As everybody knows, today the air quality of an indoor environment may have several effects on our health; the beginning of serious breathing pathologies and of some forms of cancer, are with no doubt due to the presence of polluting and extremely noxious agents in the places we most frequently use. That's the reason why it is very important that indoor rooms are correctly aired also in our homes where, due to several incidental factors, the healthiness of the environment is still guaranteed by the mere and discretionary operation of users of opening the windows. In considering the growing attention drawn to these problems and in agreement with the provisions of the 3rd essential requirement laid down in Common Directive 89/106, 'Hygiene, Health and the Environment', ICITE has undertaken to develop a research and experimentation study aimed at establishing a device for the controlled natural ventilation of residential environments. The main objectives have focused on the technical and performance-oriented characteristics of the devices that are already available on the Community markets and on the regulative aspects for what concerns air healthiness in domestic environments, while the final phase of the work, still in progress, will give new developping guidelines, both in regulative and productive terms. Surveys carried out on existing buildings pointed out a preference for one particular device, supplied with a self-adjusting ventilator which works according to the changing weather conditions, but able to control a certain kind of natural ventilation even with strong external winds and rain. Such a device was chosen mainly because of the declared peculiarity of mechanical factory control in any situation, since the greatest part of the market supply is oriented towards closing devices beyond fixed levels of internal pressure, thus restoring ·the tigthness conditions of the environment.