Knowledge workers solve complex problems. Their work seems not to be routinisable because of the unique results and constellation of actors involved. For distributed collaboration knowledge workers need many different tools, which leads to knowledge dispersed over different locations, artifacts, and systems. Contextbased adaptation can be used to support teams by shared workspace environments best meeting their needs. We propose an ontology representing context in a shared workspace environment, and a conceptual architecture for context sensing, reasoning, and adaptation. We report on first experiences demonstrating the applicability of our approach and give an outlook on directions of future work.