Unmanned Aerial Vehicle (UAV)-Based Precision AS-Built Surveying for Institutional Buildings

Abstract

This study presents a 3D as-built survey of newly constructed laboratory buildings at Bells University of Technology using Unmanned Aerial Vehicle (UAV) technology. As-built surveys are essential for documenting deviations between original engineering designs and the actual constructed features. The objectives of this research include acquiring aerial imagery via UAV, identifying both natural and manmade features within the project area, generating a high-resolution orthophoto, and evaluating the as-built data against the original architectural design. The methodology employed GPS and UAVs for spatial data acquisition, alongside digital processing tools such as Agisoft Metashape Professional, AutoCAD Carlson 2021, and Agisoft Viewer for modeling and analysis. Comparative analysis between architectural and observed measurements revealed minimal deviations, ranging from 0 cm to 9 cm. Overlaying the final building footprints on Google Earth further confirmed spatial accuracy. The findings demonstrate that the constructed structures closely align with the intended design, validating the reliability of UAV-based 3D as-built surveys. This research highlights the effectiveness of UAV technology in producing accurate, cost-efficient, and timely documentation for construction verification, facility management, and future planning.