Air renovation inside buildings is crucial to have productive workers, since the lack of good indoor conditions affects human activity and promotes diseases (Fisk, 2000). This happens particularly in non-residential buildings where usually there is high occupation and thus big needs for fresh air. To achieve good indoor air quality (IAQ), actual ventilation solutions need a significant amount of energy, which is estimated to be about 10% of the total energy used in Europe (RESHYVENT, 2004). On the other hand, climate changes due to CO2 emissions and derived from mankind activities mean that energy use must be rationalized and used in efficient ways. Although some new energy friendly ventilation solutions were developed, they face hard barriers to achieve a considerable market entry and spread. This article aims to understand, behind a technical perspective, why this happens and also analyses what can be the potential energy savings when advanced ventilation techniques are employed over the European main climate zones. Results show that for European high cooling load climate, where night temperatures are too high, night cooling ventilation can achieve a minor or even an adverse effect. However in a colder climate this strategy together with high inertia construction gets considerable decreases on daily peak temperatures and cooling energy demand. On the cases where natural ventilation was used, energy savings reached more than 20% in energy delivered to the buildings.