While researchers broadly agree on what enables and constrains teacher professional learning, reconfigured large teaching spaces potentially create new processes and content for this learning. In this paper we draw on six years of study of teacher adaptation to these settings in 10 schools in regional Australia to identify the nature of, and key influences on, this learning. Our analyses are based on a theoretical framing of relational agency illustrated in two case studies of sustained teacher interventions. We found that teachers' professional learning (TPL) in these contexts entailed learning new roles, developing new practices, and understanding the warrants for these practices. TPL was enabled by (a) extensive improvisation and intensive collaboration; (b) opportunities for teachers to observe teacher practices in other schools, and customise them for their own schools; and (c) extended partnerships between teachers and researchers.