The paper presents one of the case studies of the Research of National Interest MIUR PRIN COFIN 2008 “Complex models for architectonic and urban heritage”, principal investigator Prof. Mario Centofanti, Architecture and Town Planning Department, University of L’Aquila. Subject is the palazzo of Margherita d’Austria (XIV-XIX centuries), town hall of L’Aquila city, in 2009 seriously damaged by the seismic events. The building has been surveyed by integrated method, also using laser scanning. Elaborations are about constructive elements, degradation phenomena, ruins, etc. A three-dimensional digital model has been realised according to the architectonical surveying, with a level of detail corresponding to a representation scale 1:50. This study analyses the utility of the 3D model for the restoration project. The digital model assists a simulation of architectonic reality, according to a knowledge’s rule of the model that enriches our experience: the model simulates geometries, spaces, materials, architectural characteristics, etc. That is the image of architecture. About the knowledge process, the correlation of the model with an architectonical informative systems allows surveying’s data collection and systematization. These data are numerous and heterogeneous, concerning different aspects, from measurements to textual information. In particular the model facilitates the analysis of archival documents with their spatial relation to architectonic components. Besides the model favours historical-critical studies, in particular with the visualization of synchronic-historical sections, with metrological, proportional and spatial analysis, with elaborations about materials and conservation conditions. At the same time, in a mirror-like point of view, the model offers a support to the planning process, with the imulation, development, verification and definition of the restoration project in advance.