Building permits, zoning and land rules in Millard County, Utah

Residential construction in unincorporated Millard County requires a building permit, and the county enforces adopted construction codes¹. Regulated alterations, repairs, moves, demolition, occupancy changes, and gas, mechanical or plumbing installations also require approval before work begins¹. The county building checklist says every residential dwelling in unincorporated Millard County requires a conditional-use permit recorded with the deed¹.

An agricultural structure used solely for agriculture and never for human occupancy may qualify for an exemption, but Millard County requires an exemption application and a setback inspection before construction or concrete placement¹. Plumbing, electrical and mechanical permits may still be required; acreage and location restrictions also apply¹. The exemption expires if construction has not begun within 6 months, and converting an exempt barn to another use requires a new permit and documented engineering and testing¹.

Inside Town of Lynndyl, the town handles building permits; onsite wastewater permits remain with Central Utah Public Health Department^3,10.

Millard County Building Inspection handles building permits, code enforcement and inspections for unincorporated projects; call 435-864-1400 or use the Delta office listed above^1,11. The permit holder or contractor must request required inspections, and a certificate of occupancy follows approved inspections¹¹. Utah also provides a third-party inspection route: after requesting inspection and notifying the local regulator of the firm, the applicant can have the firm inspect and submit its final report, after which the regulator must promptly issue the certificate or completion letter¹².

Planning and Zoning handles land-use applications¹³. The published schedule lists a $20 residential P-1 land-use permit, a $165 C-1 conditional-use permit and no fee for an agricultural building-permit exemption; these are separate from building-construction permit fees and are subject to change¹⁴. Ask Planning and Zoning which residential approval applies, because the building checklist calls for a recorded conditional-use permit¹.

Millard County zoning governs unincorporated land, outside municipal boundaries^2,15. Town of Lynndyl administers its own zoning inside town limits; onsite wastewater approval remains with Central Utah Public Health Department^3,10. Uses on unincorporated land may be permitted, conditional or prohibited by district, and an unlisted use is prohibited².

Campgrounds are conditional in some districts and prohibited in others, but that rule does not answer whether one RV may be occupied on a private parcel⁵. Minimum lot size for a primary building is 20 acres in the RF and AG-20 districts and 1 acre in the AG and R1 districts¹⁶. Required front yards are 35 feet in RF, AG-20 and AG and 25 feet in R1; side yards are 30 feet in RF and AG-20 and 15 feet in AG and R1; rear yards are 40 feet in all four¹⁶. In the AI, HC, LI and HI districts, lot size and yards are set case by case through site-plan approval¹⁶.

Millard County’s manufactured-home definition includes a 400-square-foot on-site threshold or alternative traveling-mode dimensions, and requires a permanent foundation and building-code compliance⁵. We could not confirm site-built minimum size, lot coverage or height limits; ask Planning and Zoning¹³.

Central Utah Public Health Department administers onsite wastewater permits in Millard County, and no part of a system may be constructed before the department issues its construction permit^3,4. The application package calls for an application, soil classification, site plan, system design, and—when applicable—an operation and maintenance plan or contract⁴.

Only 15.3% of mapped soils avoid a “very limited” rating for a conventional drain field, so soil evaluation should happen early rather than after the house site is fixed¹⁷. Public-sewer connection is required when available and practicable; otherwise an adequate onsite or otherwise accepted wastewater system is required¹⁸. We could not confirm a general pre-backfill inspection rule from the available county material, so ask the health department about inspection stages when applying.

Millard County's campground rule does not create blanket permission to live in an RV on private land. Campgrounds are conditional uses in RF, AG-20, AG, and HC districts and prohibited in AI, R1, LI, and HI districts⁵. The available county rule does not state a maximum stay for an authorized campground⁵. Gunnison Bend Park is a separate case: overnight camping and parking are prohibited within the park¹⁹.

Tiny-home permission also depends on classification and land-use approval. Utah's RV-park rule allows a qualifying tiny house in an RV park under certification, code, and local-ordinance conditions, but outside a park the answer depends on local treatment as a primary dwelling, accessory dwelling, modular unit, or manufactured home⁶. In one documented case, the Millard County Planning Commission approved a permanent tiny house as an accessory dwelling unit through a C-1 conditional-use permit, so approval is handled parcel by parcel⁷. Ask Planning and Zoning about the parcel and intended occupancy before buying or moving a unit.

1. Ask Planning and Zoning to confirm jurisdiction, district and the residential land-use approval to record with the deed¹. For a C-1 application, the published packet requires 14 site-plan copies, owners’ signatures, owners’ names and addresses within 300 feet, and agency signoffs including roads, health, fire and building review²⁰.

1. Confirm legal water: a private well needs an approved water right and State Engineer Start Card, and regulated wells require an appropriately licensed driller, subject to the limited owner option²¹.

1. If public sewer is unavailable, obtain Central Utah Public Health Department’s wastewater permit before the county can issue the building permit²².

1. Submit the building application, legal description and plat, zoning designation, plot plan, contractor information and two complete plan sets¹. Habitable structures must have a certified water source providing at least 40 psi and 1 acre-foot annually, plus continuous 100-amp electrical service¹.

1. Resolve required road-access approval, obtain the building permit and request inspections through final approval^11,22.

Before buying rural Millard County land, resolve water, wastewater, zoning and access. A private well requires State Engineer approval, while only 15.3% of mapped soils avoid a “very limited” rating for conventional drain fields, making early septic evaluation useful^17,21. C-1 site plans must identify floodplains, wetlands, drainage ways and water bodies; we could not confirm a universal county floodplain-development permit requirement, so ask Planning and Zoning what applies²⁰.

A county road encroachment permit is conditional on the access work, rather than required for every driveway; the permit carries a minimum $1,000 bond that the Road Supervisor may increase, and requires notice to the Road Department before work starts²². A new state-highway connection requires a UDOT conditional access permit²³.

Do not assume a parcel can be split informally: county subdivision rules include specific exemptions, and the non-plat application requires a utility plan and proof of adequate water for new dwellings, with a $165 administrative fee plus $10 per new lot or parcel²⁴.