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

Yes. Unincorporated Fresno County requires a building permit for the erection, construction, enlargement, alteration, repair, moving, improvement, demolition or conversion of a building or structure unless a specific exemption applies¹. Examples include a detached tool shed up to 120 square feet, a fence up to 7 feet, and a retaining wall up to 4 feet unless it supports a surcharge or impounds specified liquids¹. A detached, one-story Group U accessory structure may qualify at no more than 240 square feet of floor or column area, 380 square feet of roof area, and 10 feet of wall or post height; claiming that exemption still requires a Citizens Portal filing, site plan, elevation, operational statement, contractor or owner-builder information, waste plan, and applicable fees¹. This is not a blanket agricultural-building exemption¹. Fresno County's Title 15 adopts the California Building Code by reference, and the 2025 California Building Standards Code applies to permit applications dated January 1, 2026 or later^8,9. Standard-plan permits issued between January 1, 2023 and December 31, 2025 stay valid for 12 months from issuance; if construction has not started by then, the permit falls under the 2025 code⁸.

Fresno County Development Services — Building & Safety handles building permits, plan checks, and inspections for unincorporated Fresno County at 2220 Tulare Street in Fresno¹⁰. For permit and plan-check questions call (559) 600-4570; Building Inspection is (559) 600-4560, and the 24-hour inspection-request line is (559) 600-4131¹⁰. Inspection requests must be placed by 2:30 p.m. on the business day before the requested inspection day¹¹. For a qualifying residential project, Fresno County must determine completeness within 15 days, then complete project review within 30 days for 25 units or fewer or 60 days for 26 units or more¹². County building-permit fees increased by 3% on July 1, 2026; budget from the current Master Schedule of Fees¹⁰.

Yes. Fresno County's Zoning Ordinance regulates land use in the unincorporated area under the General Plan and applicable specific plans². The county publishes the complete ordinance plus separate materials for zones, allowable uses, and zone-specific standards¹³. Inside city limits, Fresno¹⁴, Coalinga¹⁵, Parlier¹⁶, Mendota¹⁷ and Huron¹⁸ set their own zoning, and the same five issue their own building permits^{5,19,20,21,22}. The county's rules here cover unincorporated land, so confirm the parcel's jurisdiction first. Septic and well permits stay with county Environmental Health²³. Lot size, setbacks, and height all depend on the district^24,25. For example, the main-structure limit without discretionary approval is 25 feet in R-1, 35 feet in R-2, 20 feet in R-2-A, 40 feet in R-3, and 20 feet in R-3-A^2,26. We could not confirm a general minimum floor area for an ordinary house; the SRO size rule is specialized and does not answer that question². Fresno County allows ADUs only on eligible parcels and prohibits using an RV or trailer as an ADU²⁷. A new ADU on a septic property needs its own separate septic system, and an ADU on a sewered property may share the main house's waste piping if it is large enough or tie in separately²⁸. The county page also states that ADUs are currently not allowed within low water areas²⁸.

Fresno County Environmental Health regulates septic design, installation, operation, and wastewater dispersal in unincorporated Fresno County under the county's Local Agency Management Program³. During a site evaluation, county staff inspect with the qualified professional, log soil test holes, and make an initial suitability determination³. Before inspection, a septic tank must be filled with water to the flow line, its seams and joints must remain exposed except at the bottom, and the system must pass a flow test³. Only 5.8% of Fresno County soils have no severe limits for a conventional drain field, so establish feasibility early²⁹. Special sewage-dispersal systems for minor, limited, or temporary uses need prior county approval; Fresno County's rule does not establish unrestricted approval for a composting toilet or another specific off-grid system³⁰. Environmental Health also issues well-construction permits in unincorporated areas, although operating a completed private well needs no separate permit⁷. Reach the office at 1221 Fulton Street, 3rd Floor, Fresno, CA 93775, phone (559) 600-3357²³.

A tiny home can be legal in unincorporated Fresno County only on an approved site and in a form that complies with the applicable rules¹. If it is the first dwelling, the property must comply with the California Subdivision Map Act and Fresno County zoning, grading, and building rules¹. A chassis-based tiny home must have axles, contain no more than 400 square feet excluding loft space, and qualify as an RV, commercial coach, or park trailer; a non-chassis unit must be permanently affixed and meet applicable building or factory-built-housing standards¹. Ask Fresno County Zoning whether the parcel's district allows the proposed installation^1,10. Fresno County defines RV-park spaces as temporary occupancy in a district allowing recreational uses; those spaces may also serve tent campers⁶. The county's RV-park ordinance does not establish a general authorization for long-term RV occupancy on private land outside an RV park⁶, so do not plan on living in an RV on a bare parcel. We could not confirm whether any exception exists for temporary camping on private land, so ask Fresno County Zoning before buying or building around either use¹⁰.

1. Confirm the parcel's jurisdiction, zoning district, allowable use, lot size, setbacks, and height standard with Fresno County Zoning^10,13.
2. Check floodplain status; work in a Special Flood Hazard Area requires a building and/or grading permit and licensed professionals³¹.
3. If public sewer is unavailable, complete Environmental Health's septic site evaluation before fixing the house location^3,23.
4. If the project needs a well, have a licensed well driller obtain the well-construction permit from Environmental Health^7,23.
5. Choose a licensed contractor or owner-builder route; an owner-builder must complete the county form, verify the owner's signature, and accept legal and financial responsibility⁴.
6. Submit the building-permit application and use the current fee schedule^10,12.
7. Schedule required inspections; requests must be placed by 2:30 p.m. on the prior business day^10,11.
8. Apply for the certificate of occupancy with the building-permit application and do not occupy the building before issuance³².

Start with septic feasibility: only 5.8% of Fresno County soils have no severe limits for a conventional drain field, so a site evaluation can materially affect the build plan and budget²⁹. Terrain varies sharply: 38.6% of the county is at a 15% grade or less, 31.8% is wooded, and federal land covers 40.5%²⁹. Severe drought occurs in about 40.3% of years, and projections show roughly 34.1 days annually at or above 100°F by mid-century²⁹. If a purchase depends on splitting land, new parcels must meet the minimum parcel size in the zoning ordinance and the county's Division of Land rules³³. A Tentative Tract Map generally applies to 5 or more lots, requires a Planning Commission hearing, and has at least a 90-day processing estimate plus a 15-day appeal period³⁴. Farmland averages about $16,378 per acre, a typical home value is about $411,442, and the median property-tax bill is $2,704 per year at an effective rate near 0.7%²⁹. The nearest city of 100,000 or more is about 6 miles from the county's center²⁹.