Despite their recognised value, Lessons Learned (LL) in construction client organisations often remain fragmented and limited to documentation, with little effect on practice. These practices remain fragmented and lack methods for systematic evaluation and context-sensitive improvement. The study is structured around three interdependent domains – networks, coordinators, and systems – which provide the foundation for analysing LL as more than a documentation exercise. Guided by Structuration Theory, employed here to connect social and technical dimensions, the research draws on qualitative interviews with four Dutch infrastructure clients. The analysis leads to the development of a socio-technical framework that enables organisations to diagnose current practices and tailor strategies for improvement. By bridging formal procedures with informal dynamics, the framework helps transform LL into a living practice that enhances project outcomes and strengthens organisational learning.