Urban spaces’ health: green and dry technologies for conservation of historic paving stones

The urbanization processes that have developed in recent years have caused profound impacts on urban spaces’ surfaces, due to careless maintenance actions and impacts of climate change. The alterations of the ancient construction solutions have limited the permeability of the historic paving stones, causing the urban heat island. The waterproof, asphalted and cemented surfaces absorb heat with a consequent decrease in evapo-breathable phenomena and modification of the natural water cycle. In fact, the infiltration capacity of surface waters decreases, the volumes and the aggressiveness of the run-off water increase. In addition, it increases the transformation of pollutants causing the phenomenon of urban smog. The use of ancient construction solutions provided dry installation systems in a logic of respect for the environment that anticipated the times. The historical reading and the awareness of the efficiency of the solution are the premise in the choice of maintenance and restoration of urban surfaces to ensure the increase of permeability. Dry solutions and green technologies, combined with the choice of suitable materials, minimizes the impact on the drainage network, in line with the concept of low impact development, returning meteoric water to the atmosphere through evaporation and improving the microclimate. The rationalization of proposed interventions can be measured by parametric assessment of environmental health.