This paper presents a research through design project to develop and interpret speculative smart home technologies for cohousing communities—Cohousing IoT. Fieldwork at multiple sites coupled to a constructive design research process led to three prototypes designed for cohousing communities, a Cohousing Radio, a Physical RSVP, and Participation Scales. These were brought back to the communities that inspired them as a form of evaluation, but also to generate new understandings of designing for cohousing. In discussing how they understand these prototypes, it offers an account of how research though design generates knowledge that is specific to the conditions and issues that matter to those communities. This contributes to design research more broadly in two ways. First, it demonstrates how contemporary ideas of smart home technology are or could be made relevant to broader ways of living in the future. Second, it provides an example of how a design research process can serve to uncover community values, issues, and goals.