Building permits, zoning and septic rules in Duchesne County, Utah

Yes. Unincorporated Duchesne County requires a building permit for any building designed or intended for human occupancy, regardless of size¹. Incorporated Altamont, Tabiona, Duchesne, Roosevelt and Myton use separate building departments or inspectors¹. An accessory storage shed on a parcel with an established dwelling can avoid a permit only when it is single story and 200 square feet or less; a shed on a vacant parcel needs a permit regardless of size⁷. A qualifying agricultural structure used solely for agriculture and not for human occupancy may be exempt, but plumbing, electrical and mechanical permits can still apply, subdivision acreage conditions matter, and zoning setbacks still must be met¹¹. A sole owner may use Utah's owner-builder exemption for personal, noncommercial work, but a new home must be the owner's only residential structure that year and the owner may not have built more than 3 residential structures in the preceding five-year period⁶.

The Duchesne County Department of Building Safety is at 734 North Center Street, Duchesne, UT 84021, reachable at (435) 738-1150 or building@duchesne.utah.gov¹². Unincorporated Duchesne County applies the International Building Code and the International Residential Code as amended, and detached one- and two-family homes follow the residential code¹³. Building permit fees are based on the estimated construction cost, a 1% state surcharge applies to every issued building permit, and plan review adds 35% to 65% of the permit fee⁶. The county offers an online application and PDF forms, including a permit packet and checklist⁶. Construction documents must be dimensioned and drawn on suitable material, while an approved electronic submission must be a PDF⁶. A permit expires if work does not begin within 180 days or stops for 180 days after it begins; a written request based on circumstances beyond the permit holder's control can support an extension of up to 180 days⁶. County-permitted work is inspected against the approved plans, and final approval plus a certificate of occupancy are required before a completed building is occupied or used⁶.

Yes. Duchesne County's zoning title applies to land, buildings and premises in the unincorporated area shown on the official zoning district map⁴. The county publishes those districts in the Tax Parcel Viewer zoning layer, and a use may be permitted outright, conditional or restricted depending on the district². Minimum lots are 10 acres in A-10, 5 acres in A-5, 2.5 acres in A-2.5, 1 acre in R-1 and 0.5 acre in R-1/2⁵. The listed districts use 30-foot front and rear setbacks, while side-yard standards vary¹⁴. Residential and agricultural districts cap building height at 40 feet; commercial and industrial districts allow 50 feet, and exceeding 40 feet requires conditional-use approval¹⁴. Contact Community Development to verify the parcel's mapped district and proposed use¹⁵.

TriCounty Health Department is the local onsite-wastewater authority for Duchesne County: its environmental health staff reviews system plans, issues construction permits and inspects installations³. An application requires a site assessment, drinking-water proof, a floor plan, fees and a detailed system drawing¹⁶. TriCounty must conduct the final inspection before issuing the operating permit, and the system must remain exposed enough to verify construction against the approved plans¹⁶. A state-approved sewer connection is required when TriCounty finds a sewer accessible and within 300 feet of the property, with another 150 feet counted for each proposed residential lot or unit¹⁷. Only about 9.7% of county soils rate free of severe limitations for a conventional drain field, so complete the site assessment before assuming a standard system will work¹⁸.

Unincorporated Duchesne County does not allow an RV to serve as a primary residence unless it is in an approved RV park⁸. The Community Development Administrator may grant an exception for no more than 1 year when the RV occupancy accompanies a valid building permit for a permanent dwelling and appropriate water and wastewater facilities are provided⁸. Do not assume occasional camping is allowed on every parcel: campground use is treated differently across the county's zoning districts, and the available rule does not answer informal camping on private land². Accessory dwellings are permitted in A-10/A-5, A-2.5 and R-1, require conditional-use approval in R-1/2, and are prohibited in commercial and industrial districts¹⁰. A tiny home is treated like any other building designed or intended for human occupancy: it needs a building permit regardless of size, and zoning, water and wastewater requirements still apply⁷. The county does not name a separate tiny-home category, so ask Community Development how a specific tiny home would be classified before buying or placing one¹⁵.

1. Confirm the parcel's mapped zoning district, allowed use, minimum lot size, setbacks and height limit with Community Development before designing the house^2,5,14.

1. Establish an approved culinary-water source. If no public system serves the building, obtain private-well approval from the Utah Division of Water Rights and TriCounty Health Department; the state Start Card serves as the well-construction permit^9,17.

1. Ask TriCounty whether sewer connection is required; if not, complete the site assessment and obtain the onsite wastewater permit^3,17.

1. Obtain fire-plan approval, then submit the building application and construction documents to Building Safety^1,6.

1. Obtain the applicable county-road or state-highway access permit^19,20.

1. Complete building and septic inspections, then obtain final approval and the certificate of occupancy before moving in^6,16.

Confirm legal access before committing: Duchesne County warns that a parcel is not guaranteed to have legal access, and Community Development can provide a map of nearby roads⁷. Dividing land into 2 or more lots generally requires county approval, and a minor subdivision of up to 4 parcels must meet lot-size, sanitary approval, legal-access and culinary-water requirements²¹. Check flood status early because development in the unincorporated county's 1% annual-chance floodplain requires a floodplain permit²². A commercial short-term rental in the A-2½ or A-5 district requires conditional-use approval, a business license, health approvals and a building inspection before guests occupy it²³. Check soils and water together: only about 9.7% of county soils rate free of severe limits for a conventional septic drain field, and a water-production well needs a state water right and Start Card^9,18.