Teaching staff, designing conventional courses in higher education, must make decisions about selecting content and activities to engage students in learning. When the Internet is chosen as the principal delivery vehicle it presents particular challenges for the design of active learning. Further challenges are added when working with a complex, multidisciplinary subject, with no unique solutions for the learner. This paper examines strategies employed in designing case study material to encourage active learning in sustainable development. Significant elements for successful practice are identified in the application of key learning design principles to meet the challenge of Web design for active and constructive learning. Principles of variety, action, application, interaction, feedback, scaffolding and evaluation are offered as a framework and set of benchmarks for teaching staff and learning technologists designing and evaluating Web-based learning initiatives. (Contains 2 figures.)