Sonoma State University, CA

Unincorporated Sonoma County allows accessory dwelling units (ADUs) and junior accessory dwelling units (JADUs) ministerially in any zoning district that permits a single-family or multi-family primary dwelling, under Sonoma County Code Section 26-88-060 (ADUs) and Section 26-88-061 (JADUs). The current inland ADU ordinance was adopted by the Board of Supervisors on December 5, 2023 and took effect January 4, 2024, implementing California Government Code Sections 65852.2 and 65852.22 along with the suite of state ADU bills (AB 68, SB 13, AB 881, AB 670, AB 671, SB 897, AB 2221, AB 1033, SB 1211, AB 2533). Detached new-construction ADUs are capped at 1,200 square feet, attached ADUs at 50% of the primary dwelling or 1,200 square feet (whichever is less, but at least 800 sq ft must be allowed), and JADUs at 500 square feet contained within an existing or proposed single-family dwelling. State law guarantees an 18-foot height for detached ADUs (16 feet plus 2 feet for roof pitch) on most lots, 4-foot side and rear setbacks, no minimum lot size, and no owner-occupancy requirement for ADUs permitted between January 1, 2020 and January 1, 2025. JADUs require the owner to live in either the primary dwelling or the JADU and a recorded deed restriction. ADUs and JADUs in unincorporated Sonoma County may not be rented for terms shorter than 30 days, and properties in the State Responsibility Area (SRA), Local Responsibility Area Very High Fire Hazard Severity Zone, or Wildland-Urban Interface (WUI) must meet California Building Code Chapter 7A ignition-resistant construction and PRC 4291 / Sonoma County defensible space requirements - heightened standards adopted in response to the 2017 Tubbs Fire, 2019 Kincade Fire, and 2020 Glass Fire that destroyed thousands of homes countywide. The County has not adopted an AB 1033 condominium-conversion ordinance, so ADUs in unincorporated Sonoma County cannot currently be sold separately from the primary dwelling.

Sonoma County allows one-story detached accessory structures used as tool or storage sheds without a building permit when located on a parcel with an existing single-family dwelling, provided the structure does not exceed 120 square feet of floor area and 12 feet in height above grade, under Sonoma County Permit Sonoma Administrative Manual 1-4-6 and California Building Code Sec. R105.2 as adopted in Chapter 7 of the County Code. No more than one such permit-exempt structure is allowed unless separated from another by more than 50 feet. Sheds and other detached accessory structures exceeding 120 square feet require a building permit, must not exceed 15 feet in height (Sec. 26-88-040 and Permit Sonoma 1-4-6), are prohibited in required front and street-side setbacks and in designated creek setback areas, and may not cover more than 50% of the required rear yard. In CAL FIRE State Responsibility Areas or Very High Fire Hazard Severity Zones, sheds within 30 feet of any structure must meet Public Resources Code Sec. 4291 defensible-space rules, and sheds within 5 feet of a property line may require fire-resistive construction under California Residential Code Sec. R302. Sheds in Scenic Resources (SR), Coastal (CC), and Floodway combining districts have additional siting and material requirements.

Sonoma County permits garage conversions to accessory dwelling units (ADUs) ministerially under Sec. 26-88-060 of the Zoning Code and California Government Code Sec. 65852.2, with no replacement off-street parking required when the converted garage previously satisfied a parking requirement. Conversion ADUs are limited to the existing dimensions of the structure plus an addition of up to 150 square feet for ingress and egress. Side and rear setbacks for converted garages are 0 feet (legal-existing) for the existing footprint and 4 feet for any new construction. Garage conversions to non-ADU living space (a den, family room, or bedroom that's still part of the main dwelling) are a separate building-permit pathway under Chapter 7 of the County Code, do require the original off-street parking to be replaced elsewhere on the parcel under Sec. 26-86-010, and must meet California Residential Code habitability standards (minimum ceiling heights, egress windows, natural light, ventilation, smoke and carbon monoxide alarms). Conversion of a garage to a Junior ADU (JADU) under Sec. 26-88-061 is allowed when the garage is attached to the single-family dwelling and the JADU is capped at 500 square feet. Garage conversions in SRA, Very High Fire Hazard Severity Zones, or WUI must meet California Building Code Chapter 7A ignition-resistant standards if exterior elements are altered, and defensible space under PRC Sec. 4291 must be maintained.

All fireworks - including state-approved 'Safe and Sane' fireworks and sparklers - are illegal everywhere in unincorporated Sonoma County. The ban traces to the catastrophic Tubbs (2017), Kincade (2019), and Glass/Walbridge (2020) fires; the Sheriff's Office and Permit Sonoma enforce it strictly on and around July 4. The only fireworks lawfully discharged in unincorporated areas are licensed public displays operated by a California state-licensed pyrotechnic operator with a permit from the Sonoma County Fire Marshal under California Health & Safety Code Section 12500 et seq.

Sonoma County Code Chapter 13A (the Hazardous Vegetation Abatement Ordinance, Ord. 6148) requires every improved parcel in the unincorporated county - and every unimproved parcel inside a State or Local Responsibility Area - to maintain 100 feet of defensible space around structures, plus 10 feet of clearance along roads and driveways. Annual inspections begin in late spring, with about 4,000 properties checked each year. Failure to comply triggers re-inspection fees, county-contracted abatement billed to the owner, and recordation of a lien against the property.

Outdoor burning of any vegetative waste in unincorporated Sonoma County requires two permits: an air-quality burn permit from the local air-pollution control district (Northern Sonoma County APCD in northern parts of the county; Bay Area AQMD in southern parts), and - if the parcel is in the State Responsibility Area - a free CAL FIRE burn permit during declared fire season. Permits are typically suspended from late spring through the first significant rains and during any Red Flag warning. Only natural dry vegetation grown on the property may be burned; household trash, painted wood, and treated lumber are always prohibited.

Unincorporated Sonoma County operates under the County Fire Safety Ordinance (Chapter 13 of the Sonoma County Code) which adopts the California Fire Code with local amendments. Open-flame recreational fires (including backyard fire pits and chimineas) are tightly controlled because much of the unincorporated county lies in a Very High Fire Hazard Severity Zone. During declared fire season and on any 'Red Flag' or PSPS day, the Fire Marshal routinely suspends recreational burning. Gas- and propane-fueled patio appliances installed per manufacturer instructions are generally allowed; wood/charcoal fires require a burn permit and 25-foot clearance.

Sonoma County's Fire Safety Ordinance 6396 (codified at Chapter 13) treats both State Responsibility Area (SRA) parcels and all Local Responsibility Area parcels designated 'Very High Fire Hazard Severity Zone' (VHFHSZ) on the 2025 CAL FIRE maps as Wildland-Urban Interface (WUI). New construction and substantial remodels in those areas must meet California Building Code Chapter 7A and California Residential Code Chapter 337 ignition-resistant standards - including Class A roofs, ember-resistant vents, non-combustible siding, dual-pane tempered windows, and ignition-resistant decking. The Tubbs (2017), Kincade (2019), and Glass/Walbridge (2020) fires triggered substantial tightening of these requirements.

Sonoma County's water supply comes primarily from the Russian River system managed by Sonoma Water (Sonoma County Water Agency), which serves most cities and special districts in the county. Unincorporated areas are served by smaller mutual water companies, private wells, and county service areas. Sonoma County Code Chapter 25B requires private wells to meet permit and metering standards, and the county Board of Supervisors and Sonoma Water issue coordinated drought-stage declarations that trigger outdoor watering bans, day-of-week schedules, and well-pumping restrictions. The state's MWELO (Cal. Code Regs. Title 23, §490) applies to landscape projects of 500 sq ft or more in unincorporated Sonoma County.

Sonoma County protects native trees 6 inches in diameter or greater under the Tree Protection Ordinance (Code §26-88-010(m)), with stricter rules for heritage and landmark trees (Chapter 26D), oak woodlands (§26-67), and trees in riparian corridors (§26-65). The county adopted an updated tree ordinance on April 16, 2024.

Sonoma County does not set a numeric lawn height limit (e.g., '6 inches'). Instead, tall grass that creates a fire hazard is regulated under Chapter 13A (Hazardous Vegetation Abatement), and turf and irrigated grass area is capped on new and rehabilitated landscapes by the Water Efficient Landscape Regulations (County Code §7D3) under California MWELO.

Sonoma County Code Chapter 13A (Abatement of Hazardous Vegetation and Combustible Material) requires property owners to maintain defensible space and remove hazardous vegetation in unincorporated areas. Defensible space extends 100 feet from structures, with a 'lean, clean, and green' zone in the first 30 feet and a 'reduced fuels' zone from 30 to 100 feet.

In unincorporated Sonoma County, fence height is governed by Sec. 26-88-030 of the Sonoma County Zoning Code (Chapter 26, Article 88: General Exceptions and Special Use Standards). In residential and recreation/visitor-serving zoning districts (AR, RR, R1, R2, R3, and K), fences may not exceed 3 feet in height within the required front-yard setback and within 15 feet of a street corner, and 6 feet within side and rear yard setbacks. Permit Sonoma form PJR-133 (Fence Guidelines) explains the rules and the BPC-023 form details building-permit thresholds. There are no setback or height restrictions for fences in agricultural and resource districts (LEA, LIA, DA, RRD) or industrial/commercial districts (CO, LC, C1, C2, C3, CR, AS, MP, M1, M2, M3) except where the Scenic Resources (SR) combining district applies. All fences must be located at least 6 inches outside of public rights-of-way and easements. Heights above the setback limits may be allowed by Minor Use Permit. The Scenic Resources Combining District (Article 64) and Coastal Zone (Chapter 26C) impose additional siting, color, and materials standards on fences visible from designated scenic corridors like Highway 1, Highway 12, and the Russian River. Fences exceeding 7 feet (solid wood/concrete/metal/masonry) or 10 feet (any material) require a building permit under California Building Code Sec. R105.2 as adopted in Chapter 7.

Fences in unincorporated Sonoma County usually do not need a building permit, but several specific triggers require one. Under Permit Sonoma's PJR-133 (Fence Guidelines) and BPC-023 (Fence Requirements), no permit is needed for fences that comply with the height limits of Sec. 26-88-030 (3 ft front-yard / 6 ft side and rear in residential zones), do not exceed 7 feet of solid wood, concrete, metal, or masonry, and are not in a special combining district. A building permit is required for any fence exceeding 7 feet in solid construction or 10 feet in any material under California Building Code Sec. R105.2 as adopted in Chapter 7 of the County Code. A Minor Use Permit (or fence height exception under Sec. 26-92) is required to exceed the Article 88 height limits within required setbacks. Administrative Design Review is required for solid fences 3-6 feet in front-yard setbacks, all fences in the Scenic Resources (SR) combining district, and fences on commercial and industrial properties. A Coastal Development Permit may be required for fences in the Coastal Zone (CC suffix) under Chapter 26C. Fences along county roads must be at least 6 inches outside the public right-of-way; an encroachment permit from Sonoma County Public Infrastructure is required for any structure within a road right-of-way under Chapter 11.

Sonoma County operates a free Abandoned Vehicle Abatement Program through Permit Sonoma's Code Enforcement Division, authorized under California Vehicle Code Sec. 22660 and the County's Vehicle Abatement Ordinance codified in Chapter 18 of the Sonoma County Code (Motor Vehicles and Traffic). The program lets property owners in unincorporated Sonoma County have inoperative, wrecked, or dismantled passenger cars, pickups, SUVs, and vans removed from their property at no cost in exchange for written permission to dismantle the vehicle; the program does not service recreational vehicle storage yards or auto repair shops. On public roads, abandoned vehicles are addressed under California Vehicle Code Sec. 22651 (which authorizes tow within 72 hours of being parked) and Sec. 22669-22671 (which let public agencies remove vehicles that are inoperative or abandoned on a highway). Reports go through the SoCo Connect platform or by calling Code Enforcement at (707) 565-1992; the Sonoma County Sheriff's Office handles street-side enforcement on unincorporated county roads, and the California Highway Patrol handles state highways. The Abandoned Vehicle Abatement Service Authority (AVASA) - a separate countywide JPA funded by a $1 annual DMV registration surcharge under CVC Sec. 9250.7 - reimburses participating cities and the County for abatement costs.

In unincorporated Sonoma County, recreational vehicles and boats are treated under the Sonoma County Zoning Code (Chapter 26) and Chapter 18 (Motor Vehicles and Traffic). Personal RVs, trailers, and boats may be stored on a private residential parcel as a customary accessory use, but they cannot be occupied as a dwelling on residential land except under narrow exceptions in Sec. 26-88-066 (use of an RV by an ill, convalescent, or otherwise disabled friend or relative needing care from the property occupant) or on parcels with a KR/RV Combining District designation governed by Article 42 of Chapter 26. On-street parking in unincorporated areas is subject to the California Vehicle Code 72-hour rule (CVC Sec. 22651(k)) and Sonoma County's parallel parking limitations - an RV, trailer, or boat left on a public right-of-way for more than 72 hours without being moved is subject to citation and removal. Commercial RV storage yards, marinas, and dry-stack boat storage are land uses that require their own zoning approval (typically a use permit) and are not permitted as-of-right on residential lots. Park-model and travel-trailer occupancy as full-time housing is restricted to permitted mobile home parks, RV parks with the KR/RV combining designation, or properties operating under an approved temporary-use permit (often issued during post-fire rebuilding under Permit Sonoma's Rebuild program established after the 2017 Tubbs, 2019 Kincade, and 2020 Glass fires).

Sonoma County regulates driveways and off-street parking through three connected sources: Article 86 of Chapter 26 (Parking Regulations) of the Zoning Code, which establishes required off-street parking counts and design standards for new development; Chapter 11 (Roads, Streets, Bridges, and Sidewalks) of the County Code and the related encroachment-permit rules administered by Sonoma County Public Infrastructure / Transportation and Public Works, which govern any driveway connection to a county-maintained road; and the California Fire Code as adopted in Chapter 13 of the County Code, which sets driveway width, grade, surfacing, and turnaround standards for fire-apparatus access in the wildland-urban interface. New single-family dwellings must provide at least two off-street parking spaces (Sec. 26-86-010); ADUs generally require one space per unit but are exempt from that requirement in many circumstances under state law and Sec. 26-88-060. Driveways accessing county-maintained roads require an encroachment permit from Sonoma County Public Infrastructure under Chapter 11. Driveways serving parcels in CAL FIRE State Responsibility Areas or Very High Fire Hazard Severity Zones must meet Public Resources Code Sec. 4290 and California Fire Code Chapter 5 standards - minimum 20-foot unobstructed width for two-way access, 14-foot vertical clearance, all-weather surfacing supporting fire-apparatus loads, slopes generally not exceeding 16%, and turnarounds at the end of dead-end driveways longer than 150 feet. Parking on lawns or front yards may be restricted under Article 88 design standards depending on zone.

Sonoma County addresses commercial-vehicle parking through Chapter 18 (Motor Vehicles and Traffic) of the County Code, Article 86 (Parking Regulations) of Chapter 26 (Zoning), and Article 88 special use standards governing home occupations and accessory uses. Storage or extended parking of commercial trucks, tractor units, semi-trailers, dump trucks, tow trucks, taxicabs operating commercially, and similar vehicles on residentially zoned parcels is generally limited to vehicles owned and operated by a resident as part of their employment, parked in a non-front-yard location, and not used to conduct active commercial business on site. Operating a commercial trucking, repair, or storage yard from a residential parcel is not a permitted home occupation under Sec. 26-88-110 unless the parcel is in a commercial, industrial, or agricultural zoning district that allows the use, or a use permit has been obtained. Public-road parking of commercial vehicles in unincorporated Sonoma County is also subject to California Vehicle Code Sec. 22507.5 (which lets cities and counties prohibit parking of commercial vehicles over 10,000 pounds on residential streets between 10:00 p.m. and 6:00 a.m.) where the County has posted the appropriate signage.

Unincorporated Sonoma County does not have a stand-alone leaf-blower ordinance; gas-powered and electric leaf blowers are regulated only through the General Plan Noise Element 50 dBA daytime / 45 dBA nighttime property-line limits and Chapter 3, Article III (Noise Control). However, the City of Sonoma (within the County) has had one of California's earliest gas-leaf-blower bans since December 22, 2016 (Measure V), prohibiting gas-powered leaf blowers entirely and allowing electric leaf blowers only Monday through Saturday from 9:00 a.m. to 4:00 p.m. Statewide, California AB 1346 phases out new sales of gas-powered small off-road engines (including leaf blowers) starting January 1, 2024.

Construction noise in unincorporated Sonoma County is regulated under the General Plan Noise Element and Sonoma County Code Chapter 3, Article III (Noise Control). Permit Sonoma's standard practice and use-permit conditions require construction, grading, demolition, and exterior remodeling activity to occur between 7:00 a.m. and sunset (and not later than 7:00 p.m.) Monday through Saturday, with no construction permitted on Sundays or federal holidays except for owner-occupied minor repairs or declared emergencies. The 50 dBA daytime / 45 dBA nighttime Noise Element limits exempt construction noise during permitted hours but apply outside those hours.

Barking dogs and other persistent animal noise are governed by Sonoma County Code Chapter 5 (Animal Regulation Ordinance), Article X, Section 5-126 - Public Nuisances Prohibited. The ordinance prohibits any owner from permitting an animal to obstruct the reasonable and comfortable use of property by chasing vehicles, molesting passersby, barking, howling, or making other noise. Enforcement is handled by Sonoma County Animal Services (707-565-7100); the process requires written complaints from at least two households (or one household within 300 feet of the source) before an abatement order can issue.

Unincorporated Sonoma County does not use a single numeric quiet-hour ordinance; instead it enforces the Sonoma County General Plan Noise Element (adopted 2008, amended October 23, 2012) and Chapter 3, Article III - Noise Control of the Sonoma County Code, with the Sheriff and Permit Sonoma Code Enforcement responding to complaints. Under Table NE-2 of the Noise Element, non-transportation noise sources at the property line of a residential receiver may not exceed 50 dBA (L50) during daytime hours of 7:00 a.m. to 10:00 p.m. and 45 dBA (L50) during nighttime hours of 10:00 p.m. to 7:00 a.m., with higher short-duration limits of 55/60/65 dBA daytime and 50/55/60 dBA nighttime for the L25, L08, and L02 statistical percentiles.

Outdoor amplified music in unincorporated Sonoma County is one of the most heavily regulated activities in the County because of long-standing conflicts between wineries, event centers, and surrounding rural-residential neighbors. The Winery Events Ordinance amendments adopted by the Board of Supervisors on December 9, 2025 (taking effect June 9, 2026) impose a 1,600-foot setback from adjacent property for outdoor amplified music, a 625-foot setback for acoustic music, and a 450-foot setback for event parking, on top of the General Plan Noise Element 50 dBA daytime / 45 dBA nighttime property-line limits. Periodic special events are capped at 2,500 attendees. Non-winery amplified music is governed by Chapter 3, Article III (Noise Control) and use-permit conditions.

Sonoma County Code Chapter 26 (Zoning Regulations) is the controlling code for animal keeping. Farm animals are broadly permitted in the LIA, LEA, DA, RRD, AR, and RR districts subject to parcel-size limits, while the R1 single-family residential zone allows up to six hens housed in a rear-yard coop and no roosters or larger livestock.

Beekeeping is broadly permitted across Sonoma County's agricultural and rural-residential zones with no county-specific hive caps. All apiaries must be registered with the Sonoma County Agricultural Commissioner through California's BeeWhere program under California Food & Agricultural Code §§29040–29043.

Sonoma County has no breed-specific legislation. California Food & Agricultural Code §31683 prohibits any local ordinance from declaring a specific breed potentially dangerous or vicious. Sonoma County instead regulates individual dogs on a behavior basis under Chapter 5, Articles regulating potentially dangerous and vicious dogs.

Sonoma County Code Chapter 5, Section 5-115 prohibits dogs from running at large on public streets, public places, or private property of others. Dogs in public must be restrained by a substantial leash. Section 20-8 requires a maximum 6-foot leash and immediate control in all Sonoma County Regional Parks.

Home occupations in unincorporated Sonoma County are governed by Zoning Code Sec. 26-88-121, as amended by Ordinance No. 6363 (effective December 14, 2021). If the business complies with every operational standard, NO zoning permit is required. Non-compliant operations may be approved as Live/Work uses through a discretionary permit. The standards limit employees to household members, customer visits to 4 per day (max 2 at once) during weekday business hours, and floor area to 25% of the dwelling.

Unincorporated Sonoma County does not have a stand-alone juvenile-curfew ordinance applicable countywide. A 1997 proposal by the Board of Supervisors to impose an 11:00 p.m. weeknight and midnight weekend curfew on minors in unincorporated areas was debated but was not adopted as standing County code. Several Sonoma County cities have their own curfew ordinances (e.g., Santa Rosa Municipal Code Ch. 9-12, Petaluma Municipal Code 9.16, Sonoma Municipal Code), and California Welfare & Institutions Code Sec. 625.5 allows but does not require local curfew laws.

Sonoma County Regional Parks are open for day use 365 days a year from 7:00 a.m. to sunset, with parking lots and entry gates closing at sunset. Park policies are codified in Chapter 20 (Parks and Recreation) of the Sonoma County Code. Overnight stays are restricted to established campgrounds with reservations; amplified music is prohibited; alcohol is banned year-round at several specific parks (Larson Park, Healdsburg Veterans Memorial Beach, Guerneville River Park) and seasonally at Steelhead Beach, Sunset Beach, and Forestville River Access from Memorial Day through Labor Day.

Sonoma County operates under two separate Municipal Separate Storm Sewer System (MS4) NPDES permits - one issued by the North Coast Regional Water Quality Control Board for the Russian River basin and one by the San Francisco Bay Regional Water Quality Control Board for southern Sonoma County. Chapter 11 of the Sonoma County Code prohibits discharge of any pollutant (including muddy construction runoff) to the storm-drain system or waters of the state. Development and redevelopment projects must implement Low-Impact Development (LID) post-construction stormwater controls.

Sonoma County Code Chapters 11 and 11A require construction-grading permits and Erosion Prevention and Sediment Control plans for almost any ground-disturbing work. During the October 15 - May 15 wet season, no more than 1 acre or 20% of the permitted work area (whichever is greater) may have erodible soil exposed at any time, and best management practices (BMPs) must be functional whenever the National Weather Service forecasts a 30% or greater chance of rain within 24 hours - in any season. Sonoma's hillside and vineyard/orchard grading rules (Chapter 36 VESCO) add further restrictions on slopes over 10%.

Sonoma County Code Chapter 7B (Flood Damage Prevention) implements the National Flood Insurance Program inside the unincorporated county. New construction and substantial improvements within FEMA-mapped Special Flood Hazard Areas (the 100-year floodplain, including the F1 floodway and F2 floodplain zoning overlays) must elevate the lowest finished floor at least one foot above the Base Flood Elevation (BFE) and use flood-resistant materials below the BFE. The FEMA Russian River watershed maps were finalized July 31, 2024.

Unincorporated Sonoma County does NOT have a local rent control ordinance. The 2024 Residential Tenancy Protections Ordinance (Ord. 6496) added eviction protections but did not adopt a local rent cap. The only annual rent-increase cap covering most Sonoma County tenants is California's statewide Tenant Protection Act (AB 1482), codified at Cal. Civ. Code § 1947.12, which limits increases to 5% + the regional CPI, with a 10% hard ceiling.

On September 17, 2024, the Sonoma County Board of Supervisors adopted Ordinance No. 6496, the Residential Tenancy Protections Ordinance, which applies to rental units in unincorporated Sonoma County. The ordinance augments the statewide California Tenant Protection Act (AB 1482, Cal. Civ. Code § 1946.2) by extending just-cause protections from day one of any covered tenancy, expanding coverage to income-restricted housing, narrowing the rent-nonpayment trigger, and increasing no-fault relocation payments.