Steel is heavier than building materials such as concrete, but its strength is much higher. For example, under the same load conditions, the weight of the steel roof truss is only 1/4-1/3 of the same span of reinforced concrete roof truss, and if the thin-walled steel roof truss is lighter, only 1/10. Therefore, steel structures can withstand greater loads and span larger spans than reinforced concrete structures.The energy-saving effect is good. The walls are made of lightweight, energy-saving and standardized C-shaped steel, square steel, and sandwich panels. They have good thermal insulation performance and good earthquake resistance.