Utah Code § 17-80-301: Moderate income housing.

(1) A county may only require the development of a certain number of moderate income housing units as a condition of approval of a land use application if:

(a) the county and the applicant enter into a written agreement regarding the number of moderate income housing units;

(b) the county provides incentives for an applicant who agrees to include moderate income housing units in a development; or

(c) the county offers or approves, and an applicant accepts, an incentive described in Section 17-80-401 or 17-80-402.

(2) If an applicant does not agree to participate in the development of moderate income housing units under Subsection (1)(a) or (b), a county may not take into consideration the applicant's decision in the county's determination of whether to approve or deny a land use application.

(3) Notwithstanding Subsections (1) and (2), a county of the third class, which has a ski resort located within the unincorporated area of the county, may require the development of a certain number of moderate income housing units as a condition of approval of a land use application if the requirement is in accordance with an ordinance enacted by the county before January 1, 2022.