Accessory Dwelling Unit (ADU) Permit in Sheridan, Wyoming

Sheridan requires an accessory dwelling unit (adu) permit for: Confirmed absence: Sheridan City Code Appendix A (Zoning) Chapter 2 (Definitions) defines only "accessory building" and "accessory use" — general incidental structures, not dwelling units; no "accessory dwelling unit," "ADU," "carriage house," or "secondary dwelling" term is defined anywhere in the zoning code; R-1 Residence District (Ch. 5) permits only one-family dwellings plus incidental accessory buildings/uses — no second dwelling unit permitted; R-2, R-3, and R-4 Residence Districts (Ch. 6-8) permit two-family/multi-family dwellings as principal uses (not as an accessory unit to a single-family home) plus incidental accessory buildings/uses — none of the four residential district chapters contain an ADU-specific process; Absent a dedicated ADU category, a legally accessory second dwelling would need to fit within the applicable district's permitted-use table (e.g., a duplex/two-family use in R-2+) and would be processed as a Detailed Building Permit (plan review) under the City's amended 2024 IRC/IBC; Contractor must hold a current City of Sheridan contractor license. If your project isn't listed, confirm with City of Sheridan Building Department at (307) 674-5941 before starting work.

In Sheridan, the published Residential New/Add/Alter — up to $100,000 valuation (general formula, likely applicable) is: Valuation x 0.03 x 0.8. 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 Sheridan typically runs 5–20 business days. This is an estimate, not a published figure — confirm current review times with City of Sheridan Building Department at (307) 674-5941.

You'll need: Building Permit Application (OpenGov Permit & Licensing Portal). See the required-documents checklist on this page for details on each.

Sheridan requires 4 inspection(s) for an accessory dwelling unit (adu) permit, in order: Foundation / Footings, Framing, MEP Rough-In, Final. Schedule each through City of Sheridan Building Department ((307) 674-5941).

Apply through City of Sheridan Building Department at 55 Grinnell Plaza, Sheridan, WY 82801. Phone: (307) 674-5941, email: Contact the Building Division via (307) 674-5941. Office hours: Mon–Fri 7:00 a.m.–4:00 p.m.. Official information: https://www.sheridanwy.gov/government/building.

Sheridan, Wyoming has adopted: 2024 International Residential Code (IRC) — as amended by City of Sheridan Ordinance No. 2290 (adopted Jan. 20, 2025); cited as the "Residential Code for One- and Two-Family Dwellings of the City of Sheridan"; 2024 International Building Code (IBC) — as amended by Ordinance No. 2290; cited as the "Building Code of the City of Sheridan"; 2024 International Mechanical Code (IMC) — as amended by Ordinance No. 2290; cited as the "Mechanical Code of the City of Sheridan"; 2024 International Plumbing Code (IPC) — as amended by Ordinance No. 2290; cited as the "Plumbing Code of the City of Sheridan"; 2023 National Electrical Code (NEC), as adopted/published by the NFPA — adopted as a City technical code by Ordinance No. 2290, amending NEC Section 230.70(A)(1) (exterior service disconnect location); 2024 International Fire Code (IFC) — as amended by Ordinance No. 2290, including Appendix Divisions D, E, F, G and I; cited as the "Fire Code of the City of Sheridan"; 2024 International Existing Building Code (IEBC) — as amended by Ordinance No. 2290; cited as the "Existing Building Code of the City of Sheridan"; 2024 International Swimming Pool and Spa Code (ISPSC) — as amended by Ordinance No. 2290; cited as the "Swimming Pool and Spa Code of the City of Sheridan"; 2024 International Fuel Gas Code (IFGC) — as amended by Ordinance No. 2290; cited as the "Fuel Gas Code of the City of Sheridan"; 2021 International Property Maintenance Code (IPMC), including Appendix A — as amended by Ordinance No. 2290; cited as the "Property Maintenance Code of the City of Sheridan"; 1997 Uniform Code for the Abatement of Dangerous Buildings (UCADB), as adopted/published by the International Conference of Building Officials — adopted by Ordinance No. 2290. Local amendments apply — see the Sheridan overview page for the full list.

No. The City of Sheridan's zoning code (City Code Appendix A) has no accessory-dwelling-unit definition or standard in its Definitions chapter or in any of the four residential district chapters (R-1 through R-4) — confirmed by direct review of those chapters. A second dwelling unit is only possible where the lot's zoning district already permits two-family/multi-family use (R-2 and above); it would be processed as a standard Detailed Building Permit under the 2024 IRC/IBC.