Building permits, zoning and land rules in Yolo County, California

Yes. In unincorporated Yolo County, an owner or agent must get a building permit before constructing, enlarging, altering, moving or demolishing a structure¹. California's Title 24 building standards apply, while county zoning, setbacks and other local land-use requirements still govern the parcel¹¹. The 2025 California Building Standards Code applies to permit applications dated on or after January 1, 2026¹².

A qualifying agricultural building in the A-N or A-X zone can avoid a building permit if it is not inhabited, used to process or pack products, or open to the public and meets all zoning, fire, sanitation and construction conditions⁷. Plumbing and electrical work still require separate permits⁷. California's owner-builder exemption concerns contractor licensing; it does not waive Yolo County's required building permit^1,8.

Yolo County Building Inspection Services, part of the Department of Community Services, is at 292 West Beamer Street in Woodland; call 530-666-8037 or email building.division@yolocounty.gov¹³. Submit building-permit applications through the Yolo Builds online portal¹³. The Planning Division, (530) 666-8775, and Environmental Health, (530) 666-8646, are in the same building, so one trip can cover zoning, septic and building questions^14,15.

County zoning covers only unincorporated Yolo County, so a parcel inside a city needs that city's zoning and building guidance². Yolo County Environmental Health remains the county contact for septic systems³. Building-permit and plan-check fees depend on project valuation; the published schedule lists a $56 issuance fee and single-family/garage plan review at 65% of the building-permit fee, with other applicable charges separate¹⁶. Ask Building Inspection Services for the current fee total for your plans^13,16.

Yes. Yolo County zoning covers the unincorporated area; incorporated cities administer their own rules². Title 8 contains the county zoning regulations and subdivision rules, and the Planning Division's GIS map identifies a parcel's district^2,14,17.

RR-5 requires 5 acres and RR-2 requires 2 acres; a rural parcel without public water or wastewater also needs at least 2 acres for a new building permit¹⁰. In RR-5 and RR-2, the front setback is 20 feet from the property line or 50 feet from the roadway centerline, whichever is greater, with 25-foot rear and 10-foot side setbacks¹⁰. Other residential districts use different standards, so confirm the zoning before drawing a site plan^10,14. ADUs are permitted in unincorporated residential zones if they meet the county's standards¹⁸. RR-5 has no primary-dwelling size limit in its residential development table, but that does not establish a separate tiny-home occupancy approval¹⁰.

Where community sewer connection is unavailable, Yolo County allows approved onsite septic treatment; alternative systems may require annual operating permits and service-provider reports³. Yolo County Environmental Health requires a septic installation permit for a new or replacement system, and work cannot start until the permit is issued¹⁹. A new-system permit will not be issued without a building permit, and the septic permit must be finalized before the building permit can be finalized¹⁹.

The process starts with a site evaluation and soils profile²⁰. Hire a septic qualified professional, submit the request and fee, and schedule Environmental Health at least 48 hours ahead⁶. The evaluation uses at least two pits dug to at least eight feet, covering the primary and replacement areas⁶. Only 2.5% of Yolo County soils avoid severe limits for a conventional drain field, so an engineered alternative system may be necessary^5,20. In developed areas, a parcel with sewage and a property line less than 200 feet from a sewer collector must be provided sewer service²¹.

An RV cannot be used as a temporary or permanent dwelling on residentially zoned property in unincorporated Yolo County unless the Planning Director approves it while a home is under construction⁹. Private-property camping is different: you may camp on your own land, with the owner, or with the owner's written consent carried by the camper and shown to a peace officer on demand, but county zoning and State Health Code requirements still apply²². Camping on county-owned or county-maintained public property is prohibited unless the Park and Recreation Director permits it within a park²³.

We could not confirm a separate Yolo County occupancy category for a tiny home, so ask Planning which recognized housing type and zoning standards would apply¹⁴. In unincorporated Yolo County, manufactured homes may substitute for stick-built residences in agricultural zones and in other zones where allowed or permitted, subject to siting and development standards²⁴. Installation requires a Community Services permit, current state housing approval and compliant utilities; newly installed homes generally require fire sprinklers²⁵. A temporary mobile home or commercial coach during construction requires a building permit for the permanent building and may stay for 6 months, with one additional 6-month renewal if substantial progress and likely completion justify it²⁴.

1. Look up the parcel's zoning and confirm its allowed use, minimum lot area and setbacks with Planning at (530) 666-8775^10,14.
2. Check the flood map; development in a special flood-hazard area requires a county Development Permit before work begins²⁶.
3. Hire a septic qualified professional and schedule the site evaluation with Environmental Health⁶.
4. Coordinate the building and septic installation applications; a new-system permit requires a building permit, and septic approval must be final before the building permit is final¹⁹.
5. Get an Environmental Health permit if the project needs a well⁴.
6. Get a Public Works encroachment permit for driveway construction in a county road right-of-way²⁷.
7. Submit building plans through Yolo Builds¹³.
8. Start work before the permit expires and avoid suspending or abandoning it for 180 days⁷.

Yolo County has had severe drought in 42.2% of years, and rain averages 21.4 inches a year⁵. Installing, modifying or abandoning a well requires an Environmental Health permit, and the well needs final inspection before use⁴.

Check the flood map too: construction or other development in a mapped special-flood-hazard area requires a Development Permit before work starts²⁶. Public Works requires an encroachment permit for driveway work in a county road right-of-way; ask Public Works or Caltrans which access approval applies to a homesite on a state road^27,28.