Aerial thermography applications for energy conservation and retrofit of urban heritage

Cities are the main responsible for energy consumption and greenhouse gas emissions in Europe, with the European Union playing a key role in policy-making to address this issue by enhancing the current energy performance class. In this process it is to be acknowledged that restrictions on cultural heritage can obstruct the renovation process by preventing transformations, thus requiring policymakers to find a trade-off which balances conservation and energy retrofit targets. Infrared thermography can support the assessment process on multiple scales. By crossing estimated data on indoor temperatures and thermographic images it is possible to define the thermal dispersion of the building envelope, then correlating it to the energy performance class for planning interventions. A real application on a district in Turin, Italy, is presented. It aimed at creating a hybrid Urban Building Energy Model based on aerial thermographic images and statistical data gathered through the Certificates of Energy Performance and the national population census. The current state was defined before comparing two alternative renovation scenarios which considered alternative energy performance parameters and energy supply options. Specific insights can be produced on protected assets of the district area, thus enabling conclusions targeting an optimal trade-off between conservation and renovation.