Green and cool roofs’ urban heat island mitigation potential in European climates for office buildings under free floating conditions.

Highlights: [•] Green and cool roofs are studied versus their urban heat mitigation potential. [•] Insulation level and thermal mass of cool roofs are examined. [•] Irrigation rate and vegetation type of green roofs are analyzed. [•] Free floating conditions for various climatic regions are used. [Copyright &y& Elsevier]