Scan-to-BIM method in construction: assessment of the 3D buildings model accuracy in terms inventory measurements

Laser scanning 3D technology is gaining prominence in Architecture, Engineering and Construction, aiming to organize space and shape the human environment. Main advantages of laser scanning, such as efficiency, high accuracy and precision, low time consumption, safety, and non-invasiveness, provide technological support for sustainable development goals. Obtaining a point cloud using laser scanning and creating 3D models allows producing a highly detailed computer image of a measuring facility. The resulting spatial model of the building makes it possible to prepare inventory documentation, conduct construction analyses, and widely support technical facility management. The use of detailed data about a single building is becoming possible to enrich BIM (Building Information Modelling) or GEOBIM (geospatial environment with BIM). The present paper discusses the measurement and modelling of buildings using both terrestrial laser scanning. As an auxiliary method, close-range photogrammetry was carried out from an unmanned aerial vehicle. For this purpose, models were created of three facilities located in Poland. Particular attention was drawn to analysing potential errors in mapping. Direct geometry measurements were performed, and statistical analyses, deviations of actual lengths were specified. The results obtained have indicated that the measurement accuracy of existing buildings and its digital model is better than ±1 cm.