The push to design environmentally conscious and sustainable buildings has surged over the past twenty year, thus leading to the development of new methods for harnessing the natural elements of the earth. In recent years the international firm of Kohn, Pederson and Fox has been a champion of the sustainability movement. In fact many of the newer passive ventilation strategies under development can be seen in Kohn, Pedersen Fox International (KPFI) current commission for the World Trade Center (WTC) currently under construction in Amsterdam, Netherlands. This multi-million square foot complex has been designed to service the growing needs of Europe's free market economy and the fledgling European Union (EU). The complex is a series of five towers with connecting multi-storied atriums in the interstitial spaces. While the towers are actively heated and cooled using modern energy efficient systems the atrium areas are ventilated using an innovative passive system. This passive system relies on turbulence and negative pressure along the roof system to draw air through the space and positive pressure (due to wind driven forces) at the inlets located above the ground level doors to bring air into the atrium. The primary concept behind this strategy is that the difference between the positive and negative pressure zones will induce a convective current within the atrium space and there by create a continuous air-change system. The intent of this thesis is to analyze and report on the findings of the wind tunnel tests done on scale models of the complex and, propose alternative ideas to strengthen the current design. / Master of Science