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

At a glance

Building permit

Required for residential construction in unincorporated Millard County¹

Zoning

County zoning applies to unincorporated land²

Septic

Central Utah Public Health Department permit required before construction⁵

RV living

Campgrounds are conditional uses in some districts and prohibited in others; private-parcel occupancy is not confirmed⁶

Tiny home

Depends on local land-use classification and county approval⁷⁸

Owner-builder

A limited contractor-license exemption is available, but permits and codes still apply⁹

Private well

A valid water right and State Engineer permission are required before drilling¹⁰

Who to call

Contact details are copied from each office’s official page and were checked against it on October 11, 2026.

Do you need a building permit in Millard County, Utah?

Residential construction in unincorporated Millard County requires a building permit, and the county enforces adopted construction codes.¹¹¹ Regulated alterations, repairs, moves, demolition, occupancy changes, and gas, mechanical or plumbing installations also require approval before work begins.¹² The county building checklist says every residential dwelling in unincorporated Millard County requires a conditional-use permit recorded with the deed.¹³

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 placement.¹⁴ Plumbing, electrical and mechanical permits may still be required; acreage and location restrictions also apply.¹⁵ 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 testing.¹⁴

Inside Town of Lynndyl, the town handles building permits; onsite wastewater permits remain with Central Utah Public Health Department.¹⁶⁴

Who handles Millard County building permits?

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.³¹⁷ The permit holder or contractor must request required inspections, and a certificate of occupancy follows approved inspections.¹⁷ 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 letter.¹⁸

Planning and Zoning handles land-use applications.¹⁹ 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 change.²⁰²¹ Ask Planning and Zoning which residential approval applies, because the building checklist calls for a recorded conditional-use permit.¹³

Does Millard County have zoning?

Millard County zoning governs unincorporated land, outside municipal boundaries.²²² Town of Lynndyl administers its own zoning inside town limits; onsite wastewater approval remains with Central Utah Public Health Department.²³⁴ Uses on unincorporated land may be permitted, conditional or prohibited by district, and an unlisted use is prohibited.²

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 parcel.⁶ 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 districts.²⁴ 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 four.²⁵ In the AI, HC, LI and HI districts, lot size and yards are set case by case through site-plan approval.²⁶²⁷

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 compliance.²⁸ We could not confirm site-built minimum size, lot coverage or height limits; ask Planning and Zoning.¹⁹

How do septic permits work in Millard County?

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.⁴⁵ The application package calls for an application, soil classification, site plan, system design, and—when applicable—an operation and maintenance plan or contract.⁵

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 fixed.²⁹ Public-sewer connection is required when available and practicable; otherwise an adequate onsite or otherwise accepted wastewater system is required.³⁰ 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.

Can you live in an RV or tiny home in Millard County?

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 districts.⁶ The available county rule does not state a maximum stay for an authorized campground.³¹ Gunnison Bend Park is a separate case: overnight camping and parking are prohibited within the park.³²

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 home.⁷ 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 parcel.⁸ Ask Planning and Zoning about the parcel and intended occupancy before buying or moving a unit.

What are the steps to build a home in Millard County?

1. Ask Planning and Zoning to confirm jurisdiction, district and the residential land-use approval to record with the deed.¹³ 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 review.³³

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 option.³⁴

1. If public sewer is unavailable, obtain Central Utah Public Health Department’s wastewater permit before the county can issue the building permit.³⁵

1. Submit the building application, legal description and plat, zoning designation, plot plan, contractor information and two complete plan sets.¹³ Habitable structures must have a certified water source providing at least 40 psi and 1 acre-foot annually, plus continuous 100-amp electrical service.¹³

1. Resolve required road-access approval, obtain the building permit and request inspections through final approval.³⁶¹⁷

What should you check before buying land in Millard County?

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.³⁴²⁹ 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 applies.³⁷

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 starts.³⁶ A new state-highway connection requires a UDOT conditional access permit.³⁸

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 parcel.³⁹

Watch-outs

• An owner-builder exemption concerns contractor licensing; it does not cancel Millard County building permits, inspections, or code requirements.⁹
• Do not assume an agricultural building is exempt if it will be occupied or contain bathroom facilities; ask Building Inspection to confirm eligibility before construction.¹⁵
• Private-parcel RV occupancy, site-built minimum dwelling size, lot coverage and building height remain unconfirmed; ask Millard County Planning and Zoning about the exact parcel and use.¹⁹

Sources

1. Building Inspection – Millard County, quoted and re-checked
2. Title 10, Chapter 16 — Establishment of Zoning Districts, quoted and re-checked
3. Millard County Building Inspection Department (millardcounty.gov)
4. Onsite Wastewater Permit Instructions, quoted and re-checked
5. Onsite Wastewater Permit Instructions, quoted and re-checked
6. Millard County Code § 10-25-1, Appendix A: Table of Uses, quoted and re-checked
7. OPRO Accessory Dwellings (ADU's) and other dwelling types (Utah statewide rule), quoted and re-checked
8. Millard County Planning Commission Minutes, December 3, 2025, quoted and re-checked
9. Utah Code Title 58, Chapter 55 – State Construction Trades Licensing Act, quoted and re-checked
10. Water Well Drilling, quoted and re-checked
11. Building Inspection – Millard County, quoted and re-checked
12. Building Inspection – Millard County, quoted and re-checked
13. Building Inspection – Millard County, quoted and re-checked
14. Building Inspection – Millard County, quoted and re-checked
15. Building Inspection – Millard County, quoted and re-checked
16. Town of Lynndyl: Lynndyl Town Building Permit Application and Requirements (Millard County), quoted and re-checked
17. Inspection Notice, quoted and re-checked
18. Utah Code Title 15A – Third-party inspection firms, quoted and re-checked
19. Millard County Planning and Zoning (millardcounty.gov)
20. Millard County Land Use Fee Schedule, quoted and re-checked
21. Millard County Land Use Fee Schedule, quoted and re-checked
22. Planning and Zoning – Millard County, quoted and re-checked
23. Town of Lynndyl: Lynndyl Town Building Permit Application and Requirements (Millard County), quoted and re-checked
24. Millard County Code § 10-25-2, Appendix B-1, Development Standards, quoted and re-checked
25. Millard County Code § 10-25-2, Appendix B-1, Development Standards, quoted and re-checked
26. Millard County Code § 10-25-2, Appendix B-1, Development Standards, quoted and re-checked
27. Millard County Code § 10-25-2, Appendix B-1, Development Standards, quoted and re-checked
28. 10-25-1: Appendix A, Table of Uses and Accompanying Use Definitions, quoted and re-checked
29. Share of soils USDA rates "not limited" for a conventional septic drain field (SSURGO). A strict rating: the median county is about 6% and a tenth of counties are 0%, so a low figure means most lots need a site evaluation or an engineered system, not that septic is impossible. Cite it only with that caveat: Bolthole Index county data
30. DAR File No. 37575, Rule R317-4, Onsite Wastewater Systems (Utah statewide rule), quoted and re-checked
31. Millard County Code § 10-25-1, Appendix A: Table of Uses, quoted and re-checked
32. Millard County Code § 8-1-5, Gunnison Bend Park Rules and Regulations, quoted and re-checked
33. C-1 Conditional Use Permit Application, quoted and re-checked
34. Water Well Drilling Information, quoted and re-checked
35. Building Inspection – Millard County, quoted and re-checked
36. Building Permit Requirements, quoted and re-checked
37. C-1 Conditional Use Permit Application, quoted and re-checked
38. Conditional Access Permit (Utah statewide rule), quoted and re-checked
39. Millard County Non Plat Subdivision Application, quoted and re-checked

Written October 11, 2026 from the rules quoted below, each taken from an official source and re-checked by an independent reviewer. This is research, not legal advice: rules change, so confirm with the office before you buy or build.