Microclimate mitigation for enhancing energy and environmental performance of Near Zero Energy Settlements in Italy

This work aims at shifting the focus from single-building to the inter-building scale in construction settlements design by proposing a multi-scale approach, coupling outdoor microclimate mitigation and building energy prediction and saving. The developed procedure links (i) the assessment of outdoor microclimate and mitigation techniques for counteracting Urban Heat Island, (ii) Near Zero Energy (NZE) Building energy efficiency design and (iii) the minimization of their environmental impact in terms of CO2eq. In this view, a multi-objective analysis is carried out by investigating the most proper inter-building size to be focused on for sustainable cities, able to optimize these three targets. Both the energy and environmental aspects are considered at different urban scales, starting with a single-building analysis and progressively extending the field of action. The presented methodology is applied to a real new residential NZE Settlement in Italy. Findings show that microclimate mitigation strategies, e.g. increased vegetated areas and highly-reflective envelope materials and permeable pavements, can lead to annual energy saving up to 12 % and reduction of summer operational CO2 emissions by 4 % at building level. Such benefits reach about 22 % energy savings and 5 % operational CO2 reduction when extending the size of the mitigated area to the whole settlement.