Differences in how we build: Material use and intensity in small multi-units’ buildings in Brazil, Canada, Greece, Nigeria and Switzerland

The growing global population is increasing the demand for housing at the same time as the ecological limits requires much more resource-efficiency. This study examines material use and intensity (MI) in small multi-unit buildings across five countries (Brazil, Canada, Greece, Nigeria, and Switzerland). Using detailed bottom-up material quantification the study compares 50 small multi-unit residential buildings - with 3 to 35 units - built between 2014 and 2024. Concrete use is dominant across countries, making up 75 % of the material mass, particularly in floors, slabs, and exterior walls. Security concerns are found to increase material use. Climate also has an impact on MI. Overall, building size and cultural preferences, including bedroom and bathroom sizes, drive material use. This research adds needed geographical diversity to our understanding of construction material use and insight on how building norms drive MI.