Prefabricated Perforated Panel Brick-Concrete House

Prefabricated perforated panel brick-concrete houses were widely adopted in Chinese cities from the 1970s to the 1990s. These buildings feature a mixed load-bearing structure consisting of brick walls and prefabricated perforated panel floors, presenting safety hazards such as poor earthquake resistance and weak structural integrity, necessitating scientific disposal based on the current condition of the houses and policy requirements.

Construction Background and Structural Characteristics

Prefabricated perforated panel brick-concrete houses emerged between the 1970s and 1990s. Limited by the financial and technological conditions of the time, their design and construction were relatively rudimentary. Structurally, brick walls serve as the main vertical load-bearing elements, while horizontal load-bearing components are made of cement-prefabricated perforated panels, which are joined together to form the floor. This structure offers advantages such as easy material sourcing, low cost, good durability, and fire resistance, but it also has significant drawbacks:

1. Poor Earthquake Resistance: Brick walls may collapse if they deform by more than 2 centimeters, leading to a high damage rate during earthquakes. For example, 75% of brick-concrete houses developed cracks in the Jishishan earthquake in Gansu, while data from the Ludian earthquake in Yunnan and Japan showed a 15% damage rate for prefabricated panel houses.
2. Weak Structural Integrity: The numerous joints in the prefabricated panels, resembling “building blocks”, result in poor overall structural integrity, making the houses susceptible to structural damage from external impacts or aging.
3. Construction Quality Hazards: The use of substandard materials and rough construction techniques in the early stages further exacerbated the durability issues of these houses.

Safety Hazards and Risks

Improper use can accelerate the aging of these houses, such as removing or altering load-bearing walls, illegal construction, or changing the intended use, which may directly undermine structural stability. Additionally, natural aging of the houses leads to the degradation of material properties, which, combined with original design flaws, gradually reveals safety hazards. According to the 2026 Ministry of Housing and Urban-Rural Development survey, over 120,000 D-grade dilapidated houses (with prefabricated panel houses accounting for over 60%) still require disposal nationwide, highlighting the urgent risks associated with these structures.

Renovation Policies and Directions

For prefabricated perforated panel brick-concrete houses, policies focus on a “retention, renovation, and demolition” approach, emphasizing classified disposal:

1. Complete Demolition and Reconstruction: Applicable to residential communities built before 2000 that use perforated panel materials and pose significant safety hazards (as per Zhejiang policy), or to prefabricated panel houses identified as D-grade dilapidated structures (as per the 2026 Ministry of Housing and Urban-Rural Development notice).
2. Reinforcement and Renovation: For non-D-grade dilapidated houses, priority is given to enhancing earthquake resistance through reinforcement to extend their service life.
3. Time Limits: Complete demolition and reconstruction projects may be allowed up to 3 years for completion, while demolition-renovation combination projects and planned new construction projects are expected to be completed within 2 years, and integrated improvement projects are to be completed within 1 year in principle.

The policies also limit the scale of demolition, requiring that the floor area demolished within urban renewal units should not exceed 20% of the current total floor area, avoiding large-scale demolition and construction, and balancing safety needs with resource conservation.