One of the major issues confronting users of solar energy-based systems is the relatively low efficiency of these systems when compared with fossil fuel-based systems. In this paper we take a fresh look at the generation of architecture of these systems based on the constructal theory. Three different systems are investigated: a shading system to control the incoming of solar radiation during the summer and the winter, a bundle of pipes to warm a room, and a distillation system integrated in a roof. The constructal principle invoked in this paper shows that geometrical form of systems can be deduced from a single principle and provides designers with tools for their conceptual design. (C) 2007 Elsevier B.V. All rights reserved.