This HIA, carried out by the Benton County Health Department, evaluated a series of policy-change scenarios to amend the existing county code for Accessory Dwelling Units (ADUs). ADUs are small, self-contained residential units that are built on the same lot as—and are secondary to—an existing single-family home. The HIA was intended to inform a community debate around the issue. Some of the health influences examined in the HIA include access to good and services, social cohesion, healthy housing, transportation and mobility. The HIA recommended that an amendment be made to the existing ADU county code to allow dependent ADUs. However, it suggested a series of mitigation strategies that: 1) required the ADU resident be the home owner, a relative or caregiver; 2) did not allow the ADU to be used as a rental property; 3) capped the number of ADU permits allowed each year; and 4) required a regular review of the policy to minimize the occurrence of any unintended consequences.