Light steel structure is a young and energetic steel structure system, which has been widely used in general industrial and agricultural, commercial and service buildings such as office buildings, villas, warehouses, stadiums, entertainment, tourism buildings, low-rise and multi-storey residential buildings, etc. It can also be used for layer addition, renovation, reinforcement and lack of building materials in old houses, areas with inconvenient transportation, tight construction periods, and high activity buildings. Small footprint. Components are automated, continuous, high-precision production, product specification serialization, molding, matching. The dimensions of each part are accurate. Structural design, detailed design, computer simulation installation, factory manufacturing, on-site installation, etc. Take the smaller the smaller.

There is indeed no uniform standard to determine the structure of heavy steel and light steel structures. Experienced designers or project managers often cannot fully understand, but we can comprehensively consider and judge some data:
1. The lifting weight of the workshop: greater than or equal to 25 tons, it can be regarded as a heavy steel structure.
2. Steel consumption per square meter: greater than or equal to 50KG/M 2. It can be regarded as a heavy steel structure.
3. The thickness of the steel plate of the main component is greater than or equal to 10MM, and the light steel structure is used less.
In addition, there are some reference values: such as cost per square meter, maximum component weight, maximum span, structural form, eaves, etc. The above can provide empirical data when judging whether the factory is heavy steel or light steel. Of course, many buildings are now Light steel, heavy steel. But some we can definitely say are heavy steel: such as: petrochemical plant facilities, power plants, large-span stadiums, exhibition centers, high-rise or super high-rise steel structures.
In fact, national specifications and technical documents are not heavy steel. In order to distinguish light-duty residential steel structures, ordinary steel structures can be called ordinary steel. Due to the wide range of ordinary steel structures, which can include various steel structures, regardless of the size of the load, or even many contents of light steel structures, the technical regulations for light-weight residential steel structures only stipulate some more specific content and scope for their light characteristics. Only for single door frame.
Light steel is also a vague term that generally has two understandings. First, in the current "Code for Design of Steel Structures" (G**17-88), Chapter 11 "Light steel structures with round steel and small angle steel" refers to the use of round steel and smaller than L45*4 and L56*36*4 The light steel structure made of angle steel is mainly used for small structures that are not suitable for reinforced concrete structures when there is a lack of reinforced concrete structures. The other is the single-layer solid-web door rigid frame structure with light roof and light exterior wall (masonry exterior wall can also be used conditionally) stipulated in the Technical Specifications for Steel Structure of Single-layer Solid Web Door Houses. Lightweight here mainly means that the shell is made of lightweight materials. Since the former was quickly cancelled, the meaning of light steel now mainly refers to the latter.
It can be seen that the difference between light steel and ordinary steel is not the weight of the structure itself, but the weight of the envelope material, but the concept of structural design.