The developing world has built structures on an unprecedented scale to accommodate population growth and urbanization. The horizontal and vertical structuring of the building stock resulting from this "megatrend construction" strongly influences urban and rural poverty, sustainability, resilience, and quality of life. However, due to data constraints, little is known about how and why 3D building patterns vary globally and in the developing world in particular. This study uncovers novel facts on global 3D building patterns as a result of outward and upward preferences in construction and investigates their relationship to the development process. To this end, new high-resolution data on the area, height, and volume of the global building stock are combined with various analyses undertaken at different spatial domains. The results show that building stock per capita increases convexly with income, but income only explains two-thirds of the differences in international volume. Additionally, while building upward systematically drives international volume differences, low-rise buildings still dominate construction patterns. Urbanization tends to reduce space consumption per capita as urban residents consume less volume than rural residents. Finally, the analyses of construction preferences may help to assess construction needs by forecasting volume requirements in developing Africa, Asia and Latin America.