Low-cost survey solutions to support HBIM - Two case studies: the Azurém Canteen and Paço dos Duques in Portugal

Heritage Building Information Modelling is strongly connected with the need for accurate surveys, both because BIM models are not usually available and because of the historical buildings’ peculiarity. But acquiring those data demands the involvement of additional costly stakeholders, and that limits the widespread use of LiDAR technologies. New smart devices supplied with this technology may allow customers to acquire point clouds with a different approach, giving us more and more possibilities of easily acquiring a point cloud, possibly omitting the use of expensive equipment and the stakeholders (the surveyors) involved in their use; for example, the latest hardware installed by Apple on their devices come equipped with a LiDAR sensor and their patented True Depth algorithm, offering cheap alternatives in acquiring 3D scans. This thesis wants to deal with the comparison of different approaches of acquiring a point cloud, by exploring multiples possibilities and risks of using this new technology, starting from a review of the scientific literature on the subject, and then comparing the results of the different methodologies by using different point clouds realized by devices in three price range (namely a BLK2GO, a LEICA P20 laser scanner and an iPhone 12 PRO) using a series of buildings as case studies, focusing on heritage buildings. For this purpose, a series of scans will be analysed metrically and quantitatively, to understand their accuracy and recognize which level of accuracy (LOA) can be reached, and so understand which purpose this new low-priced technologies can be used for.