When I look at visualizations of new architectural projects, I catch myself wondering if I don't see a green roof, terrace or balconies with lush vegetation. How? Why? Did they really forget about vertical landscaping?... It turned out that in just a decade or so, gardens in the clouds have turned into a mandatory attribute of modern architecture.
Lyudmila Beloded, landscape designer, director and founder of Beloded Landscaping bureau
Well, the city-garden was an ancient dream of mankind. Each of us knows the legend about the hanging gardens of Semiramis - but the Assyrian gardens of Amitis, according to the reconstructionists-archaeologists, had only 4-5 levels! The main difficulty in creating a blooming oasis on the terraces of the pyramidal building was the need for daily irrigation. The desert climate of Southern Mesopotamia is a veritable hell from a gardener's point of view. Pipes for supplying water were probably built into the pylons supporting the terraces, and dozens of slaves worked the mechanical Archimedes' screw for days in the summer, bringing water up from deep wells. Energy intensity is the main reason why vertical gardening remained a utopia until recently.
The 39-story puff pastry with green filling is a project of the multi-functional complex Pirelli 39 in Milan, developed jointly by Diller Scofidio & Renfro and Stefano Boeri Architetti. Image source: DS + R
Skyscrapers of the 6th century. forever changed the landscape of the cities, and in the XXI century. we have a new task - to turn these symbols of progress into sustainable ecosystems. It would seem that the way has been found - and the most famous example of successful total greening of high-rise buildings is Stefano Boera's Bosco Verticale in the Porta Nuova district of Milan. This experiment, completed 800 years ago, was considered successful - 5 trees and XNUMX thousand Shrubs planted in structural planters on the facade of the building have successfully taken root, vegetate and are a living illustration of the fact that the wildest dreams come true. In just the last few years, we have witnessed the implementation of many ambitious ideas for the integration of vegetation and architecture.
A blow to skepticism
And yet an hour before the completion of the construction of Bosco Verticale, a chorus of authoritative critics and opinion leaders called on the architects to stop drawing green towers simply because these drawings are never destined to become reality! Tim de Chant, a popular blogger, a professor of journalism at the Massachusetts Institute of Technology, proved as convincingly as possible in his articles that skyscrapers decorated with trees are nothing more than the fantasies of designers, who in this way try to mask the negative qualities of high-rises and make them forget about their harmful influence on life of citizens Why do climbers, who have conquered the height, not plant a tree on the bare summit, but install a flag on bungee cords? Merciless wind and precipitation will tear this flag literally in a month, but they will destroy the tree in a few days. "If any of these buildings are ever built, there is a high probability that the trees will lose their leaves faster than the developer can utter the phrase 'return on investment,'" wrote Tim de Chant in 2013. "The life of urban trees on the ground is enough difficult I can't imagine what it's like at an altitude of 500 feet (152 m), where almost all climatic variables are more extreme than at street level."
Bosco Verticale towers in Milan, a breakthrough project of the "chief city forester" - architect Stefano Boera. Photo source: Stefano Boeri Architetti
Would Stefano Boera's project have taken place without Arup engineers and architectural agronomist-botanist Laura Gatta? Gatti selected local plants resistant to extreme conditions, which had to withstand strong gusts of wind and make do with limited space for roots. She took into account that it was necessary to exclude allergenic plants and insisted that most trees and shrubs be deciduous - they are not only more viable, but also reduce the wind load on structures in the windiest months of the year, and in winter do not prevent sunlight from entering the apartments. Stone oaks, witch hazel, Turkish hazel, beech, plum — Gatti selected the assortment not only taking into account the height, but also depending on the direction of the world to which the facade is oriented. Thus, the southern facade of Bosco Verticale is decorated with evergreen trees and shrubs, deciduous trees are placed on the northern and western sides, and beautifully flowering plum trees and shrubs predominate on the eastern side.
Arup engineers designed cantilever terraces with built-in containers for large trees. These waterproof planters hold 5 cubic meters. m of nutrient substrate from soil, compost and volcanic drainage — lapilla. In order to prevent tall trees from falling, they are additionally secured with safety cables. Water for the irrigation system is treated technical and rainwater. At the start of the project, Stefano Boeri assumed an annual 10% rate of plant death, but as a result of all the complex solutions, it turned out to be close to zero.
The advantages of a vertical forest are sound insulation, filtration of fine dust and oxygen production, temperature reduction in the hottest months, support of biodiversity and safety of green skyscrapers for birds
Marina One Terraces, Singapore. Architecture — Ingenhoven Architects. Landscape - Gustafson Guthrie Nichol. Photo: HG Esch. Image source: archdaily.com
So, despite the strong skepticism that accompanied the Bosco Verticale project, Boeri won. He bet on the ecological advantages of the Vertical Forest - sound insulation, filtration of fine dust and oxygen production, temperature reduction in the hottest months, support of biodiversity and safety of green skyscrapers for birds (as opposed to glass towers, which kill thousands of birds). All these benefits should manifest themselves over time. But the visual qualities of a green skyscraper are already obvious to everyone. It is not by chance that Boery himself calls his towers "ecological billboards."
Who is greener?
The example of the Italian architect was followed by his famous colleagues in the workshop. French architect Jean Nouvel and landscape designer Patrick Blanc designed the One Central Park residential complex in Sydney on behalf of Frasers Property Australia and Sekisui House Australia. This multifunctional complex of two towers with a maximum height of 117 m was named one of the 50 most influential high-rise buildings built in the last 50 years.
The outside of the floating console on the 28th floor is decorated with mirrors - it is a heliostat, a trap for the sun to direct its rays to the green terraces and the courtyard-gallery between the towers. At night, the console turns into an LED screen.
One Central Park is a green skyscraper in the center of Sydney, designed by Ateliers Jean Nouvel and PTW Architects. Photo: Sardaka. Image source: wikimedia.commons
Jean Nouvel did not dare to use large-sized trees in the landscaping of One Central Park. He used about 50 different types of Australian herbaceous plants as the building material for the living walls — the 250-meter tapestries on the facade — and fast-growing vines and grapes for the green veil. The mixture, specially developed for filling flower containers, is similar to the solution for hydroponics - it contains all the necessary nutrients. Standard, box solutions were not enough - for the towers, an individual, the world's largest drip irrigation system with centralized automatic control was created. Moisture — sewage and rainwater. Fragments of the facade with plants planted in pots were tested in a wind tunnel so that engineers could accurately determine the degree of wind load on the building structure.
Landscaping not only creates aesthetic value, but also saves costs for heating and cooling and, in general, capitalizes on the object
One of the public terraces of One Central Park, Sydney, Australia. Photo: Murray Fredericks. Image source: Frasers Property and Sekisui House
One Central Park has collected dozens of different awards and received a 5-star environmental sustainability certificate of the six-star Green Star rating (the Australian equivalent of the LEED and BREAM environmental sustainability and energy efficiency rating systems). One of the important social advantages of the new building: it has many public areas where Sydney residents and tourists can walk, like in a traditional city park.
In early 2021, the American practice Diller Scofidio & Renfro won the competition for the reconstruction project of the famous Pirella Tower, the first skyscraper in Milan, built in 1958. Since then, "Big Pirella" has become morally and technically obsolete. But the current owner intends to breathe new life into this symbol of high Milan. The regeneration project worth 300 million euros provides for the creation of a green roof with a solarium on the top floor of Pirella, a transparent podium with a garden and the construction of a maximally green residential tower nearby. The new and old tower will be connected by an openwork bridge-greenhouse - it will become a specialized botanical laboratory, a branch of the Biblioteca degli Alberi (a public park in Milan, created by Piet Udolf and Peter Bless). The basis of the structure will be laminated wood, and part of the facade and roof will be covered with photovoltaic panels. Judging by project renderings, the new tower will look like a 39-story puff pastry with green filling. The vegetation of the Pirelli 39 complex will absorb 14 tons of carbon dioxide per hour. It is easy to guess that Stefano Boeri became the local partner of DS + R studio in Milan.
The Pirelli 39 greenhouse bridge is a multifunctional complex in Milan, designed jointly by Diller Scofidio & Renfro and Stefano Boeri Architetti. Image source: DS + R
People would not be people if they lost interest in progress and leadership. Therefore, despite the fact that high-rise landscaping is not an easy task, it is becoming more and more complicated. If you want to create an iconic object, stand out. For example, the NBBJ company, designers of the future Amazon HQ2 office in Arlington, plan to plant trees on the rather steep artificial slope of the Helix tower. Thus, they want to simulate a mountain forest. So that the soil does not slide down the slope, it will be covered with a coconut coating, and the trees are planned to be planted by the live staking method - by hammering lignified cuttings into the ground. Let's see what happens. If cuttings - then Helix will green up to its design image in just 10 years.
Sometimes at the will of the architect-artist, bizarre caverns, voids and wells appear in the volumes of high-rise buildings - and yes, they can also become gardens. In the 30-story building of the headquarters of the beauty corporation Amorepacific in Seoul, David Chipperfield built three empty volumes in which he placed "hanging gardens" (again a reference to the Babylonian Amitis!). These are stunningly photogenic oriental landscapes with hills and flat ponds, which reflect leaning trees, fragments of the sky and a regular grid of white metallic brise-soleil sunblocks.
The spiral shape of the Helix tower by NBBJ is dictated by Amazon's desire to prepare employees for climbing in the Appalachians. Image source: NBBJ / Amazon
Green roofs, it would seem, have already ceased to surprise and seem to be something outstanding. The cost of greening the "fifth facade" in Europe is approximately 1,3% of the total construction cost of the entire building. And the higher the building, the smaller this figure. Complex maintenance of the green roof is immediately included in the operational calculations - and here a lot depends on what type of landscaping the customer chooses - intensive (a designer landscape with the use of plants that require additional watering, shrubs and, possibly, a lawn) or extensive - a low-maintenance green carpet of grass and succulents. By the way, according to the data of the Ministry of Energy and Environment (BUE) of Hamburg, with a 40-year period of operation, the costs for an extensive green and black (bituminous) roof turned out to be comparable: 103 and 106 euros per 1 square meter. m. At the same time, landscaping not only creates aesthetic value, but also saves costs for heating and cooling and, in general, capitalizes on the object, positively affects the image of the developer and the customer.
But even in the design of green roofs, progress does not stand still. For example, the new building of the Department of Architecture and Landscape at Greenwich University not only has the largest green roofs in Great Britain, but also the most original ones. Landscape architect Allan Scott, together with the Irish studio heneghan peng architects, created a real open-air biolaboratory for the scientific department - with a self-sufficient swamp and a bioreactor made of algae. Here, students conduct experiments on growing crops using hydroponics, aquaponics, etc. — in short, they do what they would have been burned at the stake for in the Middle Ages.
High-rise garden at the headquarters of the Amorepacific company, Seoul, South Korea. Project by David Chipperfield Architects. Photo: Noshe. Image source: David Chipperfield Architects
David Chipperfield on the Amorepacific building: "Bewitched by the hanok, the architecture of which is characterized by the presence of an open courtyard, I applied ego principles to the design of the high-rise garden. Feeling close to nature and observing the change of seasons, office employees can communicate and relax in a comfortable atmosphere. Three large openings connect with the surrounding environment, opening a view of the city and mountains in the distance, forming orientation and a sense of belonging. In other words, these are windows that serve as an intermediary between the company and the city."
Why does a developer need a high-rise eco-landscape specialist?
Biofuturism is beautiful and inspiring. But do not forget that this path is thorny. And the developer can pass it without significant losses only when there is an experienced vertical landscaping consultant in his team. I am sure that very soon high-rise gardening will become a separate discipline in universities that train landscape specialists.
Each garden is a complex combination of many factors. None of the landscape architects will start designing an abstract garden in a vacuum, without carefully studying the plot, even if he has already designed a park on the next street. And even if we are talking about the creation of traditional landscapes on earth, it cannot be repeated. And even more so at the top — each project is characterized by individual conditions and features.
"Living building" is never finished. It changes over time and requires more care and attention than ordinary architecture made of concrete and glass
Qiyi City Forest Garden - skyscraper gardens in Chengdu, China. Photo source: telegraph.co.uk
Spectacular photos of Qiyi City Forest Garden, a new complex of eight 35-story towers in Chengdu, China, graced the pages of newspapers and magazines around the world in the fall of 2020. But the reason for this popularity was not the triumph, but the facap of the Chinese developer. All the apartments in the Chinese "vertical forest" were sold out at the project stage, but the new tenants are in no hurry to move into the towers wrapped in lush greenery. The problem is that mosquitoes settled in the vertical forest before people. Having put the building into operation, the developer removed himself from management, decided that now the care of balcony plants is the business of the owners. Most of these apartments were purchased as "investment" apartments, so there were very few real new residents. But insects quickly fell in love with lush thickets on balconies and terraces. In the end, of course, they were dealt with, and after measures for disinsection and pruning of overgrown plants, Qiyi City Forest Garden regained its attractive appearance. But the story itself, you must agree, is instructive.
In the humid subtropical climate of southern and central China, plants quickly take root, get most of the necessary nutrients directly from the air, and if you let them go, they behave like aggressors, capturing not only facades, but sometimes penetrating inside houses. Fast-growing vines entangle windows and doors, blocking the access of light to interior spaces. As a result, mold begins to multiply in dark rooms. And to keep this lush greenery under control, systematic, weekly pruning is necessary.
Balconies are your hidden resource
Skyscraper-gardens have been erected in China for several years in a row. Both the members of the government and the developers understand that the new residents of the new cities are people who only yesterday parted with their village houses, where their families lived for centuries. The rate of urbanization is so high that new settlers experience enormous stress. And in order to at least partially level this stress, many modern high-rise buildings in China are commissioned with green balconies and terraces. Sometimes the balconies even provide a built-in pond into which tenants can launch their koi carp.
Marina One is a multifunctional complex in the new Marina Bay Financial District of Singapore, built according to the project of Ingenhoven Architects. Landscape - Gustafson Guthrie Nichol. Photo: HG Esch. Image source: archdaily.com
Residents of Singapore, where mass migration to city towers took place in the last decades of the 85th century, are just as nostalgic as the Chinese for the pre-high-rise life in the "kampung". Today, 200% of the population of the city-state live in skyscrapers - due to the shortage of land, high-rise construction in Singapore is developing at a rapid pace. The government of Singapore has promised to increase the total area of greenery in the city to 2030 hectares by XNUMX. But since the land here is very expensive, they plan to achieve this goal through vertical gardens. To do this, the Urban Redevelopment Authority (URA) launched a program to stimulate developers, promising them preferences for projects with gardens on the roof, facades and floors. But not everyone can afford apartments in the Marina One tower, where the American landscape designer Catherine Gustafson was involved in the creation of luxurious "ziggurat" tropical gardens. Therefore, residents of Singapore enthusiastically green their balconies in standard high-rise buildings.
I am sure that very soon high-rise gardening will become a separate discipline in universities that train landscape specialists
And not only them - the pandemic forced us all to rethink the role of private open spaces. Residents of Dubai, for example, have achieved high skill in arranging balcony gardens that withstand dust storms, wind from the Arabian desert, and 50-degree heat in July and August. Because of the quarantine, the majority of residents spent last summer in their city apartments, and this provoked a real boom in microgardens - several square meters of balconies and terraces were called to be replaced by parks and resorts. This summer may be more "open", but people who once felt the joy of close daily contact with nature will look for a way to engage in gardening again and again.
Marina One is a multifunctional complex in the new Marina Bay Financial District of Singapore. Image source: archdaily.com
If we compare our climatic conditions with the conditions in Dubai, it is obvious that we are in a more favorable situation. But the design of the balcony, especially on a high-rise one, should not be taken lightly. It is necessary to adhere to several important rules:
- Remember that the higher the floor, the windier it will be on the balcony and the more "evil" the sun will be. On the upper levels of the towers, delicate flowers of violas or petunias will look shabby. Succulents — aloe, agave, echeveria, sedum, as well as plants with silvery leaves — lavender, perovskia, and sage belong to plants that tolerate wind and scorching sun rays. And, of course, cereals - today in garden centers you can find various types of hardy grasses with spectacular colored leaves that will rustle and move in the wind, giving dynamics to a tiny balcony composition. For balconies facing north and in the shade for most of the day, all kinds of hostas, geychers and ferns are suitable.
- Take into account the fact that balconies are designed for a certain load, and the structure does not always have a safety margin of an additional couple of centners of weight — and this is only four or five potted plants. Even small shrubs, such as barberry or lapchatka, already need a meter-long fertile layer of soil, and this is a solid volume and weight. You can find out the exact data on the permissible static load in your housing and operating office.
- For planting, use a light fertile substrate, not heavy, quickly stoned soil from neighboring plantings in the absence of watering. You can add loosening agents (sand, sawdust, perlite), hydrogel for moisture retention to the purchased soil, because water evaporates faster at altitude.
- Please remember that flowerpots with drainage holes should not hang over the street - when watering, water will spill from them on the heads of passers-by or neighbors. If the balcony is too narrow and it is not possible to turn the pots inside, then you should choose a planter with deep trays for water accumulation or without holes at all, increasing the drainage layer in the pots themselves.
- Remember that krupnomers (and for a balcony a plant higher than a meter is already a krupnomer) have high buoyancy, and they must be additionally secured so that a gust of wind does not blow the plant down. This is an important safety rule.
Marina One Atrium, Singapore. Architecture — Ingenhoven Architects. Landscape - Gustafson Guthrie Nichol. Photo: HG Esch. Image source: archdaily.com
"Living building" is never finished. It changes over time and requires more care and attention than ordinary architecture made of concrete and glass. Serious landscaping projects for skyscrapers are still an expensive pleasure. Experiments are always expensive, but they are all for the sake of the future. "The de-urbanization of the urban environment is a radical alternative to expensive technologies," says Boery. He spent $4,5 million on the total greening of the Milan towers. $4,5 million for the forest on the facade of the skyscraper? Yes, for these money you can create a beautiful park, much larger area. Or restore more than 500 hectares of forest! Yes, that's right. But if we want the horizons of our cities to be not a gray line, but a green one, the air to become cleaner, and we ourselves to be healthier and happier - then the game is worth the candle!
