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The green walls and future horizons

Urban greenery and its role in urban contests has been highly reevaluated in the last fifteen years, even if lack of professionalism is still widespread among districts, this year a new statute on public greenery has been enacted (410/2013).

Excellent samples. There are some regulations, much more effective than in other cities, already ongoing in several nations across europe that are keen on maintaning a better management of lands and territories and their relationship with urban construction where vegetation is one of the fundamental aspects. The following cities are some of them: Berlin (since 1980), Malmoe (since 2001), Bozen (since 2004) and Modena (since 2005). Many other cities already found some parameters to be taken as pillars to work on in order to reduce environmental impact such as permeability of the soil, energy consumption, preservation of microclimate, reduction of pollutants. On rooftop gardens, several experiences has been made on sustainability, these experiences of green performances shown us all how important are and how environmentally friendly they are being also included in some urban regulations. Vertical greenery, instead, although its presence in simplified shapes found ages ago is more recent and connected with ecological and energetic evaluations. Most of the notorious realizations, such as the famed murs vegetals of patrick blank (got loyalty in the 80’), are linked to sophisticated systems of control and management of time and energetic provision.

Green walls, necessarely development. The unstoppable research and the commercial success of green walls contribute to find new materials and methods for assembly (support panels, membranes and substrates, ferti-irrigation systems), aiming to restrain costs but keeping in mind the original blanc’s method, where total cost always range between 600 and 800 €/sqm. Obviously there are other simply and classic types of covering walls, from the traditional wall with climbing species( canadian vine, ivy and ficus) that normally adhere to the surface and other technical systems using metal supports to keep plants well ventilated, cost are kept lower than mur vegetal anyway.

Sustainability and regulation. This type of realizations are widely spreading across the world, also uni, the national institution that define standard requirements in productive sectors, issued specific regulations about green covering (uni 11235/2007). Overlooking all the characteristics of sustainability, including all the necessarily resources for the realization and maintenance (water, money, management) and comparing them with their positive and negative contributions on environmental efficiency (co2 and pollutants absorption, shading, insulation) vertical greenery doesn’t show positive results yet. Recent studies, showed us how innovation should go toward goals characterized by simplicity of realization and usage of vertical green wall, just using simple growing media with high efficiency.

Bio-concrete. A team of researchers at the polytechnic university of catalonia in spain, has developed a new multilayer concrete that is able to support plant life. Both a medium for growth and a construction material, the system allows for thermal regulation and co2 sequestration. It is characterized by low ph, rough surface, and other few characteristics that allow in around a year a fast colonization of it made by different type of microorganisms such as algae, lichens, mosses, avoiding high needs for maintenance and energy even with an overall lower performances

Coat the buildings with the vegetation is becoming an increasingly common practice. What is needed are new studies to lower maintenance costs