Service Life of Prefabricated Panel Houses

The designed service life of prefabricated panel houses is uniformly set at 50 years. After expiration, they can still be inhabited if they pass professional appraisal, and their actual safety needs to be judged after determining the grade through professional appraisal.

According to the current national standard, the Unified Standard for Reliability Design of Building Structures (GB 50068-2018), the designed service life of ordinary residential buildings (including prefabricated panel buildings) is 50 years. This period is a reference cycle under the premise of normal design, construction, use, and maintenance, during which the main structure of the building can be used normally without major repairs, and it is not a mandatory scrapping period. After the 50-year period, if the building passes the appraisal by a professional institution, it can still be inhabited. Among the prefabricated panel buildings that have completed safety assessments nationwide, approximately 72% have been rated as Grade A or B, indicating that their main structures are safe and can be inhabited normally.

The actual safety of a building needs to be graded through professional appraisal, which is divided into four grades according to the Standard for Appraisal of Dangerous Buildings (JGJ 125-2016):

• Grade A: The structural bearing capacity meets normal use requirements, with no dangerous components, and can be inhabited normally;
• Grade B: Some components are aged, but they do not affect the main structure, which is basically safe and can support normal life;
• Grade C: Some load-bearing structures are damaged, constituting a partially dangerous building, which requires professional reinforcement before inhabitation;
• Grade D: The load-bearing structure fails, making the entire building dangerous, which needs to be stopped from use and demolished.

The claim of a '30-year lifespan' originates from early references to the designed service life of temporary buildings or simple houses, or misuse of the '25-year lifespan for easily replaceable building structural components,' and has no relation to the design standards of formal prefabricated panel residential buildings. The actual lifespan of a building is influenced by factors such as construction quality, later maintenance, and usage patterns, rather than solely determined by its age. For example, a prefabricated panel house that is regularly maintained may far exceed a 50-year lifespan, while a house that lacks long-term maintenance may develop safety hazards prematurely. Therefore, the core basis for judging whether a building can continue to be inhabited is the result of professional appraisal, rather than the designed service life or age of the building.