History of Extreme City Density thread

[memph]

Originally Posted by Gava

I doubt the residential structures of Rome occupied even 10% of the city area, even though they contained something in the ballpark of 80-90% of the population.

For example, the densest city block in Barcelona sits along carrer del Paraguai, it has close to 300.000 inh per sq km, yet the neighbourhood has a density that is not even 1/20th of that.

Now, compare this city block in Barcelona that has 15-20 sq meter of living space per inhabitant (50-100 sq meter apartments) with ancient Rome were people lived in housing blocks were you would not find anything but people sleeping on the floor, 1 person per sq meter of gross floor area is a conservative number.

The reason that neighbourhood in Barcelona is so much less dense (fyi it's <15x not >20x) is in large part because a huge chunk of it is dedicated to industrial uses. Also because the average residential block is much less dense than that one. I'd expect 30.000-90.000 /km2 would probably be more typical of a residential block in Sant Marti.

[nei]

Originally Posted by Gava

Ancient Rome definitely qualifies as one of the densest cities ever built, and it probably had the highest living density any city ever had. The majority of the population lived in apartment blocks 5-6 stories tall, tightly packed with only narrow allies in between them, each building housing hundreds of people, and the apartments were basically singular rooms packed with people, all people did in those buildings were sleeping.

A number of pre-industrial cities had a similar population to Rome: Alexandria, Baghdad and several Chinese cities. Why would Rome have been so different?

[muppet]

This all depends on the population estimates for Rome. Some sources put it that Rome only ever reached 450,000, 800,000 at the most. The ones that do put it over 1 million also state Alexandria reached that figure a century before. - and of course there's significant variation on whether Alexandria reached it too.

[Astorian]

Originally Posted by nei

Barcelona is close to NYC/Manhattan in residential density, despite the lack of high rises.

This only true when you discount the parks and other sparsely population regions of Barcelona, but include those same types of regions for Manhattan when calculating density. A lot of Manhattan is office space, meaning no-one lives there, yet that area must included to make this statement factual. Also, this doesn't take into account the population swell that occurs in Manhattan during the day (population more than triples during the weekday.) There really is no comparison between the two. Barcelona sure is gorgeous, though.

[memph]

Originally Posted by Astorian

This only true when you discount the parks and other sparsely population regions of Barcelona, but include those same types of regions for Manhattan when calculating density. A lot of Manhattan is office space, meaning no-one lives there, yet that area must included to make this statement factual. Also, this doesn't take into account the population swell that occurs in Manhattan during the day (population more than triples during the weekday.) There really is no comparison between the two. Barcelona sure is gorgeous, though.

Barcelona's city proper density is considerably higher than New York's and includes a decent amount of low density around the port and mountains (I'd say a higher % than Manhattan but maybe lower than NYC). Regarding Manhattan, I'd give Manhattan the edge but Barcelona is definitely ahead of NYC as a whole.

Weighted density (which would be unaffected by Central Park)
Manhattan: 113,536 ppsm (2000)
New York: 64,025 ppsm (2000)

Barcelona: 80,362 psm
Barcelones County: 85,686 ppsm (includes Barcelona and 4 inner suburbs)

However, Barcelona's numbers were not calculated with census tracts but neighbourhoods, which are larger leading to Barcelona's weighted density to be underestimated. The neighbourhoods were the smallest unit I could find for Barcelona, so to make it apples to apples, I'll combine census tracts for Manhattan.

Combining sets of 3 census tracts for Manhattan (average of 16,695 pop - compared to 16,584 for Barcelones and 22,290 for just Barcelona)
Weighted Density = 88,432 ppsm

So it's very close actually, especially when you consider Barcelones is more populous than Manhattan.

Daytime densities are different, I doubt Barcelona has as much of a daytime increase being a much smaller city. Also I suspect Barcelona has a bit less living space per capita than Manhattan.

[nei]

Eixample in Barcelona has a density of 92,000 per square mile. The Upper East Side, the densest neighborhood in Manhattan, has a density of about 120,000 per square mile. And plenty of Barcelona is at Eixample level density:

The 30 most densely populated neighbourhoods accounted for 57.5% of the city population occupying only 22,7% of the municipality, or in other words, 936,406 people living at an average density of 40,322 inhabitants per square kilometre.

[Astorian]

Originally Posted by memph

Barcelona's city proper density is considerably higher than New York's and includes a decent amount of low density around the port and mountains (I'd say a higher % than Manhattan but maybe lower than NYC). Regarding Manhattan, I'd give Manhattan the edge but Barcelona is definitely ahead of NYC as a whole.

Weighted density (which would be unaffected by Central Park)
Manhattan: 113,536 ppsm (2000)
New York: 64,025 ppsm (2000)

Barcelona: 80,362 psm
Barcelones County: 85,686 ppsm (includes Barcelona and 4 inner suburbs)

However, Barcelona's numbers were not calculated with census tracts but neighbourhoods, which are larger leading to Barcelona's weighted density to be underestimated. The neighbourhoods were the smallest unit I could find for Barcelona, so to make it apples to apples, I'll combine census tracts for Manhattan.

Combining sets of 3 census tracts for Manhattan (average of 16,695 pop - compared to 16,584 for Barcelones and 22,290 for just Barcelona)
Weighted Density = 88,432 ppsm

So it's very close actually, especially when you consider Barcelones is more populous than Manhattan.

Daytime densities are different, I doubt Barcelona has as much of a daytime increase being a much smaller city. Also I suspect Barcelona has a bit less living space per capita than Manhattan.

Where are you getting these figures? I'd like to compare them to my sources. Barcelona (1.615 million) and Manhattan (1.619) have practically the same population. The difference being however, Manhattan has a land area of 22.9 sq miles vs Barcelona's land area of 39.34 sq miles. Of course, 90% of Barcelona's population (1.45 million) lives on 51% of Barcelona's area (20.01 sq miles.) Thats the only way you get similar numbers to Manhattan. But this includes central park and all the office space in Manhattan, which is a lot. It's hard to separate exactly how much of Manhattan's land area is office space because of how interwoven residential and office space is in the city. However, given that Manhattan is home to both the largest and 3rd largest office districts in the US, it's safe to say a substantial amount of Manhattan's 22.9 sq miles in office sp.

That being said, you simply cannot do an apples to apples comparison of Manhattan to Barcelona because Manhattan is not it's own city, but rather just the economic center of NYC. Which is why Manhattan's density about triples during the day.

[chris08876]

^^^^^^^
There was a great study done by NYU showing the daytime population of Manhattan. It is close to 4 million people on the island on any given weekday.

Here is the source for anyone interested in reading it, its a great read: http://wagner.nyu.edu/files/rudincenter/dynamic_pop_manhattan.pdf

------------------------

Just the introduction to get an idea:

We cannot understand Manhattan in the 21st
century by relying on conventional
measures of urban activity. Simply put, Manhattan consists of much more than its residential population and daily workforce. This island, measuring just 22.96 square miles, serves
approximately 4 million people on a typical weekday, 2.9 million on a weekend day, and a weekday night population of 2.05 million. Manhattan, with a residential population of 1.6 million more than doubles its daytime population as a result of the complex network of tunnels, bridges,
railroad lines, subways, commuter rail, ferry systems, bicycle lanes, and pedestrian walkways
that link Manhattan to the surrounding counties, cities and towns.
This transportation infrastructure, largely built during the twentieth century, is operated by the City of New York, Metropolitan Transportation Authority, and Port Authority of New York & New Jersey. The infrastructure network generates a constant flow of people who are
responsible for Manhattan’s emergence as a world capital for finance, media, fashion, and the arts. The residential population count does not include the 1.6 million commuters who enter
Manhattan every weekday, or the hundreds of thousands of visitors who use Manhattan’s tourist
attractions, hospitals, universities, and nightclubs. This report analyzes the volume of people flowing in and out of Manhattan during a 24-hour period; we provide an upper estimate of the
actual number of people in Manhattan during a typical work day.

================================
================================
The Dynamic Population of Manhattan
Mitchell L. Moss and Carson Qing
March, 2012
http://wagner.nyu.edu/files/rudincenter/dynamic_pop_manhattan.pdf
http://wagner.nyu.edu/blog/rudincenter/day-of-week/

[nei]

Originally Posted by Astorian

Where are you getting these figures? I'd like to compare them to my sources. Barcelona (1.615 million) and Manhattan (1.619) have practically the same population. The difference being however, Manhattan has a land area of 22.9 sq miles vs Barcelona's land area of 39.34 sq miles. Of course, 90% of Barcelona's population (1.45 million) lives on 51% of Barcelona's area (20.01 sq miles.) Thats the only way you get similar numbers to Manhattan. But this includes central park and all the office space in Manhattan, which is a lot. It's hard to separate exactly how much of Manhattan's land area is office space because of how interwoven residential and office space is in the city. However, given that Manhattan is home to both the largest and 3rd largest office districts in the US, it's safe to say a substantial amount of Manhattan's 22.9 sq miles in office sp.

I don't think office space takes up as much as you'd expect because of skyscrapers, however some areas would be hard to separate between residential and office. This map could be useful:

http://www.joelertola.com/grfx/population/d_n.html

[memph]

Originally Posted by Astorian

Where are you getting these figures? I'd like to compare them to my sources. Barcelona (1.615 million) and Manhattan (1.619) have practically the same population. The difference being however, Manhattan has a land area of 22.9 sq miles vs Barcelona's land area of 39.34 sq miles. Of course, 90% of Barcelona's population (1.45 million) lives on 51% of Barcelona's area (20.01 sq miles.) Thats the only way you get similar numbers to Manhattan. But this includes central park and all the office space in Manhattan, which is a lot. It's hard to separate exactly how much of Manhattan's land area is office space because of how interwoven residential and office space is in the city. However, given that Manhattan is home to both the largest and 3rd largest office districts in the US, it's safe to say a substantial amount of Manhattan's 22.9 sq miles in office sp.

That being said, you simply cannot do an apples to apples comparison of Manhattan to Barcelona because Manhattan is not it's own city, but rather just the economic center of NYC. Which is why Manhattan's density about triples during the day.

I calculated weighted density using data from here: http://www.bcn.cat/estadistica/angles/dades/barris/index.htm
Don't remember what year it was from, I calculated that a while ago, it might have been 2010 or 2011 numbers.

[Tyler Xyroadia]

Any discussion of Ultra Dense Living is meaningless without taking into consideration ultra dense BUILDINGS.

A city of several million is meaningless when spread over a vast surface area.
In order to consider long term sustainability you have to think of buildings AS cities, otherwise know as Arcologies
I invite everyone to take a look at the ideas and principles behind it

Also some images to give you an idea of what "Arcologies" would be like.

[jd3189]

^^^ Interesting as well. We might as well start talking about the future of extreme city density in the form of buildings.

[Wizened Variations]

Originally Posted by Tyler Xyroadia

Any discussion of Ultra Dense Living is meaningless without taking into consideration ultra dense BUILDINGS.

A city of several million is meaningless when spread over a vast surface area.
In order to consider long term sustainability you have to think of buildings AS cities, otherwise know as Arcologies
I invite everyone to take a look at the ideas and principles behind it

Also some images to give you an idea of what "Arcologies" would be like.

You indirectly bring up an interesting argument about energy efficiency and population density. Dense buildups like Kowloon are far more efficient, IMO, than huge mega structures when the cost of construction is factored in. While the efficiencies of 20,000 or so people in a structure could be made higher than say 20k people in a dense conglomeration of small buildings, the construction costs per person are no where near the same: initial construction costs might be 100x higher and this cost would have to amortized over the life of the structure as well the interest costs on the money required to build such mega-structures.

With the inevitable rise in the cost of materials and energy, IMO, such structures if built will be directly or indirectly built by governments as show pieces, financed by taxes paid by millions who will not be able to live there.

[memph]

Originally Posted by Wizened Variations

You indirectly bring up an interesting argument about energy efficiency and population density. Dense buildups like Kowloon are far more efficient, IMO, than huge mega structures when the cost of construction is factored in. While the efficiencies of 20,000 or so people in a structure could be made higher than say 20k people in a dense conglomeration of small buildings, the construction costs per person are no where near the same: initial construction costs might be 100x higher and this cost would have to amortized over the life of the structure as well the interest costs on the money required to build such mega-structures.

With the inevitable rise in the cost of materials and energy, IMO, such structures if built will be directly or indirectly built by governments as show pieces, financed by taxes paid by millions who will not be able to live there.

Agreed, and even putting aside building costs, wouldn't it be pretty expensive to pump water all the way up there? Not to mention how many elevators would you need to service such a beast? It's kind of like vertical sprawl, instead of a community spread out horizontally requiring lots of highways, it's a community spread out vertically requiring lots of elevators.

[Gava]

Originally Posted by Tyler Xyroadia

Any discussion of Ultra Dense Living is meaningless without taking into consideration ultra dense BUILDINGS.

A city of several million is meaningless when spread over a vast surface area.
In order to consider long term sustainability you have to think of buildings AS cities, otherwise know as Arcologies
I invite everyone to take a look at the ideas and principles behind it

Arcologies will never be built, they are to expensive, require to many resources during construction and still have unresloved conceptual problems. The only Arcology that was even close to reach a greenlight was the Tokyo Millenium tower http://www.fosterandpartners.com/projects/millennium-tower/ that was based on the ridiculous property bubble in Japan during the 1980s. https://en.wikipedia.org/wiki/Japanese_asset_price_bubble

They then tried to shop it around in China, Taiwan and Corea but unless we see property prices again like those in Japan, forget about ever seeing another serious atempt to build an Arcology.