This study focused on the efficient use of cross-ventilation in a densely populated area. Wind tunnel experiments were conducted to understand the relation between the building coverage ratio and the wind pressure coefficient. The experiments and calculations revealed the following information: (1) the overall Cp value of a flat roof residence approaches zero when the building coverage ratio increases; (2) a negative pressure is maintained near the ridge of a leeward roof; and (3) the efficient use of the negative pressure near the ridge on the leeward roof can improve the cross-ventilation rate in a densely populated area.
