National Standard Size Diagram of Prefabricated Houses
Currently, there is no directly published national standard size diagram for prefabricated houses, but relevant design requirements can be indirectly understood through the standard sizes of prefabricated components and industry specifications.
Common Size Ranges of Prefabricated Panels
One of the core components of prefabricated houses is the prefabricated panel, whose size directly affects the structural layout of the house. According to industry specifications, the span of residential prefabricated panels typically does not exceed 4.2 meters, a limit primarily based on balancing structural safety and material performance. Excessive spans increase the self-weight of the components and transportation difficulties, while also imposing higher requirements on the load-bearing capacity of connection nodes. In terms of width, 500mm and 600mm are mainstream specifications, which can meet modular assembly requirements and facilitate on-site hoisting operations. Thickness design mainly focuses on 120mm and 150mm, with the former suitable for non-load-bearing partition walls or lightweight floor slabs, and the latter mostly used for load-bearing structures, requiring calculations to verify whether their flexural and shear resistance performance meets the requirements of the "Code for Design of Concrete Structures" (GB 50010).
Refinement of Prefabricated Components by Local Standards
Some regions have issued standard atlases for prefabricated components of prefabricated buildings, such as the four atlases approved by Sichuan Province, including the "Standard Base Plate for Prestressed Concrete Steel Pipe Truss Composite Slabs." Although these atlases do not disclose specific size diagrams, they clarify standardized parameters for components, such as the truss height and reinforcement spacing of composite slabs, providing reusable technical templates for design units. Enterprises can develop prefabricated house products that comply with local specifications based on such atlases, but it should be noted that the applicable scope of the atlases is usually limited to specific climatic zones or seismic fortification intensity regions, and recalculations are required for cross-regional use.
Core Principles of Size Design
The size design of prefabricated houses should follow the principle of "modular coordination," that is, using 300mm as the basic module (M=300mm) to achieve the versatility of components through modular combinations. For example, the house bay can be designed as 3M (900mm), 4M (1200mm), etc., and the depth direction can adopt multiples of 6M (1800mm), which can not only reduce the types of components but also minimize construction errors. At the same time, size design should take into account transportation limitations. The height limit for highway transportation in China is 4.5 meters (including vehicle height), so the single-story height of prefabricated houses typically does not exceed 3.3 meters, and the total height should be controlled within 14 meters (calculated based on 4 stories).
