Mixed construction buildings are buildings where main load-bearing structure (load-bearing walls, columns binders, frames) are constructed of non-combustible materials (in particular: hollow brick, brick, stone, marble, concrete, reinforced concrete, steel) and the roofing is made of non-combustible materials (in particular: ceramic tiles, cement tiles, sheet metal, eternit). In mixed construction buildings, wooden constructions are acceptable only if one of the elements: the main load-bearing structure or the roofing is made of combustible materials.