In fact, there is no heavy steel in specifications and technical documents. In order to distinguish steel structures of light houses, it may be more appropriate to call general steel structures "ordinary steel". Due to the wide range of ordinary steel structures, which can include all kinds of steel structures, regardless of the load, and even many contents of light steel structures, the technical specification for steel structures of light buildings only stipulates some more specific contents according to its "light" characteristics, and the scope is limited to single-layer portal frames.

轻钢也是一个比较含糊的名词，一般可以有两种理解。一种是现行《钢结构设计规范》中“圆钢、小角钢的轻型钢结构”，是指用圆钢和小于L45＊4和L56＊36＊4的角钢制作的轻型钢结构，主要在钢材缺乏年代时用于不宜用钢筋混凝土结构制造的小型结构，现已基本上不大采用，所以这次钢结构设计规范修订中已基本上倾向往掉。另一种是《门式刚架轻型房屋钢结构技术规程》所规定的具有轻型屋盖和轻型外墙（也可以有条件地采用砌体外墙）的单层实腹门式刚架结构，这里的轻型主要是指围护是用轻质材料。既然前一种已经快取消，所以现在的轻钢含义主要是指后一种。

Light steel is also a vague term, which can be understood in two ways. One is the "light steel structure of round steel and small angle steel" in the current code for design of steel structures, which refers to the light steel structure made of round steel and angle steel smaller than L45 * 4 and L56 * 36 * 4. It is mainly used for small structures that are not suitable to be made of reinforced concrete structure in the era of lack of steel, which is basically not used now, Therefore, the revision of steel structure design code has basically tended to go away. The other is the single-layer solid web portal frame structure with light roof and light external wall (masonry external wall can also be used conditionally) specified in the technical code for steel structure of portal frame light house. The light here mainly refers to the light material used for enclosure. Since the former has been cancelled, the meaning of light steel now mainly refers to the latter.

轻钢结构是一种年轻而生命力的钢结构体系，已广泛应用于一般工农业、贸易、服务性建筑，如办公楼、别墅、仓库、运动场馆、娱乐、旅游建筑和低、多层住宅建筑等领域，还可用于旧房增层、改造、加固和建材缺乏地区、运输不便地区、工期紧、活动式可拆迁建筑等，倍受业主青睐，主要有以下特点：

Light steel structure is a young and vital steel structure system. It has been widely used in general industrial, agricultural, trade and service buildings, such as office buildings, villas, warehouses, sports venues, entertainment, tourism buildings and low and multi-storey residential buildings. It can also be used for storey addition, transformation, reinforcement of old houses, areas with lack of building materials, areas with inconvenient transportation, tight construction period Movable removable buildings are favored by the owners, mainly with the following characteristics:

）采用轻型薄壁型材，自重轻、强度高、占用面积小。

）High efficiency light-weight thin-wall profile is adopted, with light weight, high strength and small occupied area.

）构配件均为自动化、连续化、高精度生产，产品规格系列化、定型化、配套化。各部分尺寸精确。

）The components and parts are produced automatically, continuously and with high precision, and the product specifications are serialized, finalized and matched. The dimensions of each part are accurate.

）结构设计、详图设计、计算机模拟安装、工厂制造、工地安装等以较小时间差同步进行。

）Structural design, detail design, computer simulation installation, factory manufacturing, site installation, etc. shall be carried out synchronously with a small time difference.

）基础以上干式工法没有湿作业，内装饰等易于一次到位。型材经过镀锌、涂层后外观优美且防腐，有利于减少围护和装修用度。

）The dry construction method above the foundation has no wet operation, and the interior decoration is easy to be in place at one time. After galvanizing and coating, the profile has beautiful appearance and anti-corrosion, which is conducive to reducing the cost of enclosure and decoration.

）便于扩大柱距和提供更大分隔空间，可降低层高和增加建筑面积（住宅实用面积可达92%）。在增层、改造、加固方面上风明显。

）It is convenient to expand the column spacing and provide greater separation space, reduce the storey height and increase the building area (the practical area of residence can reach 92%). It has obvious advantages in storey addition, transformation and reinforcement.

）新墙材应用范围广，大量使用采光带，透风条件好。

）The new wall materials have a wide range of applications, a large number of daylighting belts are used, and the ventilation conditions are good.

）室内水热电气管线全部隐蔽在墙体中和楼层间，布置灵活，修改方便。

）All indoor hydrothermal electrical pipelines are concealed in the wall and between floors, with flexible layout and convenient modification.

）屋子可以搬迁、材料可全部回收利用，不会造成垃圾，符合可持续发展战略。

）The house can be moved and all materials can be recycled without causing waste, which is in line with the sustainable development strategy.