Basic material for the instruction of occupants of homes. How, when and where to use your windows.

Airtightness measurements were carried out in ten typical Dutch dwelling complexes. In each complex four homes were measured. The IMG calculation model was used to calculate expected ventilation for these dwellings. Results of a survey of 1500 occupants on use of ventilation are given. The ventilating behaviour in 610 homes was studied in greater detail. 210 of these had some form of mechanical ventilation. Ventilation requirements are given for individual rooms. To provide efficient ventilation, the system must be welldesigned, of adequate dimensions, easily controllable and adjustable, within reach of the inhabitant and easy to handle. It should cause no draught or noise nuisance. Occupant education is also important.