The increasing number of highly insulated and air tight buildings leads to the concern of indoor environment overheating and related comfort and health issues. This can already happen in a temperate climate as found in the Netherlands. This work studies the ventilative cooling process as a possibility to avoid overheated dwellings. A monitored dutch passive house was modelled in Trnsys and the impact of increasing air flow rates on indoor temperatures was simulated. The most overheated zone was chosen to be analysed. The ventilation rates were set in accordance with the ventilation system available in the house. Three possible ventilation rates were simulated and the results obtained for indoor temperatures were compared with measured data. The occupancy was estimated in accordance with registred CO2 levels and the other heat gains were calibrated based on indoor temperature during winter time. Results indicate that indoor temperatures can be considerably lowered by making use of constant outdoor flow rates during the warm season. However, alternative solutions such as shading devices and passive night cooling might be considered during very warm days, when outdoor temperatures rise above thirty degrees Celsius.