On the localised climate change mitigation potential of building facades

Within the bounds of climate change, the design of public spaces and buildings must contribute to the local thermal mitigation. In this context, there has been a considerable body of research emphasis on reducing the Urban Heat Island (UHI) phenomenon via the resurfacing of public spaces, streets and roofs, with vegetation and cool materials. At the time of writing, minor attention has been given to how buildings' façades could affect outdoor temperature ranges. Whereas facades are studied according to their capabilities of reducing building energy demand and grant indoor comfort, but scarce attention has been given to how their surfaces properties are affecting local microclimates. The proposed work thus assesses the thermal mitigation potential of façades properties such as windows to wall ratios and finishes attribute, such as reflectivity and emissivity. The study, starting from the definition and calibration of a Ladybug Tools' simulation workflow for the assessment of outdoor comfort conditions, simulates urban canyons located in three climate types (temperate warm, temperate cold, and tropical arid), parametrises façade types, along with canyon aspect ratios and ground thermal properties. By creating a hierarchy of importance of interventions between aspect ratios, ground and façade finishes, the work offers information useful to foster site-specific climate mitigation plans.