The research presented in the article focuses on the development of methodological protocols - from survey to digital reconstruction - for the enhancement and protection of built heritage. Through the realisation of virtual reality-based digital models, it is possible to narrate the evolution and transformation of those places that constitute our historical memory. The European Project H2020 Prometheus, focused on the documentation of the Gdańsk fortresses Route, allowed applying these strategies to the Port Battery case study, presented in this paper. The coastal battery, built in the 19th century, is a brick ruin located in the restricted port area of Gdańsk, witness to several historical processes of transformation. To be able to represent the evolution of the building through history, the operational method regarded the digital acquisition of the building to obtain a detailed model representing the state of the battery. Then the archive research and the available historical maps allowed not only to make a comparison between the previous stages of construction and the actual situation but also to digitally reconstruct what has been destroyed. In this way, through Virtual Reality via Head Mounted Display it is possible to obtain an immersive, but accurate, experience of the digital reconstruction being able to re-live the history of a place.

Digital 3D reconstruction in architecture is a powerful tool for monitoring construction sites, tracking project progress, and ensuring quality control. This method involves the use of digital survey technologies, such as drones, laser scanners, and 3D modelling software, to acquire precise and detailed data on the construction process. If we consider surveying to be a phase of documenting the existing, it is possible to talk about an architectural census as the process of collecting and analysing data on buildings and structures. This information is crucial for management and planning, as it can help identify issues related to building safety, accessibility, and sustainability. The research project aims to quickly obtain a database of documentation and historical, dimensional, morphological, and material knowledge of a university building in the historic centre of Pavia that is now disused, to develop an information system for quick census and monitoring.

This research aims to define a low-cost replicable methodology for obtaining fast multiscale information models. The experiments carried out were conducted by researchers from Dada LAB and PLAY experimental Laboratories of the University of Pavia, Department of Civil Engineering and Architecture, on the case study of the irrigated landscape of the Pavia plain. The entire work process was developed according to a low-cost purpose, starting from fast acquisition activities with UAV instruments, to the processing of photogrammetric data, urban and detailed scale modelling with open-source software, to the census, filing, and computerisation of the model. The resulting product is configured as a multiscale reality-based information system. A census card is associated with each constituent element of the model (crops, canals, valuable hydraulic artefacts). Connection to the GIS platform allows the user to query the model. The result is a digital system oriented to facilitate the management of the agricultural and irrigation landscape, and to digitally document and preserve the heritage of historical hydraulic existing artefacts. Two different GIS platforms for structuring the information system were tested. The first involved a high-budget solution using ESRI ArcGIS Pro/ArcSCENE software, and the second involved using QGIS software, an Open-Source Geographic Information System, to develop an accessible information system without license fees, to evaluate the advantages and disadvantages of low-cost processes.

This paper presents a critical review of fast survey methods and tools applied to the documentation of historical city centers, with a focus on Pavia. Within the framework of the DORIAN project, which aims to create a Digital Twin of the city, the research evaluates different Mobile Laser Scanner (MLS) and SLAM-based technologies, along with kinematic terrestrial laser scanners, to achieve metric accuracy in reduced acquisition times. The experimentation was conducted on the Cairoli University College and its adjoining square, providing diverse conditions for testing both indoor and outdoor environments. The study demonstrates the potential of these methods to support the conservation and valorization of architectural heritage while enabling sustainable urban planning. Ultimately, the developed 3D database represents the foundation for the future Digital Twin of Pavia’s historical city center, serving as an interoperable infrastructure for research, management, and resilience strategies.