Abstract Behavior change towards sustainable lifestyles such as adoption of renewable energy technologies is a significant element in the fight against anthropogenic climate change. Increasingly, private households can be observed to take up different renewable energy technologies; however, the introduction of these technologies is not accompanied by a broader adoption of pro-environmental behaviors, as recent studies have shown. At the same time, group settings and social capital seem to promote the uptake of wide-ranging sustainability measures. Six case studies were conducted among different sustainable community projects in Germany to shed light on why and how broad sustainability transformation in such settings comes about. Findings suggest that successful implementation of wide-ranging sustainable measures and changes in behaviors in community settings result from motivations that originate from an interplay of social needs, social capital, social norms, and environmental concern. Strong environmental attitudes, not among all, but a critical mass of members and key individuals are necessary. The desire for community and other motives, along with social influence and social norms push individuals with low environmental concern to participate in sustainable endeavors.