What is Change-of-Use Structural Assessment?

In the building inspection industry, "Change-of-Use Structural Assessment" typically refers to a comprehensive assessment and evaluation of the structural safety, suitability, and durability of a building before its function is changed (e.g., converting a residential building to a commercial building, or a factory to a school). The purpose of this inspection is to ensure that the building still meets relevant safety codes and standards under the new usage conditions.

Importance of the Inspection

Changing the use of a building usually means that the building's load, occupancy density, and usage environment will change. For example:

• Increased load: Offices typically need to withstand greater live loads (furniture, equipment, personnel) than residential buildings.

• Higher safety requirements: Public places such as hospitals, schools, and large shopping malls have higher safety requirements for fire protection, evacuation, and seismic resistance.

• Structural impact: Demolition, additions, or expansions to the original structure may affect the overall structural safety.

Therefore, professional inspection and assessment are necessary to evaluate whether the existing structure can withstand the new usage requirements and to propose necessary reinforcement or renovation suggestions.

Main Inspection Contents

"Change of use inspection" involves multiple aspects, usually including the following:

• Review of original documents: Verify the original design drawings and construction documents based on the current state of the building to understand the building's "health record."

• On-site investigation and surveying: Investigate the actual use and environment of the building, and conduct necessary structural dimension verification and surveying.

• Material performance testing: Use non-destructive testing or local sampling to test the actual strength and performance of the main structural materials such as concrete, steel, and masonry.

• Structural damage detection: Check for cracks, deformation, corrosion, and other defects and damage in the structure, and analyze the causes and extent of the damage.

• Structural analysis and load-bearing capacity calculation: Based on the new usage function and load standards, establish a structural calculation model to verify the load-bearing capacity, stiffness, and stability of the structural components, and assess whether they meet the requirements of the new use.

• Reliability assessment: Conduct a comprehensive assessment of the safety, serviceability, and durability of the structure.

Standards and Regulations

In China, this type of testing typically follows a series of national and local standards, such as:

• "Technical Standard for Building Structure Testing" (GB/T50344-2019)

• "Standard for Structural Testing and Evaluation of Existing Buildings" (local regulations, such as Shanghai Municipal Engineering Construction Standards)

• "Standard for Reliability Assessment of Civil Buildings" and other relevant regulations.

Process

The general process for "change of use testing" includes:

• Commissioning and Negotiation: The owner commissions a testing and appraisal agency with the appropriate qualifications.

• Scheme Development: The testing agency develops a detailed testing plan based on the client's requirements and on-site conditions, which may require expert review if necessary.

• On-site Implementation: On-site data collection, material sampling, and testing are conducted according to the plan.

• Data Analysis and Calculation: The testing data is analyzed, and structural calculations are performed.

• Report Issuance: The testing agency issues a formal "House Safety Appraisal Report" or "Structural Testing Report," clearly stating the conclusions and providing recommendations for treatment (such as reinforcement or repair).

• Administrative Approval: The owner applies to the local planning and construction authorities for approval of the change of use based on the report.