This paper explores the potential for using approaches and methods from anthropology to address inequalities and work with marginalised, voiceless groups to engage actively in decisions that affect them. We test and illustrate participatory action research (PAR) methods from anthropology that seek to understand tacit/implicit knowledge and values that may only be revealed through the study of day-to-day practices, behaviours and discourse over longer timescales. This is done through a case study of a planned development in Malta that included 170 interviews supported by situated listening and observation, observational visits over a period of time to the site and surrounding areas and public/stakeholder formal/informal meetings and workshops. Ethnographic methods helped build trust during the planning process, creating a communicative bridge for knowledge sharing. This qualitative research provided new insights based on tacit and implicit knowledge and values, highlighting specific subtleties, critical awareness, empathy and observational capacity, which are essential ingredients in socially just PAR. This included new insights into the way participation was shaped by broader socio-political contexts. By eliciting, analysing and integrating 'knowledges' in this way, action researchers can contribute to more socially equitable opportunities to participate and share power in knowledge creation.