The new proposal for ventilation requirements in the National Building Code of Finland is on public review. The structure of the proposal is different from the existing ventilation code. Minimum requirements for acceptable indoor climate will be given to a wider extent than before, eg new requirements for indoor air temperature and purity are proposed. Also the quality of outdoor air should be taken into account in design of ventilation. Health aspects are also considered, based on today's international knowledge of indoor air quality and human health.