Towards Post-Carbon Cities: Which retrofit scenarios for hotels in Italy?

The building sector plays a crucial role in the advocated transition towards a carbon-free economy, and thus the zero-carbon building concept is taking hold. The paper focuses on the issue of existing hotels, with the aim of investigating the possibility of meeting the ambitious zero-carbon targets for this category of buildings, in which guests’ comfort and satisfaction is the core business. A reference hotel and different retrofit scenarios are assessed in two Italian climatic zones. Models are evaluated with a multiobjective approach, by introducing a set of hotel-related Key Performance Indicators (KPIs), to evaluate the simulated models on three main dimensions: thermal comfort, energy and environmental impacts. The obtained results have emphasized the difficulty to achieve the zero-carbon targets, due to the high energy consumptions caused by the comfort-based nature of hotels and of the space constraints for onsiterenewable sources. These outcomes help highlighting the need to shift the focus from single buildingto district or city scale, proving that the zero-carbon building definition must go hand-in-hand with the Post-Carbon City concept.