Tag: tall buildings

• What’s with all these tower cutouts?

  

  One question that was nagging me after seeing Hong Kong’s “typical” tower typology was: what’s with the cruciform tower plan and all these notches and cutouts? Wouldn’t it be far more efficient to square off the floor plates? I figured that it had to be in response to building regulations. I was going to mention that in this post on the typical “8-units-per-floor” tower plan, but I wanted to first understand what was going on. Thankfully a reader of this blog who is from Hong Kong was kind enough to send me a wonderfully detailed email outlining some of Hong Kong’s building regulations and how they impact the design of tall buildings.

  It turns out that there are requirements for both “natural lighting and ventilation” and for “external air.” All rooms for habitation, as well as offices, bathrooms, and kitchens, are subject to these requirements. There are prescribed window areas for the “glass areas” and for the “openable areas”, both of which are a function of the room size. The glass area must equal the room area divided by 10. And the openable area must equal the room area divided by 16. I presume that these are minimum sizes because they don’t feel all that big.

  For the “external air requirement”, the room must face a street no less than 4.5m in width or it must face an unobstructed space as delineated by “rectangular horizontal planes” and by “inclined planes.” The incline planes are drawn in section from the sill of the window and the angle depends on the type of room. The rectangular horizontal planes are drawn in plan and have a minimum area of 21 square meters (or ~225 square feet). If you would like to deep dive into more of the technical details you can do that here. But suffice to say that it is these requirements which are driving all of the tower notches and cutouts.

  The result is tower floor plates that can look something like this:

  

  And if we zoom into a unit (this one being a 3 bedroom apartment), you can see that both bathrooms have a window, as does the kitchen. From what I saw, there appears to be less interest in open concept floor plans. You may also finding it interesting to note some of the room dimensions (in mm) and the A/C platform sitting outside of the master bedroom. 

  

  Finally, I should follow-up on my previous comment about tower separation distances and the ability for the above tower floor plates to be built directly adjacent to each other. Not surprisingly, this resulted in walls of towers being constructed. Ultimately this became known as the “wall effect.” So in 2011, the Sustainable Building Design (SBD) guidelines were put in place which stipulated that groups of buildings having a continuous facade length greater than 60m should comply with various separation and permeability guidelines.

  So there you have it. Every market has its local nuances. The above post is a good example of that. I also love when this blog becomes a platform for two-way discussion. I learned something new today and hopefully you did too. Thank you Hiu Yeung for your emails and for providing me with all of this information.

  Top image: Photo by me taken at Hong Kong’s Peak

  2018.01.07

• Hong Kong’s “8-units-per-floor” tower plan

  One of the pedestrian overpasses in Central has an exhibition running right now called Density 2.0. Here is a photo of one of the posters talking about Hong Kong’s typical “8-units-per-floor” tower plan.

  

  Noteworthy is the fact that the floor plates contemplate minimal tower separation distances. This allows multiple towers to be built right beside each other. As a point of reference, the guideline in Toronto is 25m between tall buildings.

  2018.01.04

• The roots of the tree

  

  Yesterday morning I attended a CTBUH (Council on Tall Buildings and Urban Habitat) breakfast event called The Story of Marketing Tall Buildings.

  It consisted of a talk by William Murray, who is Group Director of the UK-based creative agency Wordsearch, and then a panel discussion with some of Toronto’s leading developers. (David Wex of Urban Capital was one of the panelists. Many of you will probably remember him from this BARED post.)

  Shown above is one of William’s slides. The title is: The roots of the tree. And I thought it was a great metaphor for what tall buildings, well really all buildings, should aspire to do.

  The tendency is to think of buildings as objects. Here, look at how beautiful this thing is. That’s obviously important, but what about its roots? What about the way in which it interfaces with its context and hopefully gives back? Is it a catalyst for positive change?

  I thought it was a good slide.

  2017.06.22

• And the award for the tallest building of the year goes to…

  The Guardian recently published an article on vanity height in skyscrapers. What this is referring to is the unoccupied portions of tall buildings which are built purely for vanity reasons – that is, to increase the face height of the building and claim some superlative title.

  Example: 

  The tallest building in the world is currently the Burj Khalifa in Dubai. It’s 828m tall. To put that into perspective, the CN Tower in Toronto is 553m. But according to the Council on Tall Buildings and Urban Habitat, 29% of the Burj Khalifa’s height is actually unoccupied or “vanity space.” In other buildings, such as the Burj al Arab (also in Dubai), the amount of unusable space is as high as 39%. 

  For the purists out there, this of course raises the question of what should should be counted when assessing building height. Should it only be spaces where humans typically inhabit? The CN Tower has a lot of unoccupied space, which is why it is frequently excluded from these sorts of ego rankings. 

  But semantics aside, this is obviously not a new phenomenon and it’s interesting to think about this race to the sky as a proxy for what’s going on in the world. Below is a chart showing which regions have been able to lay claim to the “tallest building of the year” since 1900. 

  Since 1990, it has been all about Asia and Oceania and China and Taiwan…

  

  2017.02.05

• Residential population densities compared

  The following diagrams were taken from LSE’s Urban Age website. I’ve sorted them from lowest to highest peak residential population density. In each case I’ve also included the year of the dataset. 

  It’s amazing how much these simple extrusion diagrams can tell you about the city. It also shows you that high population densities don’t necessarily need to equate to tall buildings. Barcelona, in particular, stands out for me.

  Berlin (Peak residential density: 21,700 people/km2, 2009)

  

  Stockholm (Peak residential density: 24,900 people/km2, 2012)

  

  London (Peak residential density: 27,100 people/km2, 2013)

  

  São Paulo (Peak residential density: 29,380 people/km2, 2009)

  

  Mexico City (Peak residential density: 48,300 people/km2, 2009)

  

  Barcelona (Peak residential density: 56,800 people/km2, 2013)

  

  New York (Peak residential density: 59,150 people/km2, 2012)

  

  Shanghai (Peak residential density: 74,370 people/km2, 2011)

  

  Istanbul (Peak residential density: 77,300 people/km2, 2013)

  

  Hong Kong (Peak residential density: 111,100 people/km2, 2013)

  

  Mumbai (Peak residential density: 121,300 people/km2, 2013)

  

  2016.03.12

• To connect rather than isolate

  

  When I was
  a kid growing up in the suburbs of Toronto, I never played in the backyard. I
  played in the streets. That’s where all the kids came together.

  We would
  play baseball in somebody’s driveway, using one of the garage door “squares” as
  the strike zone. We would play football on corner lots, where it was tackle on
  the grass and “two-hand touch” on the street. And we would wax our curbs so
  that we could skateboard them.

  None of these
  spaces were ever really intended for baseball, football, or skateboarding, but
  we kids repurposed them.

  As people,
  including families, continue to move into urban centers around the world, I
  have no doubt that the next generation of children will once again repurpose
  spaces for play. But that doesn’t mean that we don’t have work to do when it
  comes to properly preparing our communities for people of all shapes and sizes.

  One of the
  most interesting design challenges facing us today has to do with our towers.

  Architects
  have long been obsessed with the idea of vertical villages. Le Corbusier’s Unité
  d’habitation in Marseille had two shopping streets embedded within the tower
  that were intended to act as public spines. I don’t know how well they did, but
  it was a highly progressive idea for the time.

  Following
  on this idea, I was recently watching a
  TED talk with architect Ole Scheeren (thanks Mariane) and I was fascinated
  by his obsession with breaking down the raw verticality of towers.

  His belief
  was that, yes, cities are and will continue to become more dense through tall
  buildings, but that most towers isolate rather than connect people. His work strives to do the opposite.

  And this
  one of the big trends that I think we will see more of in our cites. We will see
  new forms of urban connectedness and a blurring of private, public, and
  semi-public spaces. Screw Euclidean zoning.

  On that
  note, I am reminded that I owe the ATC community a post on my predictions for
  2016. I hope to get that out shortly.

  Diagram via Büro Ole Scheeren

  2016.01.22

• Taller and skinnier

  Tall buildings will sway in the wind. And when they get taller and skinnier, the swaying becomes more pronounced.

  In seismically active cities, such as Tokyo and Taipei, “tuned mass dampeners” are often used near the top of tall buildings to offset the swaying caused by an earthquake.

  But tuned mass dampeners are also found in cities like New York, so that developers can build even taller and skinnier.

  Below is a diagram from the New York Times showing what one looks like and how it works. The example tower is 111 West 57th Street.

  

  Basically the masses are tuned to oscillate at a different frequency than the rest of the tower. So when the wind blows and the tower is moving one way, the weights are moving in the opposite direction and forcing the tower back towards some sort of equilibrium. 

  Neat. Structures was one of my favorite classes in architecture school.

  2015.08.13

• Rethinking the tall building

  Back in February of this year (2015), Philip Oldfield, who is an Assistant Professor of Architecture at the University of Nottingham, gave the following talk at the Illinois Institute of Technology. Click here if you can’t see it below.

  [youtube https://www.youtube.com/watch?v=lOfkx39soIs?rel=0]

  If you’re interested in cities and how tall buildings might make them more sustainable, you’ll enjoy it. It’s filled with a number of interesting stats and takeaways, and it’s about an hour long.

  2015.07.16

• Locations of the 100 tallest skyscrapers in the world

  This morning I stumbled upon the following chart (via The Atlantic) summarizing the locations of the 100 tallest skyscrapers in the world.

  

  As you can see North America dominated tall buildings for most of the 20th century. But then in the 1980s, Asia starting building. Then in the 2000s, the Middle East started building. And today, Asia and the Middle East are where the world’s “supertalls” sit.

  What’s fascinating about this shift is that in many cases, there’s absolutely no physical or economic need to developing so tall. Yes, rising land values can drive up the height of a building, but not to the extent that we’ve been seeing.

  Instead, building “the tallest building in the world” is more symbolic than anything else. It’s about ego. It’s about asserting your position on the global stage. And so while this is a chart about tall buildings, it’s actually a pretty telling chart about global ambitions.

  2015.05.19

• The birth of tall buildings

  As an architecture and city lover, it’ll probably surprise you that I’ve never been to Chicago. I think it may have to do with the fact that it has always felt like a sister to Toronto–another Great Lakes city of comparable size. And when you travel, you often want something novel.

  But that’s no excuse. 

  Thankfully I’m happy to report that last week I booked a trip to Chicago for this August. I’ll be there for an extended long weekend. But since it’s for a bachelor party, it remains to be seen how much archi-touring I’ll actually get a chance to do.

  Chicago is a hugely important city in the world of architecture and city building. From Frank Lloyd Wright to Mies van der Rohe to Louis Sullivan, the city has deep architectural roots.

  When most people think of skyscrapers they think of New York. But in actuality, if there’s one city that gave birth to the modern skyscraper I would argue that it was Chicago. And it was made possible by the steel industry.

  Before the late 19th century, tall buildings were largely built with their exterior walls supporting most of the loads. This meant that the taller you went, the thicker the walls had to be near the bottom of the building. This is why older buildings often feel so heavy and permanent.

  But when structural steel became widely available, a new building form was created. All of a sudden architects and builders could create relatively light weight structural steel frames to support the building. The skin, or outside of the building, was no longer carrying the weight.

  That made images like this possible:

  

  For most of us today, this building under construction looks fairly typical. First the structure goes up and then it gets clad with its window and exterior skin. But at the time, this sort of construction technique–with the 3rd and 4th floors still unenclosed and the upper floors finished–would have blown people’s minds. It was an entirely new way of building.

  Steel framed buildings removed the technical limitations of building tall and also opened up entirely new possibilities for architectural expression–such as the all glass building. Today, there’s a lot of criticism around our glass buildings. But it’s interesting to note that it started as the futuristic dream of architects.

  

  Freed from the technical limitations of load-bearing exterior walls, architects such as Mies van der Rohe began dreaming of transparent, all glass buildings. For them it represented modernity. It was the future. Above is an early charcoal sketch of that dream by Mies.

  But our fixation with glass and transparency has never been because of environmental efficiency. It was about light, transparency and feelings of modernity. So as sustainability becomes increasingly critical, we should remember that there’s still lots of innovating left for us to do.

  Art and architecture has always been a representation of the time and era in which it was created–which is one of the reasons I’m so interested in technology today. It’s our era. It’s our “structural steel”. And it’s going to impact our cities.

  When posterity looks back on us and what we’ve done, I’m sure that will be clear.

  2014.06.22