Sonoma County · Building on your lot

Building on your lot in Sonoma County

In unincorporated Sonoma County, the county code sets its own limits on fences, accessory buildings, home businesses, oversized vehicle parking, pools and tree removal. Fence limits depend on the yard and whether the fence is near a street corner.

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Key points

Fence height: Listed zones: use permit for fences over 3 feet in front yards or near corners, over 6 feet in side or rear yards.
Home businesses: County rule: a home business may use at most 25% of the dwelling, or 500 square feet of a garage or accessory structure.
Customer visits: County rule: at most 4 customers a day and 2 at a time, weekdays 8 a.m. to 6 p.m.; only residents may be employed.
Accessory buildings: County rule: on vacant parcels under 2 acres in listed zones, accessory buildings must be under 120 square feet, unless serving existing agriculture.
Oversized vehicles: County rule: oversized vehicles, boats and trailers may park on county roads at most 6 consecutive hours, then must move at least 72 hours.
Large trees: County rule: removing redwoods over 48 inches or oaks and other hardwoods over 36 inches in diameter needs a use permit, unless exempt.

Each rule below is marked Sonoma County code or CA state law and links to the section it comes from (checked October 2026). General information, not legal advice.

Sonoma County's code applies in the unincorporated areas of the county. Cities in Sonoma County have their own codes and their own pages.

Fences and walls

Sonoma County code What Sonoma County's code adds
Corner visibility	Over 3 feet needs a use permit within 15 feet of street corners or in corner-lot exterior side yards. Applies: Noncoastal zoning; AR, RR, R1, R2, R3 or K districts. § 26-88-030 · code text (a) In an AR, RR, R1, R2, R3 or K district, no fence shall hereinafter be constructed to exceed six feet (6′) in height within any required side yard to the rear of the front line of any dwelling, or along any rear property line, nor to exceed three feet (3′) in height within any required front yard nor within fifteen feet (15′) of the street corner nor within any required exterior side yard on any corner lot, without first securing a use permit in each case. Over 3 feet needs a use permit within 15 feet of street corners or in corner-lot exterior side yards. Applies: Coastal zoning; AR, RR, R1, R2 or PC districts. § 26C-322 · code text (a) In an AR, RR, R1, R2, or PC district, no fence shall hereinafter be constructed to exceed six feet (6′) in height within any required side yard to the rear of the front line of any dwelling, or along any rear property line, nor to exceed three feet (3′) in height within any required front yard nor within fifteen feet (15′) of the street corner nor within any required exterior side yard on any corner lot, without first securing a use permit in each case.
Permit	Use permit above 6 feet on rear lines or side yards behind the home; above 3 feet in front yards. Applies: Noncoastal AR, RR, R1, R2, R3 or K districts; 3-foot limit also within 15 feet of street corners and corner-lot exterior side yards. § 26-88-030 · code text (a) In an AR, RR, R1, R2, R3 or K district, no fence shall hereinafter be constructed to exceed six feet (6′) in height within any required side yard to the rear of the front line of any dwelling, or along any rear property line, nor to exceed three feet (3′) in height within any required front yard nor within fifteen feet (15′) of the street corner nor within any required exterior side yard on any corner lot, without first securing a use permit in each case. Use permit above 6 feet on rear lines or side yards behind the home; above 3 feet in front yards. Applies: Coastal AR, RR, R1, R2 or PC districts; 3-foot limit also within 15 feet of street corners and corner-lot exterior side yards. § 26C-322 · code text (a) In an AR, RR, R1, R2, or PC district, no fence shall hereinafter be constructed to exceed six feet (6′) in height within any required side yard to the rear of the front line of any dwelling, or along any rear property line, nor to exceed three feet (3′) in height within any required front yard nor within fifteen feet (15′) of the street corner nor within any required exterior side yard on any corner lot, without first securing a use permit in each case.

Sheds, garages and other accessory structures

Sonoma County code What Sonoma County's code adds
Size or lot coverage	Accessory buildings must be under 120 square feet. Applies: Vacant parcels under 2 acres in LIA, LEA, DA, RRD, AR, RR and PC zones; not buildings serving an existing agricultural use. § 26-16-080 · code text On vacant parcels less than two (2) acres, accessory buildings may only be constructed if less than one hundred twenty (120) square feet or as incidental to an existing agricultural use.

Running a business from home

Sonoma County code What Sonoma County's code adds
Space used	No more than 25% of the home's total floor area. Applies: When using part of the home; the whole business must use only one of the listed locations. § 26-88-121 · code text A portion of the dwelling which does not exceed more than twenty-five percent (25%) of the total floor area of the dwelling; No more than 500 square feet. Applies: When using a garage; the whole business must use one listed location and may not displace required parking. § 26-88-121 · code text A garage or portion thereof, (up to a maximum of five hundred (500) square feet) which does not displace any required parking; No more than 500 square feet. Applies: When using a detached accessory structure; the whole business must use only one of the listed locations. § 26-88-121 · code text A detached accessory structure or portion thereof (up to a maximum of five hundred (500) square feet).
Customer visits	No more than 4 customers or clients per day. Applies: Per home, for any service or product; visits 8 a.m.-6 p.m. Monday-Friday, excluding state and federal holidays. § 26-88-121 · code text Not more than four (4) customers or clients shall be allowed to visit the dwelling for any service or product during any one (1) day, nor more than two (2) customers or clients at any one (1) time. No more than 2 customers or clients at one time. Applies: Per home; visits 8 a.m.-6 p.m. Monday-Friday, excluding state and federal holidays. § 26-88-121 · code text Not more than four (4) customers or clients shall be allowed to visit the dwelling for any service or product during any one (1) day, nor more than two (2) customers or clients at any one (1) time. 8:00 a.m. to 6:00 p.m., Monday to Friday; none on state and federal holidays. Applies: Customer visits and deliveries. § 26-88-121 · code text Customer visits and deliveries shall be limited to the hours of 8:00 a.m. to 6:00 p.m. Monday through Friday, and shall not occur on state and federal holidays.
Employees	Only residents of the home can be employed. § 26-88-121 · code text No person shall be employed in the home occupation other than residents of the dwelling.
Businesses not allowed	Adult entertainment activities/businesses; animal hospitals and clinics; pet care services such as grooming, doggie day cares or kennels; automotive and other vehicle sales, repair, services, painting, storage, or upholstery; boatmaking; commercial cabinet or furniture making, furniture refinishing/antique restoration and sales; dismantling, junk, scrap, or storage yards; food processing, canning, baking, catering, or motorized mobile food vendors; gun and weapon sales or repairs and gunsmithing; hair salons, day spas, and other uses generating higher water and sewer demands or higher customer visits; uses involving medical procedures; uses requiring hazardous or toxic materials, except specified small quantities; uses requiring explosives or highly combustible materials; uses triggering ADA-related building modifications or a change of occupancy classification; welding, machine shop operations, or metal fabricating; other uses similar in impact as determined by the director § 26-88-121 · code text (b) Limitations on Use. The following business activities are prohibited as home occupations: (1) Adult entertainment activities/businesses; (2) Animal hospitals and clinics; pet care services such as grooming, doggie day cares or kennels of any size; (3) Automotive and other vehicle sales, repair, services, painting, storage, or upholstery, or the repair of engines, including automobiles, boats, motorcycles, trucks, or recreational vehicles; (4) Boatmaking; (5) Commercial cabinet or furniture making, furniture refinishing/antique restoration and sales; (6) Dismantling, junk, scrap, or storage yards; (7) Food processing, canning, baking, etc., including catering, or motorized mobile food vendors such as coffee carts or taco trucks; (8) Gun and weapon sales or repairs, gunsmithing; (9) Hair salons, day spas, and other uses which generate higher water and sewer demands, and higher customer visits; (10) Uses which involve medical procedures; (11) Uses that require the handling of any hazardous (including biologically hazardous) or toxic materials, substances or wastes (as defined by California or federal law), except for small, nonreportable or unregulated quantities that are used in woodworking, painting, or photography, or in the making of jewelry, ceramics, pottery, and sculpture; (12) Uses that require explosives or highly combustible materials; (13) Uses that may trigger building modifications to meet California Building Code requirements related to Americans with Disability Act (ADA) or such that a change of occupancy classification is required; (14) Welding, machine shop operations, or metal fabricating; (15) Other uses that the director determines to be similar in impact to those listed above.

RV and boat parking

Sonoma County code What Sonoma County's code adds
Size limit	At least 24 feet long, 90 inches high or 96 inches wide: no parking over 6 consecutive hours. Applies: Vehicles, boats or trailers on county highways and rights-of-way; trailers, trailer coaches, buses and RVs count as oversized at any size. § 18-3.10 · code text 24 feet in length
Parking on the street	Up to 48 consecutive hours, only for loading or unloading. Applies: Moving vans, RVs or other oversized vehicles actively loading or unloading at the business or home right next to them. § 18-3.10 · code text Moving vans, recreational vehicles, or other oversized vehicles actively being used for loading or unloading of items from the business or residence immediately adjacent to where it is parked, for a period of no more than forty-eight (48) hours consecutive hours for the purpose of loading or unloading only. No more than 6 consecutive hours; then the vehicle must move away for at least 72 hours. Applies: Oversized vehicles on county roads; deliveries, loading up to 48 hours, emergency repairs under 24 hours, and some other uses excepted. § 18-3.10 · code text No person shall stop, park, or leave standing on any county highway or county right-of-way any vehicle defined in this section for a period longer than six (6) consecutive hours

Solar panels and EV chargers

Sonoma County code The building official approves and issues all permits when the application is complete and meets the checklist. No more than 15 feet high, unless a structural engineer shows it meets public safety standards.

All 5 Sonoma County rules on solar panels and ev chargers, with the code text and the state law underneath →

Tree removal

Sonoma County code County rule: removing redwoods over 48 inches or oaks and other hardwoods over 36 inches in diameter needs a use permit, unless exempt.

All 13 Sonoma County rules on tree removal, with the code text and the state law underneath →

Swimming pools

Sonoma County code What Sonoma County's code adds
Pool barrier	The outside surface must have no protrusions or cavities that could serve as handholds or footholds. Applies: Applies to private pools built before June 1, 1998 that use an enclosure. § 7-15 · code text An outside surface free of protrusions, cavities or other physical characteristics that would serve as handholds or footholds that could enable a child below the age of five (5) years to climb over. No more than 2 inches between the ground and the bottom of the enclosure. Applies: Private pools built before June 1, 1998 with an enclosure; single-family pools over 18 inches deep; some spas and facilities excluded. § 7-15 · code text A maximum vertical clearance from the ground to the bottom of the enclosure of two (2″) inches; Gaps must not let a sphere 4 inches or larger pass through. Applies: Private pools built before June 1, 1998 with an enclosure; single-family pools over 18 inches deep; some spas and facilities excluded. § 7-15 · code text Gaps or voids, if any, do not allow passage of a sphere equal to or greater than four (4″) inches in diameter;
Barrier height	At least 60 inches high. Applies: Private pools built before June 1, 1998 with an enclosure; single-family pools over 18 inches deep; some spas and facilities excluded. § 7-15 · code text A minimum height of sixty (60″) inches;
Equipment and alarms	Exit alarms must be at least 80 DB, measured 10 feet from the alarm. Applies: Applies when home doors opening directly to the pool have exit alarms; single-family pools over 18 inches deep. § 7-15 · code text the exit alarms shall produce sounds at or exceeding sound pressure of eighty (80) DB at ten (10) feet distance from the alarm emitter. The power safety cover control must be at least 60 inches above the ground or floor. Applies: Applies to pools with a power-operated safety cover; single-family pools over 18 inches deep. § 7-15 · code text the control for the pool cover shall be mounted at least sixty (60) inches above grade or above the floor;
Gates	Gates open away from the pool and self-close, with a self-latching device at least 60 inches above ground. Applies: Private pools built before June 1, 1998 with an enclosure; single-family pools over 18 inches deep; some spas and facilities excluded. § 7-15 · code text Any access gates through the enclosure open away from the swimming pool, and are self-closing with a self-latching device placed no lower than sixty (60) inches above the ground;
Permit	Yes, a building permit; plans must be prepared by a California-licensed civil or structural engineer. Applies: Applies to private pools; single-family pools over 18 inches deep; some spas and facilities excluded. § 7-15 · code text No building permit shall be issued for any private swimming pool, except in compliance with this section and Article 2.5 of Chapter 5 of Part 10 of Division 104 of the California Health and Safety Code

Other Sonoma County rules on this

Sonoma County's code also has these chapters. We have not summarized their values on this page yet; read them in the library.

Farm animal limits and backyard hens (§ 26-18-080)

Who this affects

HomeownersContractorsDesigners

Frequently asked questions

How tall can a fence be in Sonoma County?

Listed zones: use permit for fences over 3 feet in front yards or near corners, over 6 feet in side or rear yards.

How big can a shed or accessory building be in Sonoma County?

County rule: on vacant parcels under 2 acres in listed zones, accessory buildings must be under 120 square feet, unless serving existing agriculture.

Can I run a business from my home in Sonoma County?

County rule: a home business may use at most 25% of the dwelling, or 500 square feet of a garage or accessory structure. County rule: at most 4 customers a day and 2 at a time, weekdays 8 a.m. to 6 p.m.; only residents may be employed.

Can I park an RV or boat at my home in Sonoma County?

County rule: oversized vehicles, boats and trailers may park on county roads at most 6 consecutive hours, then must move at least 72 hours.

What are the pool fence and setback rules in Sonoma County?

Sonoma County's code: The outside surface must have no protrusions or cavities that could serve as handholds or footholds. (Applies to private pools built before June 1, 1998 that use an enclosure.) (§ 7-15); No more than 2 inches between the ground and the bottom of the enclosure. (Private pools built before June 1, 1998 with an enclosure; single-family pools over 18 inches deep; some spas and facilities excluded.) (§ 7-15).

General information, not legal advice.

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