The highest
frequencies shown in the histograms of Figs. 1e3,6 and 8 indicate the most probable values of the personal NPV. Hence, the most probable benefits for extensive green roofs are $291/m2, $21/m2 and $400/m2 for personal, social, and personal and social scenarios respectively. For the case of C&D waste based green roofs is $291/m2.