Building Age-Friendly Communities Act This bill modifies an existing committee and makes other changes to incorporate age-friendly communities in federal programs and services for older adults. The bill defines age-friendly communities as those that (1) are taking steps to meet local needs for accessible housing, transportation, and public spaces, as well as for civic participation and social connectedness; and (2) have a plan to guide those efforts. Specifically, the bill renames the Interagency Coordinating Committee on Aging as the Interagency Coordinating Committee on Age-Friendly Communities and more specifically focuses the committee's work on promoting and developing these communities. The committee must also work with the Centers for Disease Control and Prevention and relevant federal agencies to develop recommendations for evidence-based prevention programs and home modifications to reduce and prevent falls among older adults. In addition, the Administration on Aging may provide technical assistance to state and local governments and others on age-friendly communities.