Prefabrication Rate of Prefabricated Housing

Shanghai stipulates that the prefabrication rate of individual newly-built buildings should not be lower than 40% (or the assembly rate of individual buildings should not be lower than 60%), but there are differences in the actual prefabrication rates among different technical systems and projects.

I. Basic Requirements for Prefabrication Rate in Shanghai Policies

According to relevant regulations in Shanghai, the prefabrication rate of individual newly-built buildings within the scope of prefabricated building implementation should meet the standard of not lower than 40%, or the assembly rate of individual buildings should not be lower than 60%. This requirement is a general regulation for prefabricated buildings across the city, aiming to promote the development of building industrialization. However, for special cases such as residential buildings over 100 meters, the policy allows for appropriate adjustments to the prefabrication or assembly rate indicators to balance building safety and industrialization goals.

II. Differences in Prefabrication Rates among Different Technical Systems

The diversity of technical systems in prefabricated buildings leads to significant differences in prefabrication rates:

1. Composite Shear Wall (PCF) System: The prefabrication rate is usually around 20%. For example, the Shanghai Vanke Golden Mileage project adopts this system, with an actual prefabrication rate of 16%, which is lower than the minimum policy requirement, possibly due to project positioning or technical optimization needs.
2. Cast-in-place External Wall System: The prefabrication rate is generally low. For instance, the Shanghai Fangxing Daning Jinmao Palace project has a prefabrication rate of 25%, suitable for building types with less demand for prefabricated components.
3. Prefabricated Monolithic Shear Wall System: The prefabrication rate varies widely. The project in the north plot of Xincheng Dijing in Changzhou, Jiangsu, has a prefabrication rate as high as 80%, while the Shanghai Vanke Pudong Haishang Chuanqi and Taihe Qingpu Hongqiao projects have prefabrication rates of 25% and 45% respectively, reflecting differences in the choice of industrialization level among different projects.
4. Prefabricated Monolithic Frame System: The prefabrication rate is mostly around 25%. For example, the Shanghai Greenland Hongkou Commercial and Office Building project adopts this standard.

III. Analysis of the Causes of Differences in Prefabrication Rates

Differences in prefabrication rates are mainly influenced by technical routes, project positioning, and policy flexibility:

• Technical Routes: Due to the limitations of component connection methods, the prefabrication rate of the composite shear wall system is difficult to significantly increase; while the prefabricated monolithic shear wall system can achieve a higher prefabrication rate through standardized design.
• Project Positioning: Commercial office buildings may focus more on construction efficiency and adopt a lower prefabrication rate; residential projects may increase the prefabrication rate to meet policy requirements or improve quality.
• Policy Flexibility: Shanghai's adjustments to indicators for special building types allow projects to balance safety and industrialization. For example, super high-rise residential buildings may reduce the prefabrication rate requirements due to structural complexity.