TITLE:
Contribution of 3D and 7D BIM to the Diagnostic Assessment of the Former National Council of Shippers of Benin Building (G + 4) in Cotonou
AUTHORS:
Kassa Issifou Mounou Sambieni, Blandine Gloria Fifamè Accrombessi, François de Paule Codo
KEYWORDS:
Diagnostic, 3D, 7D, Scan-to-BIM, R + 4, Autodesk Revit, Cotonou
JOURNAL NAME:
Open Journal of Applied Sciences,
Vol.16 No.9,
September
16,
2026
ABSTRACT: In Benin, the diagnostic assessment of public buildings is hindered by the rapid aging of the building stock and the near-total absence of as-built drawings, limiting the scope of traditional diagnostic methods, based on visual inspection, site surveys and isolated tests, but poorly structured and difficult to use over time. This study aims to integrate BIM into this process, using the former National Council of Shippers of Benin building, a structure of type R + 4 with basement, in Cotonou, as a case study. The approach combines visual inspection with a Scan-to-BIM workflow. A 3D laser scan survey enabled the reconstruction of the building’s geometry in Autodesk Revit, representing the 3D dimension of BIM. Semantic enrichment through a custom property set integrated diagnostic data into the model prior to IFC 4 × 3 export and visualization in BIMcollab Zoom, representing the 7D dimension dedicated to operation and maintenance. Structural verification of load-bearing elements followed the BAEL 91 (amended 1999) regulations, with cross-validation through Revit-Robot Structural Analysis interoperability. Nine non-structural defects were identified and located on the digital model. Significant structural deterioration was observed in the beam supporting the skylight at level R + 4, whose actual depth of 33 cm does not meet the 40 cm minimum required by the manual calculation, both methods nonetheless converging on the same steel cross-section of 1.57 cm2. The associated column was found compliant, with 4HA12 reinforcement. These results propose a reproducible protocol combining traditional diagnosis with the 3D and 7D dimensions of BIM, supporting sustainable digital management of Benin’s public building heritage.