Architects love to be able to design and build an iconic tower. And a city counselor can leave his signature with it. Well, it happens that the world is urbanizing, and that we see a lot of high-rises in planning, framed as ’there is no other way’: we have to go up. And everyone kicks in, and we all like the pictures. But it is not a good idea, and there is no reason whatsoever to build high rises. As follows:
1 There is a delusion that high density can only be achieved with high-rise buildings. But that is proven nonsense, one of the most densely built-up cities in the world is the Parisian city center, almost entirely consisting of 5 or 6 layers and generally recognized as a city with high architectural quality (on average 21000 inh/km2). In most Parisian districts, the density is higher than that of, for example, Manhattan (26000) . And take Dhaka, the most densely populated city in the world, is a relatively low-rise city.
The most densely populated km2’s in Europe, even nearly twice as much as in the Parisian city center, is found in Barcelona, the Eixample district, with 35,000 inhabitants/km2 ! Recognized as a highly appreciated urban expansion, some 6 storeys high. Cities with a lot of high-rise buildings have a usually a lower density. And where the density does exceed that of Paris, it is often unlivable.
1b And low-rise building is generally regarded at the expense of land? But all the inhabitants of the world together in the density of the center of Paris fit on an area of approximately 400,000 km2, or not even 2/3 of France …. * (Not that we should to do that, is not convenient, but shows that land is not the a decisive factor in terms of low-rise cities.) ( see also picture on home page)
2 In an extensive study of cities around the world in relation to energy consumption, by colleague Serge Salat, the Parisian city center came out as the best: It is the optimum configuration with regard to sunlight , energy demand and daylight inside the houses. [1]
3 The higher a building or tower. the more energy demand per m2 floor. Not surprising, due to, among other things, all transport systems, lifts, but also pumps and the like. (and also net less floor space per storey as a result) And even the higher wind speeds at height lead to more energy loss (in our climate)
4 The more building levels on the same plot, the less the building will be able to become energy-neutral: That is, the ratio of the outer surface to the m2 floor apartment is becoming less and less, and therefore less surface to generate energy via solar panels, for example. Geothermal heat also offers no solution, because the demand on that small piece of land is much too large to use a form of geothermal heat on the building plot. Arup came to a study 10 years ago that a skyscraper could provide only up to 10 pct of its own energy . [2]
5 The higher a building, the more shade it will cast on neighboring buildings, and thus deprive them of their ability to generate renewable energy themselves. And that’s what we strive for. Again, think of the Parisian downtown configuration. [3]
6 The height also increases the amount of materials per m2 of realized floor surface: An average apartment complex of 4 layers will weight around approx. 1000 kg / m2. This will increases slowly with height, up to 2000 and more for real skyscrapers. (even up to 3500 kg / m2 for the Malmo tower of Calatrava, ‘only’ 100 meters high) [4] This creates a 2 to 3.5 times higher material load per m2 floor, with accelerated materials exhaustion, and on average 2 to 3.5 x more energy for producing of the materials (embodied energy) for the same m2 floor. That does not help in achieving CO2 reduction. (In low-rise buildings in wood or straw-bale loam construction it can sometimes even go back to 5 to 600 kg / m2.)
7 High-rise buildings increases traffic pressure and thus forms an enormous point load in the infrastructure. Which on the one hand leads to a high environmental impact of the building due to the addition of, for example, a parking garage, but also to an attack on the functioning of city traffic: and those costs are passed on to society, that has to create solutions like metro stations, traffic junctions and the like.
8 Towers are in fact dead-end streets, for which elevators are necessary, and where people pass each other anonymously. Social cohesion is thus disturbed. [5]
9 Because they are a dead end streets, people are trapped like rats during calamities. There is no backdoor. Compare it to mega stables in livestock farming, if a fire breaks out, huge numbers die. And security measures again cost a lot of energy and material. Or requires special equipment for the fire brigade, costs passed on to the community.
10 High-rise buildings are the opposite of what is referred to as resilient cities . The moment there are problems in the local or global distribution systems, of water, electricity, food, on which people in a tower are 100% dependent, there is no saving in it: If the power goes out, people get stuck. People in towers have no possibility of becoming self-reliant in terms of water, energy, food or material (and think of Belgium that has already announced major blackouts). How does a city with all high-rise buildings take care of its citizens if they are all trapped in those towers, without water or electricity or food? [6]
11 High-rise building is nothing more than stacking people to get more financial benefit from a m2 of land that is in private ownership. It is a financially driven process that has nothing to do with urban planning and optimization. And the more land owned by a few, the higher the price can be driven up and therefore the higher the high-rise.
In short, can anyone mention benefits to me apart from the view? (If there are no other towers around it anyway)
Oh yes, I nearly forgot, the newest thing that architects (or project developers) have come up with is, in an attempt to continue to build high-rise buildings, then just put trees on it. Giving the municipality an excuse: look at how green we are. The clothes of the emperor, and of course the biggest nonsense. It should suggest that the building is sustainable, or green, or healthy. Well, in the first place, see above, high-rise is no solution anyway. But because of all the green added it even gets worse. The buildings weight increases to support those trees, balconies are enlarged and strengthened. Causing more material input, and energy and fine dust in production of those materials. More then the tree can compensate, probably. But most importantly, that tree deprives the building of the possibility of generating something of its own energy needs. The entire facade is shaded. [7]
With the invention of the automated elevator, by Otis in 1862, the misery started. I therefore classify the building history as BE and WE: Before Elevator and With Elevators. And so, given the above arguments, I would like to argue for an elevator-free environment, the era of AE, After Elevator. Maximum 5 to 6 layers, socially mixed inhabited, and all about the same height to optimize the use of (solar) energy.
References:
[1] Salat Serge, 2007 Energy and ecology efficiency of urban morphologies: a comparative analyses of Asian, American and European cities, 2007, Hong Kong SB07 Conference, 2007, Post conference book proceedings: ISBN: 978-988-17808-1-2
Also: Cities and Forms: On Sustainable Urbanism, Serge Salat, 2012, 543 pages, ISBN-13: 978-2705681111
[2] See my paper and references on reserachgate for the 2007 UIA Conference: How Tall is a sustainable building? Paper for the XXIII UIA World Congress of Architects, Torino, Italy 2008
Session HOPE, July 2, 1330,
[3] article: http://www.ronaldrovers.com/right-for-sun-a-guaranteed-free-solar-access-window/
[4] Rovers R. 2010 Material-Neutral Building: Closed Cycle Accounting for Buildings Construction A new practical way to measure improvements in creating a balanced resource use for construction
Journal: International Journal of Sustainable Building Technology and Urban Development Volume 1, Issue 2, December 2010, pages 152-159
[5] http://www.ronaldrovers.com/the-elevator-a-dead-end-road/
[6] column for EU Smart Cities information platform: https://www.smartcities-infosystem.eu/newsroom/blog/creating-truly-smart-cities-plan
