High level, abstract engineering thinking and design is a subject that is hardly addressed in current curricula for secondary education. This is contradictory to the increasing need for more in depth STEM education in secondary schools dictated by the evolution of our society towards an ever more STEM based information society. In this paper an approach is presented to introduce 16 year old Belgian pupils to some of the most important, basic concepts of control theory. Control theory is here exemplary for more general engineering science. The problem used to introduce control theory is that of heating system design in houses.