Building permits, zoning and septic rules in Park County, Wyoming

Unincorporated Park County requires a Building/Zoning Permit to locate, erect, construct, or enlarge a building or structure, reconstruct within a designated floodplain, change use, or increase sewage design flow through an occupancy change¹. The administrative permit covers uses allowed by right; site-plan review may also apply¹. Park County has not adopted a general building code and does not require a county Certificate of Occupancy or Completion, although separate state fire and electrical review may apply². Wyoming owners may act as general contractor on their primary residence, subject to local approvals and electrical licensing requirements⁶. Unlike most counties around it in Wyoming, Park County requires a county building permit¹. Inside Powell, the city issues building permits; the county septic authority described here covers unincorporated land^4,7.

Park County Planning and Zoning issues Building/Zoning Permits and administers small-wastewater permits for unincorporated land^1,4. Visit 1002 Sheridan Ave., Suite 109, Cody, WY 82414; call Cody at (307) 527-8540 or Powell at (307) 754-8540, or email planning@parkcounty-wy.gov¹. Park County publishes applications for Building/Zoning, floodplain development, wastewater systems, site-plan review, special uses, variances, zoning amendments, and subdivisions⁸. The county publishes its planning and zoning fee schedule, payment methods, and processor charges⁸. We could not confirm a general county building-inspection requirement; ask Planning and Zoning which inspections and separate state reviews the project needs.

Park County's Development Standards and Regulations govern land uses and structures throughout unincorporated Park County³. Inside Powell and Cody, each city's own zoning applies⁹; we could not confirm who issues building permits inside Cody; county wastewater authority described here is for unincorporated land^4,10. Standard minimum lot sizes range from one-half acre in R-H, C, I, and T to 40 acres in GR-40, subject to district rules and exceptions³. Buildings generally need 20 feet from the county road right-of-way edge and 5 feet from an alleyway, with exemptions for irrigation facilities, earthworks, fences, non-illuminated signs, and minor utility uses³. Where the road right-of-way is unknown, the rule permits measurement beyond a point 30 feet from the road center³. Highway-adjoining properties subject to site-plan approval have an additional setback of 20 feet per 5,000 square feet of floor area, potentially reduced for mitigating design³. Accessory housing is allowed by right with a Building/Zoning Permit when on the principal dwelling's parcel and smaller in living area³.

Park County Planning and Zoning exercises delegated Wyoming DEQ authority over small wastewater systems in unincorporated Park County; the county reviews plans, inspects, issues permits and enforces violations, and DEQ design rules still apply⁴. New, replacement, and repaired conventional septic-tank and leach-field systems below 2,000 gallons per day require a county Permit to Construct before work starts⁴. Published application fees are $250 for a new or replacement system and $125 for a modified or repaired system¹¹. Submit the design before installation, and do not backfill any component until the Small Wastewater Systems Administrator has inspected and the county has granted permission^4,8. Only 7.7% of county soils rate “not limited” for conventional drain fields; that does not mean septic is impossible, but a site evaluation and possibly an engineered system are needed¹². Outhouses, privies, greywater systems, and similar proposals require county and/or Wyoming DEQ review, and a wastewater permit is needed before building a small wastewater facility².

In unincorporated Park County, residential RV or camper use generally cannot exceed 90 days per calendar year unless the unit qualifies for a Building/Zoning Permit as principal or accessory housing or a construction home and has approved sewage disposal; commercial campgrounds are excepted³. Sunlight, Upper South Fork, and North Fork prohibit permanent RV living, defined as occupancy exceeding 90 days in any year; longer construction-home use needs a Building/Zoning Permit, a variance, and approved sewage disposal³. Manufactured/mobile homes must be on a foundation or blocked, skirted, and tied down within 60 days of placement³. In those planning areas, only off-frame modular factory-built homes are permitted, subject to an exception for replacing an existing factory-built home³. We could not confirm a separate tiny-home classification or minimum dwelling size; ask Planning and Zoning how the proposed design is classified before buying the unit.

1. Ask Park County Planning and Zoning to identify the parcel's district, minimum lot size, setbacks, and application requirements before fixing the site plan^3,8.

1. Obtain the Building/Zoning Permit before locating or constructing the structure; site-plan or state fire review may also apply^1,2.

1. For construction in a mapped Special Flood Hazard Area, obtain a floodplain development permit; applications go to a Board of County Commissioners public hearing, and residential structures must sit at least 2 feet above base flood elevation or 3 feet above the highest adjacent grade².

1. Obtain the septic Permit to Construct before installation and county inspection and permission before backfill⁴.

1. Receive the State Engineer's groundwater permit before drilling a well; the domestic filing fee is $50⁵.

1. Before dividing land, establish the applicable subdivision or exempt-division process with Planning and Zoning; simple, minor, major, and non-exempt large-acre subdivisions require subdivision permits, and exempt divisions still need a record of survey². Agricultural divisions require a Certificate of Filing and an agricultural-purpose covenant presented to the County Clerk for recording with the dividing instrument^3,13.

Federal land covers about 79.2% of Park County, making parcel boundaries relative to public land a useful purchase check¹². Park County's severe-drought history and 22.3 inches of annual precipitation make water rights and well yield worth investigating before committing to a well¹². Wells require a State Engineer's permit before drilling and licensed well-drilling and pump-installation contractors⁵. A driveway onto WYDOT right-of-way needs state approval through the local WYDOT Maintenance Foreman using Form M-3A¹⁴. We could not confirm county-road driveway requirements; ask Planning and Zoning who reviews access for the parcel. Typical home values are about $458,012, with an effective property tax rate around 0.6% and a median annual tax bill near $2,115¹².