Prefabricated Prefab Component Housing

Prefabricated prefab component housing is a building form that involves industrial production of building components and on-site assembly. It offers advantages such as shortened construction periods and reduced pollution, but also has limitations in terms of design flexibility and transportation and hoisting.

I. Definition and Types Prefabricated prefab component housing, also known as prefabricated buildings, centers on the prefabrication of building components (such as beams, slabs, walls, and columns) in factories, followed by transportation to the site for mechanical connection or assembly to complete the main building structure. Based on the component combination method, there are three main types:

1. Panel-based Prefabrication: This type primarily uses flat components such as prefabricated wall panels and floor slabs, connected through bolts or welding. It is suitable for multi-story residential buildings or factories. For example, the fully prefabricated rural houses in Jiangbei, Ningbo, adopt a panel structure, with the main structure installation taking only 7 days.
2. Box-based Prefabrication: Functional units such as bathrooms and kitchens are prefabricated into "boxes" and then spliced on-site to form a complete building. This method can increase construction speed by 50%-70%, but it has higher requirements for transportation and hoisting equipment.
3. Frame-based Prefabrication: This type uses prefabricated concrete or steel frames as supports, filled with prefabricated wall panels or floor slabs. It is suitable for high-rise buildings and offers greater flexibility.

II. Technical Systems and Materials The technology covers two main directions: prefabricated concrete structures and steel structures. Concrete structures reduce on-site wet work through prefabricated components, while steel structures enhance construction efficiency with their lightweight and recyclability. Component types include prefabricated beams, columns, composite slabs, stairs, etc. Some projects adopt the "equivalent to cast-in-place" design concept to ensure structural safety consistent with cast-in-place buildings.

III. Advantages and Applications

1. Efficiency Improvement: Industrial production reduces reliance on on-site labor. The main structure installation period for the rural house project in Ningbo was shortened to 7 days, and the construction speed of box-based prefabrication increased by 50%-70%.
2. Environmental Benefits: It reduces construction waste, dust, and noise pollution, aligning with the trend of green building development.
3. Large-scale Application: After the 21st century in China, companies like Vanke have developed prefabricated shear wall residential systems and promoted prefabricated frame technology in affordable housing and commercial buildings.

IV. Limitations

1. Design Flexibility: Panel-based prefabrication is limited by component standardization, making it difficult to adjust floor plans.
2. Transportation and Hoisting: Box-based prefabrication requires large transportation vehicles and hoisting equipment, increasing costs and construction difficulty.
3. Connection Node Quality: Mechanical connections (such as bolts and sleeve grouting) have high requirements for construction accuracy and require strict quality control.