Inspection and Appraisal of Prefabricated Houses

The inspection and appraisal of prefabricated houses primarily involve safety inspections covering three major aspects: structural safety, public facilities, and unauthorized modifications, with professional institutions issuing reports and classifying levels based on standards.

I. Inspection Content

1. Structural Safety: Professional inspectors focus on key components such as foundations, walls, floors, and steel reinforcement. For example, foundation settlement or cracking may affect overall stability; wall cracks, deformation, or through-cracks at prefabricated panel joints require vigilance for structural damage; floor deflection or a noticeable springy feel when stepped on may indicate insufficient load-bearing capacity; and steel reinforcement corrosion weakens structural strength. These indicators directly reflect the safety of the house's structure.
2. Public Facilities: Non-structural issues such as aging pipelines, waterproofing failure, and blocked fire exits are inspected. Prefabricated buildings, constructed early, may have plumbing and electrical design standards that cannot meet current usage intensity, leading to common issues like leaks, tripped circuits, and clogged drains; waterproofing failure can cause wall seepage and mold; and blocked fire exits threaten emergency evacuation safety. Although these issues do not directly cause building collapse, they seriously affect living safety and quality of life.
3. Unauthorized Modifications: Checks are made for unauthorized actions such as removing load-bearing walls, adding structures on rooftops, or converting balconies into kitchens or bathrooms. Such modifications alter the original load-bearing system of the house, for example, removing load-bearing walls may trigger partial or complete collapse; adding structures on rooftops increases loads, leading to overloading of floors or beams and columns; and converting balconies into kitchens may cause leaks due to improper waterproofing, even affecting structural safety.

II. Appraisal Process and Level Classification
After inspections, qualified professional institutions issue reports and classify levels into four categories based on the "Standard for Dangerous Building Appraisal" (JGJ 125 - 2016):

• Level A: No dangerous components; the structure meets safety requirements for use.
• Level B: Individual components are dangerous (e.g., local cracks), but do not affect the safety of the main structure.
• Level C: Some load-bearing structures do not meet safety requirements for use; parts are in a dangerous state (e.g., beam and column cracking).
• Level D: Load-bearing structures no longer meet safety requirements for use; the entire building is in a dangerous state (e.g., severe foundation settlement, risk of large-scale wall collapse).

III. Extended Significance of Building Inspections
Building inspections are a broader assessment process covering over 20 types, including structural safety, seismic resistance, condition grading, and chemical damage analysis, with inspection scopes including construction impact monitoring and historical building assessments. This process relies on CMA-certified institutions, forming a comprehensive assessment system through laboratory testing, structural calculations, and on-site monitoring, providing scientific bases for the safe use, renovation, expansion, and repair of buildings.