Among the most interesting and visible urban architectural trends that define the 21st century city are specially designed bus stops, endless tracks for cyclists to move through the heart of the city, and gardens built on the roofs and walls of buildings. In a century of insufficient space, of cities suffocated by concrete and steel, vertical and roof gardens are an ingenious architectural solution that provides a direct connection with nature, while contributing to better water filtration and temperature stabilization.
Roof gardens
As modern as the idea may seem, roof gardens are an invention of antiquity that has remained alive to this day. From the ziggurats of Mesopotamia to the rooftops of skyscrapers, roof gardens have remained an efficient and ingenious way to keep nature close in an environment where it no longer exists.
The benefits of roof gardens go far beyond the simple aesthetic and psychological effect. Through the biological processes of the plants, the temperature in these gardens rarely rises more than 4-5 degrees Celsius compared to the environment, unlike roads and buildings that store heat and can reach up to 60-70 degrees Celsius on hot days. summer (20 – 30 degrees above ambient temperature).
By keeping the roof temperature lower, gardens help lower indoor temperatures and electricity consumption. Another benefit relates to the absorption and retention of water during rains and the reduction of the volume of water that overwhelms sewer systems during heavy rains. Among the sweet-smelling flowers and ornamental shrubs, roof gardens often contain kitchen supplies. From aromatic plants to vegetables and fruits, the roof of a building can also become a welcome natural source of fresh food.
Vertical gardens
Another option where nature comes to life in the middle of concrete and metal monoliths are vertical gardens. Also known as “green walls”, vertical gardens are planted on the surface of the walls based on various systems of soil suspension and plant irrigation. Invented by Stanley Hart White in 1938, the system has become extremely popular in recent decades due to the rapid vertical expansion of cities and the growing interest in the beauty and benefits that nature brings through its presence in human communities.
The “green walls” system is based on fixing a layer of polyamide on the surface of the wall, a layer that imitates the moss present on the rocks and has the role of supporting the roots of the plants. The entire system is traversed by a network of pipes that provide water and nutrients to the plants in a closed system. The plants are carefully chosen to be able to survive in these conditions and taking into account the temperature, precipitation and wind of the area where the green wall is created.
The tallest green wall is found in Mexico, within the International Convention Center in Los Cabos and has an area of 2700 square meters. Similar to roof gardens, green walls provide a lower temperature in hot areas and periods and partial water filtration through absorption. Unlike roof gardens, green walls are more suitable for buildings in arid areas as the rate of water evaporation is lower than in the case of horizontal gardens. The aesthetic effect is at the same time incredible.