In the field of house construction, prices are generally reported per square meter of built area. This means that you pay more for what you actually use. However, any property owner is directly interested in maximizing indoor space. Houses on metal structures have the best ratio between built and usable area. For example, for a 100 square meter metal house, the average useful area is about 10-12% less (~88 square meters), while in a traditional brick house the usable area is drastically penalized, with 20-25% (~75 square meters). The secret is that the metal wall profiles have a reduced thickness compared to bricks. Thus, the slightly smaller area occupied by the exterior walls and partition walls offers an advantage for houses with a metal frame.
It could be added that the quality of the execution is also an asset, because all the metal profiles are cut to exact dimensions in the factory. Their assembly is done without welding on site in just a few days with amazing precision.