Can We Please Stop Drawing Trees on Top of Skyscrapers?

  • 21 Mar 2013
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Peruri 88 / MVDRV. Rendering © RSI-Studio

Tim De Chant is the senior digital editor at NOVA and editor of NOVA Next. He also writes at Per Square Mile, the blog where this article originally appeared. 

Just a couple of years ago, if you wanted to make something look trendier, you put a bird on it. Birds were everywhere. I’m not sure if Twitter was what started all the flutter, but it got so bad that Portlandia performed a skit named, you guessed it, “Put a Bird on It.” (“What a sad little tote bag. I know! I’ll put a bird on it.” Etc.)

It turns out architects have been doing the same thing, just with trees. Want to make a skyscraper look trendy and sustainable? Put a tree on it. Or better yet, dozens. Many high-concept skyscraper proposals are festooned with trees. On the rooftop, on terraces, in nooks and crannies, on absurdly large balconies. Basically anywhere horizontal and high off the ground. Now, I should be saying architects are drawing dozens, because I have yet to see one of these “green” in real life. (There’s one notable exception—BioMilano, which isn’t quite done yet.) If—and it’s a big if—any of these buildings ever get built, odds are they’ll be stripped of their foliage quicker than a developer can say “return on investment.” It’s just not realistic. I get why architects draw them on their buildings. Really, I do. But can we please stop?

Find out why it’s not a good idea to put trees on skyscrapers, after the break…

“Le Cinq” Office Tower / Neutelings Riedijk Architects, Rendering by Visualisatie A2STUDIO

There are plenty of scientific reasons why skyscrapers don’t—and probably won’t—have trees, at least not to the heights which many architects propose. Life sucks up there. For you, for me, for trees, and just about everything else except peregrine falcons. It’s hot, cold, windy, the rain lashes at you, and the snow and sleet pelt you at high velocity. Life for city trees is hard enough on the ground. I can’t imagine what it’s like at 500 feet, where nearly every climate variable is more extreme than at street level.

Wind is perhaps the most formidable force trees face at that elevation. Ever seen trees on the top of a mountain? Their trunks bow away from the prevailing winds. That may be the most visible effect, but it’s not the most challenging. Wind also interrupts the thin layer of air between a leaf and the atmosphere, known as the boundary layer. The boundary layer is tiny by human standards—it operates on a scale small enough that normally slippery gas particles behave like viscous fluids.

Pentominium / Murphy/Jahn. Image courtesy of Murphy/Jahn.

For plants, the boundary layer serves to control evapotranspiration, or the loss of gas and water through the tiny pores on a leaf’s underside, known as stomata. In calm conditions, a comfortably thick boundary layer can exist on a perfectly smooth leaf. But plants that live in hot or windy places often have adaptations to deal with the harsh conditions, including tiny hairs on their leaves that expand each leaf’s surface area and thus its boundary layer. Still, plants in these environments aren’t usually tall and graceful. In other words, not the tall trees we see in architectural drawings.

Next let’s add extreme heat and cold to the mix. Extreme cold, well, we all know what that does. It can kill a plant by turning the water inside its cells into lethal, crystalline knives. At the other end, hot conditions post a different set of challenges. To cool off, plants can “sweat” by opening their stomata to release water vapor, at least as long as there’s water available. But even then, plants reach a limit. At certain temperatures, which vary from plant to plant, the photosynthetic machinery inside a leaf starts to break down. Keep in mind these are temperatures on the surface of a leaf, not ambient air temperature. The surface of a leaf—especially in direct sunlight, as on the unshaded side of a skyscraper—can be many degrees hotter than the air, up to 14 degrees C in some species (nearly 26 degrees F).

Sky Village in Rødovre / MVRDV

Then there are the logistical concerns. How are these trees going to be watered and fertilized? Pruned? How will they be replaced? How often will they need to be replaced? As someone who grows bonsai, I can tell you that stressed plants require constant attention—daily monitoring, in fact, and sometimes even more frequently. It’s not easy. Growing simple green roofs is a chore, and those plants are chosen for their hardiness and low maintenance. Trees are generally not as well-adapted to the wide range of conditions likely to be experienced on the side of a skyscraper.

All of this may sound a bit ridiculous coming from someone like me, an advocate for more trees in urban spaces. It probably comes from having seen one too many sketches of a verdant vertical oasis but too few of them actually built. Plus, having studied plant physiology, I know that it’s a pipe dream in many ways. Trees just weren’t made for such conditions. Now if someone wants to gin up a tree that can survive on top of a skyscraper, go ahead, I guess. But I can think of far better things we should be putting our time and effort into, like preserving places that already have trees growing on them or planting more on streets that need them.

Tim De Chant is the senior digital editor at NOVA and editor of NOVA Next. He also writes at Per Square Mile, the blog where this article originally appeared. 

Cite: Tim De Chant. "Can We Please Stop Drawing Trees on Top of Skyscrapers?" 21 Mar 2013. ArchDaily. Accessed 21 Dec 2014. <http://www.archdaily.com/?p=346374>
  • i2h

    yes, thank you for pointing out this absurdity. i have, many times in the past, been asked to put trees in a skyscraper rendering. not small potted indoor trees, full oak trees. whole forests of them. in a skyscraper. in manhattan. i cringed, but did my job.

  • darren
  • j

    Love the black & white opinion of an architect!
    here is one of many overlooked example:
    http://www.mimoa.eu/images/1200_l.jpg
    http://25.media.tumblr.com/DAS9f5yCxju1785oxljzC2V0o1_500.jpg

    • Marcos Bravo

      did you read the article? these are small plant pots, not trees.

    • archilocus

      it’s neither really a tower like discussed in the article. Your example (you should name Edouard François) is about 20 to 25m high, not hundreds !

  • Ion Calugaru

    depressing..that depends on the context.. concept.. it’s not universal, you can’t say that for all the proposals.. there are some urban politics that include green roofs an spaces, of corse that depends on the context, it’s a very personal opinion..

    • Matias

      He’s talking about trees, not green roofs.

  • Anthony Willats

    Couldn’t agree more … it’s ridiculous imagery. But take a look at the Torre Guinigi in Lucca … a group of Holm oaks atop a medieval tower! Fabulous!

  • TMNL

    Good to finally have this point tackled. In every design competition nowadays trees appears to be the key selling point in a mediocre design.
    The way trees are photoshopped last minute on top of buildings (who needs to consider roots on a presentation image, right?) borders the absurd. Just like every rendered city square is crawling with kids with baloons and ice cream vendors. It is just used for packaging something that lacks quality without and rarely survives sketch phase.
    And because it appears to work commercially -everybody is doing it- it is turning greenness into the empty fad it should not be. Architects thinking they have to follow the masses, not to loose in advance. And more and more of these images appear.

    As you indicated using trees in architecture like in those images is virtually impossible in real life. This is because of characteristics of the greenery itself, the lack of knowledge most professionals have in this field, and finally (and mostly) the extensive costs and care it needs afterwards.
    Curious about designing roof gardens I have been searching for academic publications a few years ago. It became clear to me how little knowledge there is available on the practice of using green on buildings, other than the standard industrialized solutions. It was simply too much of a risk to even propose such a thing.

    I love reading books like Ken Yeang’s, and dreaming about this stuff. But at this moment 95% of the images I find online belong in the fantasy category, not architecture.

  • mahler76

    thank the Gods, someone said it about these hipster ideads we are seeing tha last years.

  • Wyatt

    Yes, this trend of re-creating landscape on the sides and surfaces of skyscrapers isn’t new, and without purpose it is simply decorative.
    However, there are many reason to use and incorporate landscape into architecture, and there are tree/plant species that survive and thrive at high altitude. It is obvious that delicate vegetation should not be thrown on top of our cities, but the harsh growing conditions on mountain tops still promote plant life and diversity. Although it is a different aesthetic than shown in the above renderings, the raw characteristics of nature in harsh climates might be a little more interesting anyways.
    When we begin construction, we are scraping away land that over time developed on its own to mediate the surrounding environmental conditions. Without the indigenous species there to maintain that balance, the built environment becomes an unhealthy and disruptive place to live. The footprint (+) of buildings needs to be intelligently given back to the ecology at some point along its construction.
    It is also proven that seeing a tree out the window, as opposed to another built surface, alleviates stress and anxiety (pressures of society), and being in a landscaped environment has shown to chemically improve the immune system, fighting disease and viruses.
    It is not only important to maintain the ecological balance that was once set up, but for the health and mindset of people, access to landscape, even visually, is a necessity.

  • Matias

    Great post. The concept visualization industry that has emerged from architecture needs to look in the mirror and cut the BS. The images are beautiful and I’m a huge fan of rendering, post production, and these amazing firms that are better at it than I am. But lets be real here, we could render a cube in a trash dump and make it look like a million bucks.

    Its the renders I tell ya! They’ll get us all!

    • i2h

      yea, it must the visualization industry, not the clients or architects requesting these things. very astute observation.

      • Matias

        Are they requesting the trees on the buildings or are they requesting trees in the render? The render still creates a false sense of realism. Like you said yourself, you cringed, but still did your job. Even buildings that dont have trees on 40 cm slabs, that are rendered beautifully, have zero sense of context and look terrible in real life, but the client is amazed. As the concept render for an idea its fine to do as you please to convey a message, but as a presentation image for a client I’d say the opposite.

      • i2h

        you seem to be under the assumption visualizers wake up in the morning telling themselves “today, i’m going to put some 30′ elms on a 1.5′ slab.” no, believe it or not visualizers do have common sense, and a good many prefer realistic (to a degree) representations over fanciful imaginations. i would venture a guess a number of the presented images above were in fact done by the architects themselves. the more polished ones with the offending trees were likely requested to have “nice full trees” or whatnot…usually admitting it’s more for effect rather than reality. so to your original post, you’re asking the wrong people to “look in a mirror”. as for the bs…you smelt it, you dealt it.

  • Henrique Vicente

    I see you have a good point…

    What about just building taller buildings with trees on the vicinity? I find it a more realistic win-win scenario.

  • Chris

    There is a great deal of truth to this.

    I can’t help but notice that this is on ArchDaily, which was a cheerleader for the whole trees-on-buildings rubbish.

  • jupp

    FINALLY!!! someone had to say that.

  • Farid Apandi
    • mindgame

      Oh god, i wish that man never existed.

      • illuminatus

        at least le corb sketched and practiced in the ground…he could make the connections much better than any of us…not sitting on our laptops and rendering in PS

  • Sam

    I often wondered about those trees planted on 40cm slabs…

  • gbot

    Trees on Buildings are not something new. And can often be quite a nice addition.

    http://activerain.com/blogsview/3149723/vancouver-secrets-2-that-famous-building-with-the-tree-

  • eduardo NL

    people seriously, who is this guy. it’s a design concept, it is a utopian way of thinking of (all) architects. for those who know the history of architecture, in 1909 a group of people began with the movement of Futurism Manifesto. the architect Antonio Sant’Elia (La Città Nuova by Sant’Elia, 1914)translated the futurist vision into an urban form, that later motivated other architectural movements (art deco). In this time architects were able to design airports at the top of the buildings. So, it’s not about if this is not possible or not, but it is a belief for the future. I think you should bring better arguments to defend your thesis.

    • TMNL

      @ eduardo NL. I think your issue is a different one than the author tries to cover. The problem here is that utopian imagery has crossed over into renderings of real life projects. The images shown in this article are real proposals that should be built in a few years and none of them can be technically executed as displayed, because trees don’t do so well on 15 cm substrate in the windy conditions at 50m or higher.

      There is nothing wrong with dreaming, and I don’t see this as an attack of Callebaut-like conceptual images but as an attack of designers who lie to their customers by dressing up their concepts with ideas that cannot be executed.

    • Devin Way

      What is the point of a Utopian design if we never strive to achieve it? Some of these designs are complete bs where they Photoshop in some trees at the end. It is most definitely about the posibility or not, about achieving these ambitious goals we set for ourselves. And we should not and cannot simply wait for a designer in the future to accomplish this feat. Like TMNL says “there is nothing wrong with dreaming”. But I do find it a failure to keep these innate desires to remain a dream and nothing more. The issue mentioned is that these are buildings with a few green spaces sprinkled on the surface. What we need, and what is starting to gain some footing, is the incorporation of these park spaces throughout the entire design of projects, rather than just an after thought to sell the building.

  • kepawi

    thinking such as this is why we don’t have trees on buildings.

  • NorwegianSoul

    Curious that you suggest it is not feasible to put trees on highrises. Here is an example in Vancouver, BC (Canada) which has existed very successfully for years! http://www.flickr.com/photos/irene3/3062610399/

  • JAAAAAAAT

    While agree that green-washing-photoshoping is lame,it is not entirely impossible.
    tree roots grow laterally, not down. so they just need some space. like a roof. Also your mountain argument is ridiculous. Trees grow in the most inhospitable places. in/through solid rock, on cliff etc.
    also, http://behnisch.com/projects/135

  • NorwegianSoul7

    It is curious that there is so much skepticism about the idea of planting trees on a highrise, when a successful example has existed for years in Vancouver, BC (Canada).

  • Andrew

    If Trump can have trees on Trump Tower in Manhattan, why can’t everyone?

  • JP

    Boo.

  • archi

    Yes, because a 10m high tree can grow in 200mm of dirt. Always has. How do we greenwash this? Stick some trees on there to get the job. Worry about the realism later. Dilbert’s manager would be proud. No wonder architecture is the laughing stock of the professions.

  • Radoslav

    I have not yet seen an architecture office considering trees in their design, without fully understanding the needs such a design descision carries. Creating a phantasy CG with jungles over rooftops an architecture student in his first year may produce, shouldn’t in any case be considered architecture. While planing such an effort, I asure you, since I do have experience in that field, brings a variety of experts to the table, one of which is surely a professional in that field of expertise, considering can a tree and which tree grow in that height, as well as which dimensions are necessary for it to thrive.

    • Martin Cosentino

      The Hanging Gardens of Babylon were considered one of the Seven Wonders of the World, and there is not a SINGLE reason why our cities cannot be turned into urban forests- again!!!! A 40 story residential apartment building with 20,000 sq ft of roof area available turned it into a vegetable and plant producing garden that saved thousands of dollars monthly on cooling costs, preserved the roofing materials from UV radiation, and produced enough food for 200 people, large plants and small trees for the interiors. Look at the ‘boscos verticales’ going up in Milan, Italy to get some idea of how this green movement is taking ‘root’[pun intended]. Anyone here who thinks putting growing green things on top of buildings is foolish or naive, is just not paying attention to what is happening all over the planet. I would say ‘get with the program’ if you believe in sustainability.

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  • Reverend Juan

    I agree that the use of trees in tall buildings appears to be a current trend. As with any trend, I feel as a design professional that I should be wary of the result and the implications of blindly following along. However, I disagree with the notion that it is technically flawed, or necessarily difficult to include trees, even large trees on a tall building. Tree restraining, adequate soil depth, appropriate roof waterproofing/insulation, irrigation, and appropriate species selection are well within the realm of what we as design professionals can specify and ‘control’. There are numerous examples of high trees on tall buildings; if done correctly trees on a roof can be integrated beautifully. I do continue to be sympathetic to the author’s concern that the trend is alarming; but I hesitate to identify the technical constraints as the issue. Corbusier codified the roof garden, a modernist motif that is worthy of consideration in any project without fear (in my mind) of appearing trendy. The author hits on the real trend which is that the “tree” becomes a stand-in for a thorough understanding of how to integrate a sustainable approach to design, and ‘the giant trees’ effectively illustrate the elusive struggle to create ‘heroic architecture’ that in some cases is devoid of a deeper meaning or concept.

  • Louise

    I live in Singapore and we have plenty of trees on skyscrapers here. I’m not saying they all survive, but those which are designed right do just fine. I’m also not sure they add anything to the environmental credentials of a building (all that extra concrete to hold them up…) but at least they help the ‘greening’ of this concrete jungle.

    • Hong My

      I think this problems also needs to concern more about climatic characteristic of places. I agree that the tree can live quite well on skyscrapers in Singapore because of the calm and warm climate here throughout the year, I live there in two weeks and I had not experienced strong wind, even normal wind here. But in Vietnam, the wind could be a severe problem. I think the answer for this argument is every design needs careful investigation before proposing anything.

  • guillermo

    have you seen marina bay sands building in singapore ?

  • Apoorva

    Thank you for this article. I often see such skyscrapers with absurd amount of trees and even zoos of animals living and thriving. Architects almost make you feel like the have recreated amazon and harmonious human living. And many dumb ass juries select these absurd ideas. We are more into the render and image rather than the idea. Many are creating avatar like hocus pocus stuff and we ooh and aah those ideas. We need to create sustainable new ideas even if that means no skyscrapers at all.

  • archilocus

    I would extend the author’s thought to balconies on high rise buildings, for the same reasons as he mentioned for trees : high speed winds, cold, etc…
    Anybody who have stand on the top of a building at about 50m high cannot seriously plan balconies anymore at heights you most of the time don’t even have the possibility to open windows due to depression.