Urban gardens: green roofs, vertical gardens and vertical forests

The most recent record of 8 billion inhabitants on Earth reminds us of historical population growth levels, the mobilization of the population towards urban centres and, consequently, the alarming signs of disruption of the environment and resources. On the other hand, we see a growing concern of the population with the environment, the space where they live and work, the future of the planet, and a greater ecological and social awareness of all.

In recent decades, new construction and architecture techniques have emerged that will increasingly influence “green constructions”, which include green roofs, gardens, and vertical forests. Discover, in this article, the differences between them, the advantages of including these solutions in buildings and their importance for creating greener and more comfortable urban environments.


Natural tapestry


Planting on roofs, terraces, balconies, and walls is one of the latest trends that connect the worlds of agronomy, architecture, engineering, urbanism and biodiversity.

Anyone who believes that this trend is very recent is wrong! Today, with the deficit of green spaces, the reduction of biodiversity and the marked impermeability of soils, green roofs bring immense advantages and are part of many projects. However, in the 20th century, although there was already an appreciation of green spaces, its purpose was different. In 1903, in Paris, an apartment block with terraces and gardens was built, in 1914, in Chicago, Frank Lloyd Wright designed a restaurant with a roof garden, and Walter Gropius idealized a similar project in Cologne. It is these projects that restart this trend, even if only with an ornamental purpose. The famous architect Le Corbusier is credited with being the first to use green roofs from the 1920s onwards systematically, but only within the context of building for the elite.

Today, green “surfaces” are a trend across Europe and have become veritable “natural tapestries” that cover urban centres. Many countries and cities already have incentive or mandatory models for their applications. For example, Basel, Switzerland, has the world’s largest green roof area per capita, thanks to government incentive programs; in Stuttgart, Germany, about a quarter of all flat roofs are green, and in London, 1.3 million m² of roofs have green roofs.


Walls, terraces and green roofs: a trend in Sustainable Architecture


The vertical garden is the layer that unites nature, architecture and construction. For its implementation, it is necessary to install vegetation of different species, either through a support that keeps them distributed over a vertical surface or through green walls, achieved using climbing plants and traditional gardening. Vertical gardens can be used on facades or interior walls and give a biophilic design to places by favouring environments in aesthetic and environmental terms, namely by retaining harmful particles such as CO2. In addition, they promote their users’ well-being through the connection between nature and people, improve air quality and break the grey monotony of urban centres.


Covent Garden – London


Green roofs, also called landscaped roofs, living roofs or green roofs, have gained more and more space in real estate projects and are an installation of vegetation planted over a waterproofing system that is installed on top of a roof of a built structure. Landscaped roofs can also be classified by their typology as: extensive, semi-intensive or intensive, depending on the depth of the substrate, irrigation needs, accessibility to the public and types of maintenance.


Main advantages of these systems:


  • Contribution to improving air quality;
  • Increased biodiversity, as they can be undisturbed habitats for plants, birds and insects;
  • Maintenance of rainwater;
  • Mitigation of the heat island effect in large cities, lowering the temperature;
  • Promotion of the well-being and quality of life of the population;
  • When designed for recreational and leisure spaces, they can become real recreational places in urbanized areas;
  • Enhancement of aesthetics and landscaping;
  • Agricultural development in urban areas, as roofs provide an opportunity for the production of vegetables and other horticultural crops;
  • Improvement of energy efficiency, namely by reducing the thermal amplitude;
  • Increased durability of insulating materials.


Green Roofs
8 House designed by Bjarke Ingles Group (BIG) – Copenhagen


Finally, we must also highlight the Vertical Forest or Forest, a green covering that develops by “landings”, that is, buildings with structures/platforms designed to insert a layer of vegetation on the facades. A harmonious fusion between architecture and nature brings a greener and more natural landscape to the urban fabric and a set of advantages as vast as those listed above. Developed, as a rule, from the insertion of trees of different sizes and sizes, shrubs and other species of perennial plants, they create veritable green curtains that change according to the seasons, as occurs in nature.


Coberturas ajardinadas
Bosco Verticale designed by Stefano Boeri Architetti – Milan


At this moment, it is already noticeable that the pandemic situation has profoundly changed the paradigms of architecture and construction, namely in sectors such as residential and offices. One of these changes is the investment in green areas, contemplated for buildings, which take shape through the possibilities we have seen throughout this article. In this way, adopting these systems brings with it a set of indisputable advantages that also respond to the environmental concerns of the various players in the market, helping, for example, to obtain reference certifications such as LEED (Leadership in Energy and Environmental Design).

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