This article explores legal knowledges and surveillance in residential condominiums, a form of property ownership and collective governing arrangement that is proliferating globally. Drawing from extensive empirical qualitative study of this realm in Toronto, Canada and New York, USA, including interviews with condo board members, owners and industry representatives, we map various legal knowledges and forms of surveillance and how these relate to condo governance and condo life. We demonstrate how surveillance is enabled by various legal knowledges flowing into the condo world, including those stemming from an evolving condo statute in the form of ‘counter-law’, but also from civil law, municipal law and criminal law. We show these legal knowledges have spawned video surveillance, key fobs, human surveillance, reserve fund studies, financial audits and safety inspections that together form a governing assemblage of private actors. This surveillance is largely focused on board and owners’ practices in relation to financial viability and property value, which has accompanied the condo becoming foremost an investment rather than a residential community. Much relevant legal knowledge and surveillance is increasingly commodified rather than developed or provided by the community, thus underscoring that the condo is an ever expanding conduit for the flow of such commodities. The article concludes with a discussion of several implications of this analysis, including the notion that the condo world may be experiencing a spiral of more and more law and surveillance.