Accessory Dwelling Unit (ADU) Permit in Riverton, Wyoming

Riverton requires an accessory dwelling unit (adu) permit for: No ADU-specific zoning category exists; R-1, R-2A, and R-4 districts have no provision for a secondary dwelling unit on a single-family lot; R-2 Residential District (RMC § 17.32.010–.040) permits a duplex (two full living units) as a permitted use: minimum lot area 5,000 sq ft, maximum 2 living units per lot, each unit minimum 425 sq ft floor area, max 40% lot coverage by main + accessory buildings, paved parking/driveway required for multi-family; A true second unit in Riverton must be built under the standard residential building permit process for the applicable zoning district (R-2 for a duplex) — there is no owner-occupancy requirement, no size-ratio-to-primary-structure limit, and no distinct 'ADU' fee; Property must first be confirmed as zoned R-2 (or petitioned for rezone) — R-1 does not allow a second dwelling unit. If your project isn't listed, confirm with City of Riverton Community Development Department — Building Division at (307) 856-2999 before starting work.

In Riverton, the published New Residential Construction (duplex, per RMC R-2 district) — same as residential-building-permit is: $0.42 per square foot of building area (includes building and all building systems). These are the jurisdiction's own published figures — see the fee schedule table and source citations on this page.

Plan review for an accessory dwelling unit (adu) permit in Riverton typically runs 1–30 business days. This is an estimate, not a published figure — confirm current review times with City of Riverton Community Development Department — Building Division at (307) 856-2999.

You'll need: Application for Building Permit; Zoning Verification. See the required-documents checklist on this page for details on each.

Riverton requires 1 inspection(s) for an accessory dwelling unit (adu) permit, in order: Standard new-construction inspection sequence. Schedule each through City of Riverton Community Development Department — Building Division ((307) 856-2999).

Apply through City of Riverton Community Development Department — Building Division at 816 N. Federal Blvd., Riverton, WY 82501. Phone: (307) 856-2999, email: kpetersen@rivertonwy.gov. Office hours: Mon–Fri (contact department for current hours); building permitting/inspection line (307) 857-7708. Official information: https://www.rivertonwy.gov/departments/community_dev/building_permits___inspections/index.php.

Riverton's Zoning Code (Title 17) has no ADU ordinance or permit category. The only way to add a second dwelling unit on one lot is if the property is zoned R-2, which permits a duplex (maximum two living units, each at least 425 sq ft) as a standard permitted use — built and permitted like any other new residential construction, not as a distinct 'ADU.' R-1-zoned single-family lots do not allow a second unit at all.

No. Because there is no ADU category, a second unit is charged the standard new-residential-construction fee ($0.42 per square foot of building area under Resolution No. 1355), the same as any other new dwelling.