Prefabricated Panel House

A prefabricated panel house, also known as a prefabricated slab house, is a type of dwelling constructed primarily using prefabricated panels. The following provides an introduction from aspects such as its origin, characteristics, existing problems, and renovation policies.

Origin and Characteristics: Prefabricated slab houses originated in the early 20th century. In China, most residential buildings constructed before 1985 adopted this type of structure. The prefabricated panels are cement components made in factories. During production, wooden models are nailed together, steel bars are arranged, and cement is poured to form the panels. There are two types: solid and hollow. The hollow structure achieves lightweighting by reducing the non-load-bearing concrete. This construction method offers significant advantages, with fast construction speeds. Like building with building blocks, entire walls and floor slabs are transported from the factory and assembled by workers on-site.

Existing Problems:

• Weak Earthquake Resistance: Composed of individual prefabricated panels joined together, they lack robustness and flexibility. The hollow design and the less scientific arrangement and quantity of steel bars compared to cast-in-place houses make even slight vibrations likely to loosen the joints between floor slabs, making them unable to withstand seismic impacts during earthquakes.
• Limited Service Life: The service life is approximately 30 - 50 years. As time passes, problems gradually emerge. Many older prefabricated slab houses have been identified as "dangerous buildings," and repairs are difficult and costly.
• Wall Cracks and Water Leakage: Walls are prone to cracks, and ceilings may leak water, with the situation being more severe on the top floors. Additionally, sound insulation is poor.
• Poor Thermal Insulation: Thermal insulation performance is inadequate, making them hot in summer and cold in winter. During extreme weather, cold or hot air can easily seep in through gaps in the walls and around doors and windows.

Renovation Policies: Since 2022, China has implemented renovation policies focusing on repairing and upgrading prefabricated slab houses, with demolition only for buildings that meet the criteria for dangerous structures. For example, in a community in Fengtai, Beijing, old prefabricated slab houses were demolished and rebuilt into new houses with an earthquake resistance of magnitude 8, and elevators were added. Residents only need to pay 30% of the cost, with the government subsidizing the remaining 70%. By the end of 2027, all residential communities built before 2000 across the country are expected to complete such renovations.