiple Planned	Mainly residential with some commercial	Most commercial uses need a use permit. Multifamily permitted
IP Industrial, Planned	Business park and light industry	Vehicle repair and food production by use permit. No housing
Larkspur C-2 and PD (city parcels)	Commercial and planned sites inside Larkspur	Governed by Larkspur Title 18

In C1, CP, AP and some other districts, dwellings other than affordable housing must be accessory to the primary commercial use.

Medical offices and the hospital cluster

Greenbrae’s best-known commercial driver is health care. The Marin Healthcare District holds its board meetings at the MarinHealth Medical Center conference center, 250 Bon Air Road, Greenbrae, and its role includes monitoring the hospital lease. Demand for clinic, lab and medical office space nearby follows the campus.

Under the county table, medical clinics and labs are permitted in C1, CP, AP and OP, but need a use permit in RMPC. Medical hospitals and extended care are permitted in CP and OP and conditional elsewhere. A buyer converting general office to medical use should confirm the district, the parking standard for medical use, and whether the change triggers a use permit. If the parcel is in Larkspur, use the city’s rules instead.

Housing overlays, short-term rentals and permits

Housing overlay. The county’s Housing Overlay Designation (HOD), in Section 22.14.090, allows ministerial approval of housing on listed sites under the county’s form-based code. The county’s central Marin housing sites list shows 23 parcels in neighboring Kentfield but none under Greenbrae. Greenbrae commercial owners in the county should not expect an HOD rezoning to raise land value.

Short-term rentals. Unincorporated Marin requires a county STR license for stays under 30 days. Greenbrae is not one of the townships with its own cap, so it draws from the countywide pool of 1,200 licenses. Hotels, motels and B&Bs are exempt from the STR license.

Planning review. County projects in Greenbrae currently under review are mostly residential design review, variance and ADU permits. Commercial projects follow the same Community Development Agency process, with design review and use permits heard by staff, the Zoning Administrator or the Planning Commission.

Transfer tax, business tax and property tax

For unincorporated Greenbrae, the Marin County Recorder’s transfer tax sheet applies the county rate of $0.55 per $500, net of assumed liens, with no city tax. For Larkspur parcels, the city’s code also contains a documentary stamp tax set by resolution; confirm with escrow. Unincorporated businesses need a county business license under County Code Chapter 5.54, renewed by July 31 and taxed by gross receipts class. A sale generally triggers Proposition 13 reassessment.

Due diligence that matters in Greenbrae

Start with our commercial due diligence checklist, then add:

Confirm county or Larkspur jurisdiction from the tax rate area, not the mailing address.
Pull the zoning and Countywide Plan designation, and read the Kentfield/Greenbrae Community Plan for the area.
For medical tenants, check the district’s use table and medical parking needs.
Identify the sewer agency (Sanitary District No. 2 or Ross Valley Sanitary District) and its lateral rules.
Ask Kentfield Fire about inspection and access requirements for the building.
For county parcels, confirm the business license class and any STR status.

Questions people ask

Is Greenbrae part of Larkspur?

Partly. Much of Greenbrae is unincorporated Marin County, but some Greenbrae-addressed sites, such as Drakes Landing Road, are inside the City of Larkspur.

Who provides fire service in Greenbrae?

The Kentfield Fire Protection District, from its station at 1004 Sir Francis Drake Boulevard.

Can I open a medical office in Greenbrae?

In county C1, CP, AP and OP districts, medical clinics are permitted. In RMPC they need a use permit. In Larkspur, use the city code.

Are there housing overlay sites in Greenbrae?

The county’s central Marin list shows none under Greenbrae. Larkspur’s overlay does include sites with Greenbrae-area addresses inside the city.

Which sewer district serves Greenbrae?

It depends on the parcel. Sanitary District No. 2 serves parts of the Greenbrae Boardwalk, and other parcels are in the Ross Valley Sanitary District.

Is there a city transfer tax?

Not on unincorporated parcels, which pay the county rate. Larkspur parcels should be checked with escrow.

Does Diamond handle commercial property in Greenbrae?

Contact Matthew Martinez to discuss buying, selling or leasing commercial property in Greenbrae.

Sources & notes

Marin County Title 22 Development Code
Marin County Code (GoCodebook): Ch. 22.12, Ch. 22.14
Marin County, Blaufarb variance P5199 (15 Tamal Vista Lane)
Larkspur Ch. 18.101 Housing Priority Overlay
Marin LAFCo: Kentfield Fire Protection District, Sanitary District No. 2, Marin Healthcare District
Marin County, Central Marin housing element sites
Marin County, Short Term Rental License
Marin County Recorder, transfer tax and Marin County business license

Note: We did not open the Kentfield/Greenbrae Community Plan text or the county zoning map, so the districts actually mapped in Greenbrae, and whether the hospital campus and Bon Air Center are inside Larkspur, were not confirmed.

This page is general information, not legal or tax advice. Last reviewed October 2026 by Matthew Martinez.

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