Based on an extensive literature review on passive building designs for tropical climates, seven energy-efficient building design principles for tropical climate areas were deduced. These are: 1. To orientate a building design in such a direction that it protects from excessive solar radiation; 2. To accommodate for indoor natural ventilation; 3. That it makes maximal use of indirect instead of direct natural light; 4, That it reduces the amount of heat transmission through the roof as much as possible by natural ventilation between roof and ceiling and by lowering the roof surface temperature; 5. By preventing the use of high thermal mass materials; 6. By reducing through the exterior walls as much as possible heat transmission by e.g., preventing direct sunlight on the external walls and applying reflective paints on the external walls and; 7. By creating outdoor and transition spaces such as balconies, terraces atriums and corridors. The insights from the literature review were used as input to conduct a field study to evaluate the practice of applying passive building design principles. To this end, for 626 buildings on the Caribbean island Curaçao, it was investigated to what extent the recommended passive design principles for tropical climates were actually applied. Based on the results of the field study, several recommendations are made to improve the practice of applying passive building principles.