Prefabrication Rate in Housing Industrialization

The prefabrication rate in housing industrialization is an important indicator for measuring the degree of building industrialization, with its calculation methods and definitions varying across different scenarios. The following provides an explanation from two aspects: the general definition and calculation method, and the calculation rules for prefabrication rates in Shenzhen's residential industrialization projects.

General Definition and Calculation Method The prefabrication rate refers to the volume ratio of the concrete used in prefabricated concrete components of structural elements above the ±0.000 elevation of a building to the total concrete volume used. The calculation formula is: Prefabrication Rate = V1 / (V1 + V2) × 100% Here, V1 represents the volume of prefabricated concrete components in structural elements above the ±0.000 elevation of the building, covering types such as shear walls, extended wall panels, columns, supports, beams, trusses, roof trusses, floor slabs, stairs, balcony slabs, air conditioning slabs, parapets, and canopies. V2 represents the volume of cast-in-place concrete components at the same elevation. This definition focuses on the prefabrication ratio of structural elements, reflecting the industrialization level of the building's main structure, and is applicable to general calculation scenarios in most regions.

Calculation Rules for Prefabrication Rates in Shenzhen's Residential Industrialization Projects Shenzhen has a more detailed definition of the prefabrication rate, emphasizing the prefabrication ratio of specific parts of standard floors. The calculation formula is: Prefabrication Rate V = (Total Volume of Prefabricated Concrete Components on Standard Floors) ÷ (Total Volume of All Concrete on Standard Floors) × 100% The specific rules are as follows:

1. Calculation of the Total Volume of Prefabricated Components on Standard Floors:
   • The total volume of prefabricated concrete components of the main structure and enclosure is multiplied by a coefficient a=1 (e.g., prefabricated shear walls, columns, etc.).
   • The total volume of prefabricated concrete components of non-load-bearing internal partitions is multiplied by a coefficient b=0.5 (e.g., lightweight partition panels), and must meet the restriction condition that Non-load-bearing Internal Partition Prefabrication Volume × b / Total Volume of All Concrete on Standard Floors ≤ 7.5%.
2. Calculation of the Total Volume of All Concrete on Standard Floors: This includes the prefabricated volume of the main structure and enclosure, the prefabricated volume of non-load-bearing internal partitions (adjusted by the coefficient), and the volume of cast-in-place concrete. These rules more precisely guide the prefabricated application of non-load-bearing components by introducing coefficients and proportional restrictions, while avoiding the impact of excessive prefabrication on building functionality or economy. They are applicable to the special assessment of residential industrialization projects in Shenzhen.

The core difference between the two calculation methods lies in the fact that the general definition covers all structural elements, while Shenzhen's rules distinguish between component types and set coefficients, placing greater emphasis on the balance between functionality and economy on standard floors. In practical applications, the corresponding method should be selected based on the project's location and regulatory requirements.