Digitalizing historical buildings of Western Greece – from point clouds, to building information modeling and 3D printing

Cultural heritage worldwide is of great interest for general public and scientific communities across disciplines. In the Mediterranean region, and in Greece in particular, historic buildings and monuments are widespread. Ongoing environmental change, and the increased frequency and severity of climatic extremes and natural hazards in the Mediterranean regions, challenge the protection of cultural heritage, making essential the detailed documentation and digitalization of these monuments in tailored geodatabases. In the present study, example historical buildings of Western Greece were selected, covering a wide environmental gradient from coastal to mountainous landscapes, namely, a 19^th century emblematic stone-built lighthouse at Cape Drepano, close to Patras, in Northern Peloponnese, as well as historical buildings in the Aetolia-Acarnania region, including 19^th and 20^th century monuments in the lagoon region of Messolonghi (the Old Hatzikosta Hospital and the Palamas School), as well as a 18^th century post-Byzantine monastery located in a mountainous area near Agrinio. Geodetic field surveys were conducted with Terrestrial Laser Scanning (TLS) and Unmanned Aerial Vehicle (UAV) photogrammetry. The collected point clouds were processed to generate Building Information Models (BIMs) of the examined structures which were then 3D printed at scale. The derived digital database of these monuments offers a detailed documentation and baseline of the present status of these monuments. This baseline, when combined with future field surveys, set the basis for accurate monitoring of the response of these structures to natural and anthropogenic stressors (e.g., costal erosion, land displacement, etc.). Moreover, this documentation could assist the efficient planning of maintenance and restoration interventions, while the derived digital and printed 3D models offer tangible tools for raising public’s awareness and valorizing further these historical buildings. Technological advancements in geodetic instruments as well as the continuous development of numerical tools for BIM applications, 3D modeling and printing, facilitate the seamless digitalization of cultural heritage and its archiving into interactive geodatabases, complementing existing efforts towards coordinated documentation and monitoring of historical buildings at national and international levels.