In looking to address the nation-wide affordable housing crisis, many advocates have turned – literally – to their own backyards. Accessory Dwelling Units (ADUs) can be a solution that provides additional units of housing in areas where single-family homes dominate. As smaller units of housing that can be built on the property of the main house, they can accommodate short- or long-term renters or additional family members, as well as supply a source of supplemental income to the homeowner. Invest Health Field Building city teams from Grand Rapids, Missoula, Napa, and Riverside – led by Lark Ferrell, Housing Manager for the City of Napa and Lisa Beczkiewicz, Health Promotion Supervisor for the Missoula City-County Health Department – collaborated with Kol Peterson, ADU expert and author of Backdoor Revolution: the Definitive Guide to ADU Development, to bring five days of virtual programming about ADUs to Invest Health city teams and other local stakeholders.