On November 11, the auditorium of Lavis (Trentino, Italy) housed a conference on possible solutions to reduce the environmental impact of urban buildings, including green rooftops.
The initiative was organized in two sections. The first was mainly dedicated to urban greening experts and consisted of a technical lecture by Helga Salchegger of the Laimburg Research Center . Salchegger described the steps for constructing green rooftops and explained which structural and static factors must be considered, which types of green roofs are already applied (extensive and intensive), and what benefits they bring. They are beneficial both for rainwater retention and building insulation (thermal and acoustic), but particularly for environmental purposes. The latest ongoing studies aim to set up green roofs that maximize biodiversity, mixing internsive and extensive roof greening methods, adding taller plants, boulders, non-vegetated areas, gravel knolls (where wild bees can nest) and logs (which provide food and shelter for various insects). The studies have shown that for many species, green rooftops can be an undisturbed oasis in the concrete ocean of highly urbanized cities.
In the second conference section, open to the whole community, Eurac researchers Silvia Croce and Sonja Gantioler presented their study on the possibility to increase the total urban green surface by exploiting the rooftops in Bolzano South : a “concrete-sealed” industrial district of the size of approximately one third of the city. The two researchers first described the main problem in highly urbanized areas: the temperature rise caused by both the heat absorption (and return) of artificial surfaces, and poor ventilation in dense build-up areas. This can then generate the so-called heat islands.
In areas affected by heat island effect, the average temperature can be up to 1 °C higher than the average temperature in the surrouning areas.