Accessory Dwelling Units

The City of Hailey recognizes that land use, population growth, and community character are interrelated, and that social well-being and diversity are tied to the availability of an array of housing types and sizes available for sale and for rent at various price points. Accessory dwelling units, when thoughtfully designed, can simultaneously complement the fabric of existing neighborhoods, increase the supply of available housing, and sustainably accommodate population growth.


In Hailey's Municipal Code, Accessory Dwelling Units (ADU) are defined as:

A structure subordinate to the principal use on the same lot or premises having kitchen facilities and at least one bathroom, to be occupied as a residence, which is incidental to the use of the principal building.

Accessory dwelling units may be located within, or attached to, a principal building or may be located within a detached accessory building. Detached accessory dwelling units may comprise the entirety of the accessory building or may comprise part of the floor area of an accessory building with another permitted accessory use or uses comprising the remaining floor area. For example, an ADU may be located above a detached garage.

Section 17.08D.010 of Hailey's Municipal Code outlines the following stipulations for ADUs:
  • Only one (1) accessory dwelling unit is permitted on a lot.
  • In residential zones, ADUs are only permitted in conjunction with primary residences.
  • In the Townsite Overlay, Transitional, Service Commercial Industrial, Business, Limited Business, and Neighborhood Business Zoning Districts, ADUs are permitted in conjunction with commercial and mixed-use buildings.
  • All ADUs require registration and a Compliance Certificate.
  • Where a lot contains both a primary dwelling unit and an accessory dwelling unit, only one (1) dwelling unit shall be utilized for short-term occupancy. At least one (1) of the dwelling units shall be owner-occupied or utilized as a long-term rental, with long-term occupancy being a period of thirty-one (31) days or more.
  • The floor area of an accessory dwelling unit (ADU) is limited to no more than sixty-six percent (66%) of the gross square footage of the principal building, or the maximum floor area permitted for an ADU based on the lot size or zone, whichever is less. See Section 17.08D.010 for additional size restrictions.
  • Accessory dwelling units may have a maximum of two (2) bedrooms.
  • All accessory dwelling units shall have a designated area to access the outdoors. Examples include a balcony, porch, deck, paver patio, or yard area delineate by fencing, landscaping, or similar treatment so as to provide for private enjoyment of the outdoors. This area shall be no less than fifty (50) square feet in size.

Read a 2022 Update on ADUs in Hailey!

Accessory Dwelling Unit