Nowadays buildings are rarely able to guarantee adequate conditions of comfort both in winter and in summer without a high consumption of energy. We have to adapt ourselves to the actual environmental and economic conditions: we have to design sustainable buildings that can be dynamic entities. The fusion between traditional technologies (ventilated facade, Trombe wall) and innovative materials (electrochromics, phase-change materials) could allow, today, to realize buildings able to change their behaviour in accordance with external conditions and to produce the energy needed for their operation. This paper compares the behaviour in energy consumption for heating and cooling of three models located in Mediterranean climates. A building modelled in three different versions has been studied: with a traditional wall, with a Trombe wall with conventional glazing, and with a Trombe wall with electrochromic glazing. Calculations reveal that the third hypothesis (electrochromic wall) is the best option and it allows an energy saving of 17.6% (compared to the first option), and of 29.5% (compared to the second one). Studies and tests are necessary to better understand behaviour, performance, effectiveness of this solution. Without doubt it appears like a useful way to pursue energy saving and create sustainable buildings and comfortable houses. (C) 2013 Elsevier B.V. All rights reserved.