Traditional and Bioclimatic Design for the Energy Retrofit of Existing Buildings

The energy renovation of the construction sector encompasses social, economic, and environmental sustainability. Energy-efficient buildings not only involve a reduction of energy demand,
$\text{CO}_{2-\text{eq}}$
emissions, and operational costs but also improve occupant comfort. The EU challenge of climate neutrality by 2050 requires a great effort in the construction industry, especially regarding the existing built environment. Traditional energy-retrofit approaches might not be suitable to face climate change, and this has attracted interest in designing and testing bioclimatic strategies. This study investigates the potential of innovative and adaptive measures - opaque ventilated facade, double skin facade, movable insulation, and green roof - as an alternative to the traditional ones - thermal insulation, efficient window components. The analysis is carried out for a Mediterranean non-residential building, examining energy demand in both seasons. All technologies show good behavior in the heating season, and if the whole envelope is energetically renewed a saving of about 95% is achieved with both approaches. In the cooling season, however, the bioclimatic interventions determine a reduction of about 16% in the energy demand compared to the 3% achieved with traditional measures. Comparing the strengths and weaknesses of both approaches, the study aims to identify the most effective strategies to support the decarbonization of existing buildings and mitigate urban overheating.