Recent advances in Web 3D technology have opened a wide area for Collaborative Virtual Environments (CVE). While CVE are often viewed in a concurrency context, they need to provide a satisfying experience in terms of consistency, latency and recovery. Because (i) Event-Driven architectures (EDA) are well-suited for distributed application and (ii) traditional communication architecture (client-server) can be limited in such situations, this paper presents a loosely-coupled approach combining event sourcing with a hybrid communication architecture. This model aims to ensure a strong versioning system and resource availability for collaborative 3D object manipulation in a web browser. To evaluate acceptance of our system, we conducted a user study on groups of users working simultaneously on 3D cooperative assembly tasks. The results detail the users’ involvement evolution, qualitative appreciations of the system’s usability and the collaborative features.