The Effect of Urban Densification on Summer Outdoor Thermal Comfort: A Numerical Approach

Urban densification is foreseen to accommodate growing populations without expanding land use in urban areas. However, its impact on outdoor thermal comfort remains a concern, particularly in the context of climate change. This study investigates the effects of urban densification on microclimatic conditions in the Bolghera neighborhood of Trento, Italy, using the ENVI-met simulation model. Five scenarios were analyzed: past conditions (1999), the current state (2024), a future climate scenario based on RCP8.5 projections (2050), and two densification scenarios involving one additional building floor (D1) and one extra floor with façade extensions (D2). The results indicate that densification has a localized impact on thermal comfort, with temperature deviations exceeding 6°C in modified areas, while climate change exerts a more widespread influence, increasing temperatures by up to 4°C across the entire neighborhood. The findings highlight that removing urban greenery decreases pedestrian thermal comfort and that the experimented types of densifications improve thermal conditions due to the increase in shaded area. The study demonstrates the value of scenario-based analyses in supporting urban planning and provides a methodological framework for assessing densification strategies in different urban contexts.