Learning tasks in virtual worlds have produced evidence of their educational validity but implementations, however, do not always make full use of the educational possibilities - namely the potential for students to learn through design and construction of artefacts within the virtual environment and apply their learning to real world contexts. This paper outlines a design-based research project that is implementing and evaluating a virtual world that focuses on student design and construction of in-world artefacts and then transferring their ideas into real-world tasks. The discussion covers theoretical considerations, the challenges of construction and the progression of in-world activities that meet these challenges.