The paper summarizes the activites undertaken by AppliedSensor within the European Clear-up project with respect to new developments in volatile organic compound sensing for demand controlled ventilation. State-of-the-art is to use non-dispersive infrared sensor technology for indoor carbon dioxide detection. Carbon dioxide so far serves as indicator for bad indoor air quality and required ventilation rates. Indoor events coming along with complex mixtures of gaseous compounds, mainly volatile organic compounds, released by human bio-effluents, cooking odours, outdoor pollutants, cleaning supplies as well as building material and furniture emissions, play a pronounced role for human air quality perception and health, but cannot be dectected with carbon dioxide as indicator. Within the European Clear-up project, AppliedSensor worked on the development of metal oxide semiconductor based indoor air quality monitoring modules spezialized for demand controlled ventilation, closing the gap between pure CO2 and volatile organic compound only detection, their implementation in test facilities and enhancement for wireless application.