The systematization of technical information about architectural heritage in historic district by Citygml-Based Models. Preliminary activities towards digital recovery plans

Today, some historic centres of small cities exhibit high levels of obsolescence and abandonment, determined by the slow process of recovery and management. This is a consequence of some challenging issues: i) the plurality of technical and administrative users involved in, ii) the difficulty in recognizing the consistency of the built environment and its related values, and iii) the fragmentation of available regulatory contents for technicians. To support the structuring of recovery processes, this paper proposes the setup of a Thematic Digital Model (T-DM) for collecting, managing, and sharing technical knowledge, organized according to the CityGML standard. The systematization of the related contents in the model is structured as a preliminary activity to support the setup of digital recovery plans for historic districts, in a multi-disciplinary and dynamic way, while focusing on the physical properties of architectures in this work. Starting from a preliminary analysis of the regulatory framework, past experiences, and CityGML standard rules, the contents are identified and organized in a relational database for the enhancement of the three-dimensional T-DM. Moreover, the model has been tested on a pivotal case study, including its final fruition as a web service where the accesses are diversified coherently with the main purposes of data visualization.