The paper deals with a problem that has been crucial in teaching and practising architectural design since the XVIII century, when the separation between the Academies and the Polytechnics denied the integration between art and science in architectural design. The question becomes more crucial today with the demands arising from the energy saving, environmental awareness and sustainability achievements. An analysis is proposed for focusing the reasons of such a separation and some interventions are suggested in order to improve the efficiency of a design process that composes architectures by means of architectures.