This paper discusses issues in the development of collaborative efforts among stakeholders in a community housing and support system dedicated to people with serious mental illness. Whereas community development efforts directed at localities are more common, the increasing recognition of the system-level barriers facing marginalized groups requires community development efforts that are relevant to communities of stakeholders in service systems. The paper draws on work conducted by the authors to understand, to evaluate, and to support the development of a system of housing dedicated to people with serious mental illness in Ontario. Although these projects were not intended as community development, they have uncovered issues that are likely to arise in a community development effort in this context.