Guidelines for health-based ventilation in Europe are proposed. They follow the premise of controlling exposures to indoor air pollutants of both indoor and outdoor origin. Exposures are controlled through a two-step sequential approach, in which source control is the primary strategy, while ventilation is the secondary strategy once all options for source control have been fully implemented. World Health Organization (WHO) air quality (AQ) guidelines are used to set the exposure limits. A decision diagram is created for guidance through the process of source control and to aid in choosing the ventilation rate for a specific building. The health-based ventilation guidelines do not define a specific system to provide ventilation. They advise on design, operation, and maintenance of such systems, so that the air supplied always complies with WHO AQ guidelines. Implementation of the health-based ventilation guidelines, it is estimated, would halve the loss of healthy life years in Europe from indoor exposure to poor air quality, from 2 mil. to 1.1 mil., without significant impact on energy. Actions supporting implementation of the guidelines are expected to result in advancement in knowledge and technological innovation; they will secure the basic human rights to live in clean air.