Planning and selection of green roofs in large urban areas. Application to Madrid metropolitan area

•New methodology is presented to select the best location of green roofs in large cities.•This methodology helps to determine the most suitable neighborhoods, analyzing four main variables of interest in urban environs.•LIDAR data helps to identify available roofs for the installation of the green roofs according to the height and roof typology of the buildings.•To select the optimal roofs, connectivity analysis techniques are needed.•This methodology helps to improve the connectivity of the green spaces of urban areas, promoting sustainable and quality urban development.