The thermal exchanges between the buildings and its surroundings may be easily evaluated from balance equations. However, some parameters in the equations are prone to changesdue to decisions taken by the users at some time, and further decisions and even computations onthermal behaviour may be strongly affected by the users attitudes and actions. This can producewrong computation of energy consumption and savings, and then they have to be avoided. On theother hand, wrong actions of the users or misuses might produce uncomfortable conditions that aredifficult or expensive to handle.