An important tool for improving building energy efficiency and evaluating the consequences of various measures is computational building energy simulation. However, a major source of incorrect simulation results in buildings with natural ventilation is the misjudgement of the effect of wind pressure on the air exchange rate due to uncertainties in wind pressure coefficients. The simulation software commonly suggests default wind pressure coefficients for simple (cuboid) building shapes, while effects on the wind pressure of e.g. a pitched roof or attached wing building(s) are not considered. The present study investigates such effects in a building aerodynamic wind tunnel with a 64-channel pressure transmitter and setups with generic, stepwise-altered building geometries. The study provides a quantification of the impact on the pressure coefficients on e.g. a building façade by the presence of adjoining building structures.