Cheyenne’s current Unified Development Code (UDC) separates principal-dwelling form from the parcel’s zoning permission. Check both before estimating a project.
Check the lot’s principal dwelling
UDC section 5.7.3 allows one ADU per lot with a detached one-unit dwelling, where the district allows ADUs as a permitted, administrative, or conditional use. The code prohibits an ADU on lots with a multi-dwelling building, an attached dwelling, or a semi-attached dwelling. An ADU may be in the principal building or a permitted accessory building, but the district’s other lot and building standards continue to apply.
The use table and the parcel’s current district determine whether the route is permitted, administrative, conditional, or unavailable. A Citywide ADU rule does not mean the use is allowed in every Cheyenne district. Check the City’s zoning map and the current UDC table for the exact parcel.
Apply the size and notice standards
Under section 5.7.3, the ADU is limited to 40% of the principal dwelling, up to 1,200 square feet; the code’s floor-area calculation excludes a related garage, porch, or similar area. The size limit does not apply to a basement apartment, which may occupy the entire floor area of the existing basement. Other district standards still apply.
After the Director approves an ADU, the owner must record a Notice of ADU Regulations with the Laramie County real estate office. The notice needs a legal description of the property and must use a form approved by the Director. Confirm the current form, zone, use classification, and any later code amendment with Planning and Development.
This is a zoning screen, not an approval. For the broader process, see which zone allows a secondary dwelling and how project form affects eligibility.