A 3d platform for energy data visualization of building assets

With an exemplary role, the improvement of energy efficiency in public buildings is in the forefront of the European policies for smart and sustainable growth. However, very often the sector is characterized by large and old constructions that may also be marked by historical and cultural value and whose energy consumption is hard to be reduced, due to specific constraints. In order to operate in this field, the definition of a solid knowledge framework on the built environment appears to be the only viable starting point. Therefore, the analysis of the delicate balance between conservation and transformation should be investigated with a multiscalar approach able to move from the city to the building elements. For this reason, it is extremely important to provide tools for monitoring and analysing the energy behaviour of the public building stocks to those actors that are involved in their management. The research here presented proposes a workflow to implement a web platform based on a three-dimensional GIS (Geographic Information System) interoperable with BIM (Building Information Modeling) and able to store, handle and display information on building assets and their energy consumption. With the aim of defining a repeatable model, the process starts from easily retrievable data on the built environment and uses standard data models and classification systems. The threedimensional model is built in a semi-automated way from the combination of the twodimensional GIS cartography of the municipality and from the point cloud resulting from a LiDAR (Light Detection And Ranging) national survey campaign. The set of thermal properties and energy data can be retrieved from the energy performance certificate of the buildings. In order to test and validate the process, an application on the building stock owned by the University of Pavia (Italy) is presented. Nine complexes distribute inside the historical centre of the city and heterogeneously dated from the X to the XX century are considered. After the definition of the model and its representation inside the web environment, an example of use is displayed with reference to a comparative energy analysis of different buildings.