With software services becoming a strategic capability for the software sector, service engineering needs to address integration problems based on support that helps services to collaborate and coordinate their activities. The increasing need to address dynamic and automated changes - caused by on-demand environments and changing requirements - shall be answered through a service coordination architecture based on event-based collaboration. The solution is based on a service coordination space architecture that acts as a passive infrastructure for event-based collaboration. We discuss the information architecture and the coordination principles of such a collaboration environment.