Many brownfield development projects and many redevelopment projects aimed at improving older urban spaces list sustainable development as a stated goal. It is a key question, however, whether the benefits of these redevelopment projects are equitably shared with the original members of the community, and in the case of brownfields with residents of adjacent neighbours, or are there differential benefits that accrue to new higher-income residents at the expense of current residents and retailers, and at the expense of existing community diversity? A case study of a brownfield development in Victoria, Canada, confirms concerns in the literature about income diversity in brownfield developments; a second case study of a Toronto neighbourhood suggests that there is no guarantee that local sustainable development projects within existing neighbourhoods will encourage or even maintain existing social diversity and equity. A similar trend is demonstrated in a series of infill projects that had profound ramifications on adjacent communities and indeed contributed to greater unsustainability in the Downtown Eastside of Vancouver, British Columbia. It is concluded that the relationship between sustainable development and gentrification is more complex than has been previously suggested.