Evaluating user adaptation and building retrofit strategies to address overheating in a climate change scenario: a focus on energy poverty and vulnerable users

In the European Union, approximately 50 million households suffer from energy poverty, placing vulnerable groups—such as the elderly, children, pregnant women, the infirm, and people with disabilities—at increased risk of overheating, especially under climate change scenarios. This study investigates the effectiveness in the long-term of passive overheating mitigation strategies for residential buildings, focusing on those occupied by elderly individuals and children up to fifteen years old. Using a typical 1960s residential building in Milan as a case study, dynamic building energy simulations were employed to evaluate various passive cooling techniques, including natural ventilation and ceiling fans. These strategies were analyzed both pre- and post-retrofit, with the retrofit primarily enhancing building insulation. The results demonstrate that while these passive methods can lower indoor temperatures effectively, they may not suffice to maintain comfort levels in the future, suggesting the need for active cooling systems in retrofitted buildings. The study further includes a comparative analysis between baseline and retrofit scenarios, assessing the energy consumption, economic impact, and environmental benefits of the proposed strategies. The findings reveal significant improvements in energy efficiency and cost savings, alongside notable environmental advantages with the use of natural ventilation combined with fans. Additionally, this research emphasizes the importance of incorporating the resilience and adaptability of occupants through phased renovation strategies. By combining lean and deep renovation approaches, this comprehensive framework aims to tackle the challenges posed by climate change, ensuring long-term sustainability and comfort in residential buildings for energy-poor communities. As a practical outcome, the study proposes a user guide to help residents achieve thermal comfort through effective use of passive and active cooling strategies, ensuring their homes remain livable and energy-efficient in the face of evolving climate conditions.