Building Facades for Climate Adaption. An Experimental Integrated Method for Indoor and Outdoor Evaluations of Energy Building Envelope Retrofitting

The urgent need for cities and urban areas to increase climate adaptation efforts, requires new approaches and more integrated strategies. To address the Climate Change (CC), the energy retrofitting of buildings needs to be more aware of the correlations among outdoor and indoor. The buildings and the building envelopes play a double role, influencing the energy consumption, the greenhouse gas emissions, and the thermal outdoor conditions. The energy retrofitting of existing buildings is still an essential element of climate adaptation. Evaluating building envelope retrofit solutions at the same time in relation to indoor and outdoor effects will be increasingly important in near future. This study proposes a novel methodology for building envelope retrofitting, integrating evaluations for both indoor and outdoor with the aim to highlight the relationships between building performances and outdoor microclimate. The proposed method is based on a cohesive sequence of activities, analysis and simulations, focused in particular on opaque facades. It starts from the definition of a reference scenario, as current status, including architectural and technological inquiry, climate data and a common 3D model. A set of energy metrics is selected: Universal Thermal Comfort Index (UTCI) and Mean Radiant Temperature (MRT) about outdoor and CO2 emissions and Overall Heating Transfer Coefficient (H’T) about indoor. Simulations for each metric are performed and replied for the intervention scenarios, using energy parametric design tools. As an applicative case study, an urban residential block, in San Benedetto del Tronto, a coastal city in central Italy is chosen.. Two non-invasive intervention scenarios on opaque facades have been tested. By means of the methodology application, comparisons of different interventions can be directly evaluated in relation to their effects on indoor and outdoor. Results side by side from analysis and simulations on outdoor microclimate and indoor energy performances can support the decision process, improving energy and environmental outcomes and impacts by building envelope retrofitting. The application of the methodology by the case study show its usefulness, facilitating the identification of differences, strengths, or opposing effects among the intervention scenarios.