Marin County, CA Ordinances (2026)

Marin County Code §22.32.120 regulates ADUs in unincorporated areas. Detached and conversion ADUs under 800 square feet receive ministerial by-right approval. ADUs are allowed in single-family, multifamily, and mixed-use zones. The county currently extends its ADU permit fee waiver through December 31, 2026.

Converting a garage to living space in unincorporated Marin County requires a county building permit and zoning review for egress, light/ventilation and parking; creating a separate unit is processed as an ADU under state law.

Sheds in unincorporated Marin County must meet county zoning setbacks. Under the California Building Code, a permit is generally required for accessory structures over 120 square feet; agricultural buildings on ag-zoned land have broader allowances.

Private swimming pools in unincorporated Marin County must comply with the California Building Code pool barrier requirements; Marin's Chapter 19.12 governs decorative pools, ponds, and other artificially created bodies of water that are not intended for swimming.

Construction of a swimming pool in unincorporated Marin County requires a building permit issued by the Community Development Agency Building and Safety Division, which enforces the adopted California Building, Plumbing, Electrical, and Energy Codes.

Marin County does not have a swimming-pool-specific maintenance code for private residential pools; deteriorated, unsanitary, or abandoned pools may be abated under MCC § 19.04.027 (substandard buildings) and California Health & Safety Code § 17920.3, which classifies inadequately maintained structures as public nuisances.

Decorative ponds, fish ponds, and artificial water bodies 18 inches deep or more in unincorporated Marin County must be enclosed by a 5-foot fence with self-closing, self-latching gates, unless they qualify for one of five exemptions under MCC § 19.12.050.

Above-ground pools holding more than 18 inches of water in unincorporated Marin County require a county building permit and the same barrier protection as in-ground pools; ladders must be removable or secured when unattended.

Pool construction in unincorporated Marin County must meet the California Building Code and Swimming Pool Safety Act — a 60-inch barrier, anti-entrapment drain covers, and electrical bonding. A county building permit and inspections are required.

All fireworks — including those marketed as 'safe and sane' — are illegal year-round in Marin County. Possession or use is a misdemeanor with fines of roughly $410 locally, and state law adds $500–$1,000 fines plus possible jail.

Marin County requires 100 feet of defensible space around all structures in Wildland-Urban Interface (WUI) areas. State law (PRC §4291) and the Marin County Fire Code mandate two zones: Zone 1 (0–30 ft, lean and green) and Zone 2 (30–100 ft, reduced fuel).

Most of unincorporated Marin County is designated Wildland-Urban Interface under the Marin County Fire Code (Title 16). WUI properties must meet Chapter 7A construction standards for ignition-resistant materials and maintain 100 feet of defensible space year-round.

Open burning (debris piles, vegetation) is prohibited in unincorporated Marin County from May 1 to October 31. Outside that window, residents need a LE5 California Inter-Agency Burn Permit signed by Marin County Fire and may only burn on declared 'permissive burn days.'

Residents cannot burn debris, vegetation, or open piles in their backyard in unincorporated Marin from May 1 through October 31. Outside that window, a Marin County Fire–signed LE5 burn permit is required and only dry natural vegetation may be burned, with an adult tending at all times.

Residential fire pits and chimineas are generally allowed in unincorporated Marin under the California Fire Code as adopted in Chapter 16.16 MCC, but spark arrestors are required, recreational fires must follow CFC § 307 size and clearance rules, and all outdoor open flames are banned countywide during Red Flag Warnings.

Marin County participates in the FEMA National Flood Insurance Program. Development in mapped Special Flood Hazard Areas (Zones A and AE) must comply with the Floodplain Management Ordinance in Title 23 of the Marin County Code, requiring elevation certificates and finished-floor elevations above the Base Flood Elevation.

Marin County's coastal areas are regulated by the Local Coastal Program (LCP) Implementation Plan, codified in Title 20 of the Marin County Code. Development within the Coastal Zone — including West Marin and Bay shoreline — requires a Coastal Permit. BCDC also regulates within 100 feet of the Bay shoreline.

Marin County Code §6.70.030(5) limits loud noise-generating construction equipment to 8 AM to 5 PM Monday through Friday only. General construction is permitted 7 AM to 6 PM weekdays and 9 AM to 5 PM Saturdays. Construction is prohibited Sundays and listed holidays.

Marin County Code Chapter 6.70 (Loud and Unnecessary Noises) prohibits any loud, raucous, or unnecessary noise that disturbs the peace, comfort, repose, or quiet of any neighborhood or person of normal sensitivity in unincorporated Marin County.

Marin County Code Chapter 6.70 prohibits loud or persistent animal noise that disturbs the peace of neighbors, and Title 8 (Animals) allows Marin Humane to enforce nuisance barking complaints in unincorporated areas through warnings, citations, and impound for repeat offenders.

Marin County Code Title 8 (Animals), Chapter 8.04 requires dogs in public places to be restrained by a leash of sufficient length to allow constant control. Marin Humane enforces leash laws in unincorporated areas and most contracted cities, with fines for off-leash violations.

Marin County has no breed-specific ban. California Food and Agricultural Code § 31683 preempts local breed-based bans, although mandatory spay/neuter ordinances by breed are permitted. The County instead regulates individual dogs through its Potentially Dangerous and Vicious Dog ordinance, § 8.04.181.

In unincorporated Marin County, the Development Code (Title 22, Chapter 22.32) permits the keeping of up to 12 fowl and/or 12 rabbits or similar small animals as 'Livestock Operations, Small Animals.' Large livestock (cattle, goats, sheep, hogs) and equestrian uses are separately defined and zone-restricted.

Marin County Code § 8.04.185 establishes a limitation on the number of dogs per household. Under the Title 22 Development Code, keeping six or more household pets four months or older constitutes a 'kennel' subject to discretionary permitting.

Marin County does not mandate a physical leash in all unincorporated areas, but dogs must at all times be under the immediate control of a competent, responsible person; dogs not under such control may be seized and impounded.

Marin County Code § 8.04.030 requires every dog four months of age or older to be licensed; a current rabies vaccination certificate is a prerequisite. Marin Humane administers licensing under contract with the County.

California restricts exotic pets through the Fish & Game Code and CDFW regulations — ferrets and hedgehogs are illegal statewide, and many wild/exotic species are prohibited. These restrictions apply in unincorporated Marin County.

Beekeeping is broadly allowed in unincorporated Marin County given its agricultural character, subject to county zoning setbacks. Hives must be registered with the county agricultural commissioner.

Marin County requires short-term rental owners to notify occupants of neighboring properties before obtaining or renewing a business license. The 2024 ordinance also limits new non-primary STRs through waitlists when townships exceed their license cap.

Unincorporated Marin County requires every short-term rental (under 30 days) to obtain a STR License, a Business License, and a Transient Occupancy Tax (TOT) Certificate. The countywide cap is 1,200 licenses, with 192 reserved for Stinson Beach and 204 for Dillon Beach. Application fee is $600.

STR guests in unincorporated Marin County are bound by the county noise ordinance — loud or disturbing noise, especially at night, can be cited. West Marin coastal STR areas have active enforcement.

Short-term rentals in unincorporated Marin County are subject to the county Transient Occupancy Tax plus a registration/licensing requirement; West Marin has additional STR caps and restrictions adopted to protect housing. Operators must register and remit.

STR guest parking in unincorporated Marin County must comply with county zoning off-street parking standards; coastal and rural road parking must not obstruct the roadway.

Marin County Code Chapter 22.62 (Tree Removal Permits) requires a permit to remove protected native trees including Coast live oak, California bay, Douglas fir, and Coast redwood — and stricter rules apply to heritage trees. Removing more than two protected trees on a developed lot in 12 months triggers permitting.

In unincorporated Marin County served by Marin Municipal Water District (Marin Water), Ordinance 459 prohibits using district water to irrigate new ornamental lawn in commercial/municipal landscapes, and Ordinance 466 caps new residential turf at 20% of the newly landscaped area or 1,200 sq ft, whichever is less.

Marin County Development Code Chapters 22.27 (Native Tree Protection and Preservation) and 22.62 (Tree Removal Permits) require a Tree Removal Permit before removing Protected or Heritage trees in unincorporated Marin. Routine pruning is generally allowed, but heavy trimming or removal of native oaks and willows triggers permit review.

Marin County Fire Code (Ord. 3775) § 325.5 requires every parcel to be kept free of weeds, dead trees, and other hazardous vegetation that constitute a fire hazard. The Fire Marshal can order tall grass and brush mowed, cleared, or removed.

Marin County Code Chapter 6.60 (Noxious Weeds) and Marin County Fire Code § 325.5 together prohibit allowing noxious weeds or hazardous vegetation to grow on a parcel in unincorporated Marin. The Agricultural Commissioner and Fire Marshal share enforcement.

Most of unincorporated Marin County is within a State Responsibility Area or Very High Fire Hazard Severity Zone. California Public Resources Code § 4291 requires 100 ft of defensible space around every structure, including a 0-5 ft ember-resistant zone (Zone 0), 5-30 ft lean-clean-green zone (Zone 1), and 30-100 ft reduced-fuel zone (Zone 2).

Marin County has no general ordinance banning recreational vehicles, trailers, or boats from parking on streets in unincorporated areas; the 72-hour street-parking limit and any signed restrictions are the primary controls.

In unincorporated Marin County, it is unlawful to park a vehicle on any street or highway for more than 72 consecutive hours; signed roads carry additional posted restrictions enforced by the County.

Marin County has no county-wide overnight parking ban; on County roads designated by Board of Supervisors resolution and posted with signs, no vehicle may park between 11:00 p.m. and 5:00 a.m.

On County roads designated by Board of Supervisors resolution and posted with signs, oversized commercial vehicles (commercial-plated vehicles or combinations exceeding 22 feet) cannot be parked between 11:00 p.m. and 5:00 a.m.

All new buildings and intensified uses in unincorporated Marin must provide minimum off-street parking per Marin County Code Chapter 24.04, with ratios ranging from 1.2 spaces per studio unit to 2.5 spaces per three-bedroom unit and use-based standards for nonresidential development.

Driveway approaches onto county roads in unincorporated Marin County require an encroachment permit from County Public Works and must meet sight-distance, drainage and (in fire areas) emergency-access standards.

In unincorporated Marin County, solid fences and screening walls cannot exceed 6 feet above grade. Within front yards or side yards abutting a street, the limit drops to 4 feet (or up to 6 feet if the portion above 4 feet is at least 50% open).

Marin County does not categorically prohibit fence materials, but fences taller than 4 feet in front yards or street-side setbacks must be at least 50% open above the 4-foot mark. State Zone 0 wildfire rules also affect non-combustible material requirements within 5 feet of structures.

Marin County Development Code § 22.20.050 expressly allows fences up to 4 feet (or 6 feet in non-street-facing yards) to be located within required setbacks or directly on property lines, subject to height limits and corner-lot visibility triangle rules.

Fences up to 6 feet tall in unincorporated Marin County generally do not require a building permit if they comply with zoning. Fences exceeding 6 feet, or in coastal/design-review zones, require a Planning Division permit and may require building permits under Title 19.

Retaining walls in unincorporated Marin County may reach 6 feet above grade when the exposed face points inward, or 4 feet when facing outward (8 feet if 25+ feet from all property lines), under Development Code § 22.20.052.

Shared boundary fences in California are governed by the Good Neighbor Fence Act (CA Civil Code §841), presuming adjoining owners share the cost equally after 30 days' notice — particularly relevant for rural and ranching parcels.

County zoning permits standard fence materials and, in the agricultural and ranching areas of West Marin, allows agricultural and livestock fencing (including barbed wire) where land use supports it.

Unincorporated Marin County does not require a discretionary home-occupation permit. A residential home occupation is an allowed accessory use in every residential district provided the operator obtains and posts a County business license under Chapter 5.54 and complies with the operating standards of Development Code Section 22.32.100.

Marin County Development Code § 22.32.100 allows home occupations as an accessory use in every residential zoning district of the unincorporated County, provided the activity is clearly secondary to full-time residential use, is not visible from the street or neighboring property, creates no off-site nuisance, does not impact on-street parking, and is limited to residents plus at most one nonresident employee. Several use types (vehicle repair, welding, mini-storage, adult businesses, dance/night clubs, etc.) are categorically prohibited.

Marin County Development Code § 22.32.100(B)(3) prohibits window displays and advertising signs for any home occupation in unincorporated Marin. The only on-site identification allowed is a single name plate not exceeding one square foot in area, and no display of merchandise or stock in trade is permitted.

Activities such as catering, ceramics, dressmaking, woodworking, jewelry making, painting, photography, sewing, and other handicrafts are regulated separately as 'cottage industries' under Marin County Development Code § 22.32.060. They require a discretionary Use Permit from the Zoning Administrator (Chapter 22.48) rather than the simple home-occupation business license, but they may then employ nonresident employees as authorized by the review authority.

Home occupations in unincorporated Marin County must not generate traffic, parking demand or deliveries beyond what is normal for a residence; significant customer visits can disqualify the use.