Daily Archives: January 22, 2010

The next tallest skyscrapers (and how vertical sprawl is better than horizontal sprawl)

A few weeks ago the Burj Khalifa in Dubai was officially anointed as the tallest skyscraper in the world. As tall as it is (2716.5 feet, or approximately 828 meters for everyone outside of the U.S.) it may barely break the top ten of tallest buildings in the world within the next decade. These buildings (some of them proposed, some of them merely dreams), as listed on the Popular Mechanics website, will not only reach higher than the Burj Khalifa but in some cases dwarf the current tallest building in the world.

There is nothing new about dreaming up the tallest building in the world. Frank Lloyd Wright designed (at least in a preliminary/schematic approach) a building that was to be a mile tall (5,280 feet for anyone outside the U.S. that has absolutely no idea what a mile is). (As seen at this website, along with some other buildings that have yet to come to fruition.)

Of course there are a lot of technical issues with constructing a building as tall as these. One issue is the requirement of constructing a large enough foundation to anchor the mass of the building as well as handle the intense horizontal loads created by the wind (especially the more intense velocity of the wind at the heights of the skyscrapers) hitting the profile of the building. Another issue is creating a floor plan large enough so that it’s not primarily occupied with vertical circulation (such as stairs and elevators) and other shafts for mechanical ducts, and yet small enough so that a majority of the floor is near windows (this is for providing natural light to most spaces, which makes sense in regards to a physiological need because people need sunlight, and in regards to a financial standpoint because nobody wants to lease expensive office space unless there’s an abundance of natural light).

And another technical issue for these skyscrapers that is just as important is the ability to evacuate the building in case of an emergency (such as a fire or an attack). Tall buildings, especially ones reaching the heights of these proposed skyscrapers, must have ample egress and, because elevators (and in some jurisdictions escalators) are not considered proper means of egress, the stairs would have to be wide enough to accommodate the number of people working and residing in these skyscrapers. But of course the Burj Khalifa was constructed, so obviously these issues must have been solved.

I’m reading Green Metropolis (David Owen), and one of the interesting points the author makes is the inherent sustainable strategy that New York City provides by being a vertical city instead of a horizontal city. Skyscrapers provide a means that appears to make sense to being green – design for more people living on the smallest piece of land possible. The compaction of New York City forces residents to forgo the automobile as their primary means of transportation because most everything they require is in close proximity. The dense population also provides the necessary density to properly support public transportation.

I’ve heard it said that skyscrapers were designed to be monuments driven by ego and testosterone. I’m sure that is true, but the flip side is that these tall buildings provide a unique and theoretically simple means for creating a smaller physical footprint for living on, which leaves more land for food production and ultimately nature.

Imagine if our entire built environment emulated Frank Lloyd Wright’s Broadacre City, where every single family in the country was given one acre to live on. (There are more dense parts of Broadacre City that included office buildings and apartments, but the core premise to the city would be that most families would each live on one acre.) Sure everyone could live closer to nature and frolic in the woods, but think of the amount of roads and other utilities (such as water and electricity) needed to connect to every residence, and the amount of police and fire protection needed to provide a quick enough response to each residence in case of emergency, and the amount of walking for kids trying to trick-or-treat (it could help cure the obesity problem in this country, although most kids would say “screw it” after going to only two houses).

If you know the reduce-reuse-recycle mantra of creating a more sustainable environment, you will understand that cities can become more ecologically responsible by reducing the amount of land for human occupation by growing vertically and not horizontally.