Decarbonization, robustness and resilience: the challenges of future buildings. The Dammusi of Pantelleria Island, a case study. =

Due to their relevant energy and environmental impact, buildings are recognized among the main causes of climate change. Consequently, buildings must undertake the decarbonization process, which is one of the most decisive solutions to curb, to achieve the sector transition, which will be guided by higher electrification of end-uses and deployment of renewable energy sources. Furthermore, future buildings performance, in terms of energy needs and occupants’ comfort, will inevitably be affected by a wide range of foreseeable and unforeseeable events during the operational phase (e.g., energy supply interruptions, external air temperature increase, natural events, occupants’ habits, etc.). Therefore, the design of new constructions and the retrofit of existing buildings cannot be performed with the sole objective of achieving high energy performances, but it asks for the introduction of features capable of increasing buildings robustness and resilience to deal with a wide range of elements that can impact on their operations and performances. In detail, robustness concerns the insensitivity of some parameters to uncertainty, while resilience focuses on withstanding adversity and recovering from it. These definitions can be tuned for buildings, opening the discussion on the possible strategies capable of increasing their resilience and/or robustness. Therefore, decarbonization, robustness and resilience are the main challenges of future buildings, which especially need to be addressed by existing buildings, which represent most of the stock. In this frame, the thesis focuses on the building stock of the Pantelleria Island, which represents an interesting reality to be deepened. On the one hand, Pantelleria Island, which is one of the three Italian islands selected by the Clean Energy for EU Islands Secretariat as leading islands for energy transition process, represents a key context for innovative energy interventions. On the other hand, the Pantelleria Island building stock, which is characterized by traditional and mainly historic buildings, named dammusi, must deal with existing limitations and constraints on energy interventions, making the challenges even more complex. In line with the above, the thesis aims to investigate possible retrofit solutions for the existing residential building stock of Pantelleria Island, aiming to increase both its energy efficiency and its robustness and resilience to potential future stresses. In detail, three archetypes of dammusi are defined and modelled, based on available information on Pantelleria buildings, to be representative of the entire existing stock. After analyzing their current energy needs and consumptions, alternative solutions of energy retrofit are identified, in line with the existing regulatory constraints for the protection of the historical and architectural heritage of the island. Through energy simulations, retrofit scenarios are compared, exploring their capability in reducing the environmental impact of the dammusi and in improving the dammusi robustness and resilience to future uncertainties, dependent on climate change consequences or energy supply interruptions. Scenarios results prove that the implementation of a set of retrofit solutions at building scale can provide remarkable cuts of consumptions and emissions, meeting decarbonization targets. The same retrofit solutions, however, often enhance also dammusi buildings resilience and robustness, making dammusi prepared against future uncertain and inevitable occurrences.