Purpose: This study aims to depict how a change laboratory (CL) promotes sustainable professional practice at the workplace to tackle unequal access to educational success. Design/methodology/approach: The empirical findings are from a CL focusing on school professionals' agency and a follow-up study one year after the CL. Findings: The study shows how the staff gained insight that professional agency is a collective and relational practice. Furthermore, the staff explored how to make a difference with viable means to create new workplace models for students' success despite experiencing a conundrum. Research limitations/implications: This study examined participants' perspectives in workplace change and provided support for further research examining how professionally and collectively designed models gain sustainability in schools. Practical implications: This study provides empirical data of how professional agency for change driven by collective visions can be accelerated with the interventionist method CL among school professionals. Social implications: This study emphasizes the value of professional collective learning at the workplace, driven by several professional groups in school, and the need to follow up to detect sustainable change. Originality/value: This study emphasizes the value of professional collective learning at the workplace, driven by several professional groups in school, and the need to follow up to detect sustainable change.