Evaluation Criteria for Prefabricated Houses

The evaluation criteria for prefabricated houses are primarily based on the 'Standard for Appraisal of Dangerous Buildings' (JGJ 125 - 2016) and the Beijing local standard 'Standard for Comprehensive Safety Appraisal of Building Structures' (db11/t 637 - 2024), as detailed below:

I. 'Standard for Appraisal of Dangerous Buildings' (JGJ 125 - 2016) This standard divides building safety into four grades, providing a basic framework for the safety assessment of prefabricated houses.

• Grade A: No dangerous components; the structure meets safety requirements for use. This means the overall structure of the house is intact, with all components functioning normally and no safety hazards present, allowing for normal occupancy or use.
• Grade B: Some components are dangerous but do not affect the safety of the main structure. For example, cracks in some non-load-bearing walls, while problematic, do not pose a threat to the overall structural stability of the house.
• Grade C: Some load-bearing structures do not meet safety requirements for use, with local areas in a dangerous state. For instance, severe deformation or cracks in some load-bearing beams or columns affect local structural safety, necessitating timely reinforcement or repair measures.
• Grade D: The load-bearing structure no longer meets safety requirements for use, with the entire house in a dangerous state. At this point, the house poses serious safety hazards and may collapse at any time, requiring immediate cessation of use and demolition or large-scale renovation.

II. 'Standard for Comprehensive Safety Appraisal of Building Structures' (db11/t 637 - 2024) This standard was implemented on October 1, 2024, and is applicable to the comprehensive safety appraisal of prefabricated house structures in Beijing.

• Comprehensive coverage: It includes general provisions, terms and symbols, basic requirements, investigation and testing, site and foundation, various types of structural buildings (masonry structures, concrete structures, steel structures, timber structures, etc.), bottom-frame brick buildings and internal-frame buildings, building structural safety, seismic and structural comprehensive safety appraisal ratings, etc.
• Strong targeting: For prefabricated houses of different structural types, detailed appraisal methods and rating standards are formulated to provide a more comprehensive and accurate assessment of the comprehensive safety of building structures.