Technology Transfer Department

Application sectors

Problem to solve

The assessment of the effects of green building envelope technologies, such as green roofs and walls, can be carried out using modeling and simulation software that requires: 1. a large amount of input information; 2. long computation times; 3. powerful computers; 4. specific and in-depth expertise. These requirements are often not met by municipal offices responsible for drawing up urban heat (an unintended increase in temperature within cities due to urbanization) island adaptation plans. Furthermore, urban heat island adaptation plans are often costly, and their effectiveness must therefore be assessed ex-ante. However, commercially available software does not facilitate the task of those who have to develop and evaluate such plans. The synthetic methodology developed is able to predict with good accuracy and without specific expertise the adaptation potential of plans based on the application of green roofs, green facades, or living walls.

Description

The proposed methodology is based on regression models fed by the results of approximately 300 ENVI-met simulations. For these simulations, over 250 adaptation scenarios were created, starting from the baseline scenario consistent with the status quo of three urban areas in three cities with a Mediterranean climate. The urban heat island adaptation values as the adaptation scenarios varied, i.e., the change in air temperature at pedestrian height compared to the baseline scenarios, were used to feed multiple regression models from which three equations were extracted (one for adaptation plans based on the installation of green roofs, one for adaptation plans based on the installation of green facades, and one for adaptation plans based on the installation of living walls). These equations are based on three fundamental parameters for urban heat island adaptation: building height, percentage of surface area covered by green envelope technologies (green roofs or walls), and leaf area index. Compared to commercially available microclimate software, the equations developed require a very limited number of inputs. The outputs of the equations, i.e., the median variations in air temperature at pedestrian height, or the potential for adaptation to the urban heat island, were tested and compared with those of the microclimate simulations. This comparison showed that the equations developed are characterized by an error ranging from 0.04 °C to 0.05 °C.

Research group involved