Performance of Green Roofs in the Mediterranean Region: A Numerical Study Based on Energy Balance

¹ University of Genoa - Department of Mechanical, Energy, Management, and Transportation Engineering, Genoa, Italy
² University of Cyprus - Environmental Fluid Mechanics Laboratory, Department of Civil and Environmental Engineering, Kallipoleos Ave, Nicosia 1678, 20537, Nicosia, Cyprus

^* Corresponding author: augusto.bocanegra@unige.it

Abstract

As urban areas seek sustainable solutions to address the effects of climate change, green roofs have emerged as a promising strategy for improving building energy efficiency and enhancing urban resilience. This study evaluates green roofs' thermal and energy performance in the Mediterranean context through numerical simulations of a standard office test cell, modelled using EnergyPlus. Two cities with different climatic locations, Genoa (Italy) and Larnaca (Cyprus), were studied. Key parameters examined include soil thickness, vegetation type, plant height, and Leaf Area Index (LAI). The results demonstrate that green roofs can reduce annual energy demand by up to 18%, with performance strongly influenced by local climate and baseline roof insulation. In Genoa, green roofs primarily reduce cooling loads, while in Larnaca, the dominant effect is on heating demand. The energy-saving potential diminishes in buildings with higher baseline insulation. These findings offer guidance for optimizing green roof configurations tailored to Mediterranean climates and support their integration into sustainable urban design strategies.