In the last few years, ‘the lungs’ of cities (parks) have been getting an increasing number of ‘fellow fighters’ for healthier urban environments. The 21st century cities have already joined the green story, with more and more architectural projects that incorporate green roofs and vertical gardens.
Green houses are nothing new, actually. The traditional Scandinavian houses (a fairytale-like, just like the hobit’s house from the Lord of the Rings) testify to this. However, the novelty is the very idea of using nature (in the shape of green roofs and vertical gardens) in urban environments which is an ideal construction planning format for future cities.
Green roof, or the so-called “fifth facade”, is actually a roof structure covered in vegetation. Depending on the type of vegetation, they could be:
- Extensive
with the vegetation of up to 20cm in height and depth of soil of up to 10cm. These are the easiest to maintain because these plants are resistant to sun and drought periods, and they are also not too heavy for the roof.
- Semi-Intensive
with the vegetation of up to one metre in height (seasonal and perennial plants).
- Intensive
They almost resemble real gardens. They are the most demanding in terms of maintenance, and require additional construction and a slope for water drainage.
Advantages of green roofs
Besides contributing to special aesthetics, green roofs are also a good investment in the energy efficiency of the building.
These are some of the benefits:
- in winter they provide heat, in summer they have a cooling effect
- provide ideal sound insulation (reduce noise levels ranging from 40 to 60 dB)
- contribute to the improvement of microclimate in urban environments (air filters)
- mitigate the effects of the so-called heat islands
- contribute to reducing smog, pollutants and dust in urban areas
- save money in terms of energy spent by cooling and heating devices
- ideal green relaxation areas
- enhance the appearance of cities and make them look decorative.
Urban gardening
When we talk about green roofs, it is almost impossible not to mention green facades.
The trend of vertical gardens is becoming increasingly present in the world and in our country – the meticulously planned green installations are being increasingly used in on the city facades. These green installations break down the monotony and elevate landscape architecture to a new level, plus they have a positive effect on the environment (air filters).
Lately, vertical gardens have been moved from the exterior to the interior, so terrace gardens began inhabiting homes and now live on inside walls. They do not take up too much space, while, on the other hand, and depending what plants are used, they also act as air purifiers (ivy, palm, aloe vera, ficus, fern), or cooking herbs (rosemary, thyme, mint).
There are projects like Vertical Forest City, which is the brainchild of the architect Stefano Boeri who designed the entire building complex covered in vegetation in the Chinese city of Liuzhou with the goal of fighting pollution in this city. The same architect has devised many other similar projects inlcuding Bosco Verticale (Vertical Forest), a building in Milan which teracces are covered in plants and trees in order to reduce carbon-dioxide pollution.
In order to maintain the idea of healthy, living, sustainable cities, green roofs and vertical gardens are an indispensable detail for architects and urban planners. These green oases in modern cities are actually their future.