Low income, multi-ethnic communities in Main South/Piedmont neighborhoods of Worcester, Massachusetts are exposed to cumulative, chronic built-environment stressors, and have limited capacity to respond, magnifying their vulnerability to adverse health outcomes. "Neighborhood STRENGTH", our community-based participatory research (CBPR) project, comprised four partners: a youth center; an environmental non-profit; a community-based health center; and a university. Unlike most CBPR projects that are single topic-focused, our 'holistic', systems-based project targeted five priorities. The three research-focused/action-oriented components were: (1) participatory monitoring of indoor and outdoor pollution; (2) learning about health needs and concerns of residents through community-based listening sessions; (3) engaging in collaborative survey work, including a household vulnerability survey and an asthma prevalence survey for schoolchildren. The two action-focused/research-informed components were: (4) tackling persistent street trash and illegal dumping strategically; and (5) educating and empowering youth to promote environmental justice. We used a coupled CBPR-capacity building approach to design, vulnerability theory to frame, and mixed methods: quantitative environmental testing and qualitative surveys. Process and outcomes yielded important lessons: vulnerability theory helps frame issues holistically; having several topic-based projects yielded useful information, but was hard to manage and articulate to the public; access to, and engagement with, the target population was very difficult and would have benefited greatly from having representative residents who were paid at the partners' table. Engagement with residents and conflict burden varied highly across components. Notwithstanding, we built enabling capacity, strengthened our understanding of vulnerability, and are able to share valuable experiential knowledge.