Using Facebook Groups to connect otherwise anonymous people that live in a single urban development is a relatively new phenomenon. Within residential developments, there are a number of common comfort, management, and performance issues experienced by many isolated inhabitants that are identified through building performance evaluation studies. Facebook is a ubiquitous social network tool and powerful communication platform, particularly popular among young adults. This article explores the use of closed Facebook Groups in relation to collective learning about home use in two residential communities in the United Kingdom. Data were collected through longitudinal digital and physical visits to case study residential developments and to the Facebook Group sites. Group development, dynamics, and the quality of knowledge sharing is evaluated. Findings are presented in relation to home use learning, as it proved to be a vital theme of each Group’s activity. We propose that weak-tie urban communities can develop collective efficacy through communicating on a Facebook Group that enables quality learning based on reciprocal sharing of experiences and knowledge by its members. This helps tackle comfort issues experienced, lower the cost of living, and share bespoke, context-specific home use best practice. Strong engagement and leadership of group administrators limited to early stages of the Groups’ formation followed by high rate of activity by the majority of members was key. There was a clear overlap observed between social media narrative and the physical experiences of daily life, which helps support residents. The analysis suggests the positive effect of the learning environment created bottom-up would not be easily transferable to professional applications.