Tag: urban density

• Three in four Americans believe it’s better for the environment if houses are built farther apart

  Living in a low-density place with lots of greenery and open space can feel like a pretty “green” way to live. Maybe you’ve even got a little garden where you grow delicious tomatoes. And indeed, a lot of people seem to think this is the case. According to this recent YouGov poll (which surveyed 1,000 Americans), 75% of US adult citizens believe that “it’s better for the environment if houses are built farther apart.” The number drops slightly to 68% for Democrats, but we’re still talking about a clear majority.

  

  Most experts will tell you that the opposite is, in fact, true. One of the best ways to be green is to live in a high-density urban setting and get as far away as you can from the natural environment so that you don’t screw it up. There are multiple reasons for this, but it generally comes down to the fact that cities use land and other resources far more efficiently on a per capita basis. Smaller living spaces, fewer cars, more things that are shared, and so on.

  The reason why this isn’t so obvious is that per capita thinking is perhaps harder to grasp. Living in the countryside certainly feels more green than living in the middle of New York City. But what if the 8.5 million or so people in New York City suddenly decided to sprawl outward into the countryside to consume more housing (that would then need to be heated and cooled), and then started driving everywhere (in lieu of taking transit, cycling, and walking)?

  This would be a less green outcome. It’s about the collective here, not what feels nice and green for any one individual.

  2022.04.14

• Higher gas prices impact cities differently

  Gas prices are up. And here is a chart to support this statement:

  

  If I were trying to be as sensational as possible, I would likely leave things here. But since that is generally not what I try and do with this blog, here is another chart showing gas prices over a longer time horizon.

  

  Shown this way, gas prices don’t seem as crazy. In fact, we’re only now returning to where prices were back in 2008.

  That said, these swings do impact things. And it is interesting to consider how these impacts might be felt differently across different cities.

  So here is one more chart from City Observatory looking at the average number of miles driven per person prior to COVID:

  

  One way to think about this chart is that it generally speaks to built form. Compact cities with higher densities and greater access to public transport, generally translates into people driving less.

  The result is something that City Observatory refers to as a “green dividend.” Less driving, means you save money on cars and gas. And so when gas prices go up, so does your green dividend.

  Of course, if you were to get really serious about calculating your green dividend, you’d also want to look at your housing costs, as land prices tend to decline as you sprawl outward.

  Ultimately, this is a trade off between housing costs and transportation costs (both direct and indirect, such as the cost of your time).

  But I think that there should be another dimension to this green dividend and that is the environmental benefits of less vehicle miles travelled. That too, of course, can be measured.

  2022.03.25

• Sustainable living means living in a city

  

  The UN’s Intergovernmental Panel on Climate Change (IPCC) has just published its latest climate change report. Available here. As a follow-up to this report, Dezeen spoke with Hélène Chartier of the sustainable urbanism network C40 Cities. And she makes some very good points about the importance of cities in combatting climate change.

  In fact, she goes so far as to say that sustainable living is only really possible, at scale, in cities. Because to live a more sustainable lifestyle, you need the right kind of infrastructure in place. And to have the right kind of infrastructure in place, you need density.

  This crucial point is often forgotten (though never on this blog). If you are truly concerned about climate change, then you should be for urban density. And if you are out there fighting against urban density, then your actions are undermining this global imperative.

  Chartier rightly points out that “architects have a huge responsibility” when it comes to addressing climate change. And this is entirely true. Their job is the built environment. But with all due respect to architects, the problems that need solving are ultimately much broader. Architects can only do so much if they’re hamstrung by dumb land use policies and angry neighbors, among other things.

  This needs to be a coordinated effort. We all have a huge responsibility.

  Photo by Kaspars Upmanis on Unsplash

  2022.03.17

• Cars make cities less compact

  The relationship between car ownership and urban density is a fairly intuitive one. Below are two charts from a study by Francis Ostermeijer, Hans Koster, Jos van Ommeren, and Victor Nielsen, showing how urban density is inversely correlated with car ownership. In other words, the more people with cars, the less dense that a particular place is likely to be.

  

  But there’s an interesting chicken-and-egg question here. Does Atlanta, which is near the bottom right in the above chart, have a lot of cars because it wasn’t dense enough to support other modes of transport, or did the prevalence of cars in Atlanta cause the city to spread out and become less dense? And that is exactly what the above researchers set out to determine.

  To do this, they started by looking at the presence of commercial car manufacturers in the above geographies in the 1920s. One of the things they found was that having a car manufacturer in your city at this time appears to have had no effect on population density. But over the long run, rising car ownership seems to have had a sizeable effect on reducing population densities in those places.

  The conclusion they draw from this is the title of this post: cars have made cities less compact, rather than low population densities causing people to go out and buy more cars. This makes some sense to me because cities were doing just fine before we invented cars. But like all transportation innovations that allow us to move faster over longer distances, the car encouraged decentralization.

  There are, of course, all sorts of possible implications for a finding like this. But the authors specifically mention developing countries where car ownership may still be relatively low. This is something to be mindful of because if you put most people into cars, history strongly suggests that it will impact the kind of city that you end up building.

  Chart: Cars make cities less compact

  2022.03.11

• Electrification and a modal shift — both are needed

  The Institute for Transportation & Development Policy (ITDP) is a non-profit group that works all around the world — everywhere from Jakarta to Rio de Janeiro — to design and implement both transport solutions and policies that help to make our cities more livable, equitable, and sustainable. If you’re interested in learning more about the kind of work that they do, you can download a copy of their latest annual report, here.

  Most recently, the group published a report called, “The Compact City Scenario – Electrified.” In it they argue that two things need to happen together if we are to move humanity toward net-zero carbon emissions and reduce global warming to less than 1.5 degrees Celsius by the end of the century. One, we need to fully electrify our transport (which I think is fairly obvious at this point). And two, we need a modal shift.

  

  To be even clearer, ITDP argues that both of these things need to happen at the same time in order to successfully hit our targets. Full electrification of our transport without any sort of modal shift isn’t going to cut it, and the same is true for a modal shift without electrification.

  Why all of this is important is because electrification is in many ways just a technical problem. We need electric vehicles, we need batteries, and we need the infrastructure in place to charge these vehicles. Among other things, this has meant building new charging stations, retrofitting existing buildings, and encouraging/requiring new buildings to make provisions for a future with predominantly electric vehicles.

  But for the most part, EVs allow us to continue living the way that we have already been living. Just instead of pumping gas, we now plug in our cars at the end of the day. On the other hand, encouraging a modal shift is a fairly significant behavioral change. Though we know that one of the most effective ways to encourage less driving is to build more compact cities.

  This means changing the way we live. Changing the way we get around. And accepting more intense forms of development in our own backyards. It is fundamentally linked to land use planning and so it is going to be much harder to achieve. But if you agree with the above report, we won’t be able to meet our sustainability goals without it.

  2021.12.19

• Density is not destiny

  

  Back in March and April, there was a belief that big and dense cities were going to pose a serious problem in the fight against COVID-19. The narrative was that the benefits of urban density suddenly flip to glaring negatives during a pandemic. Elevators are a problem. Public transit is a problem. Busy streets and public spaces are a problem. Instead of density, you want dispersion. There was also some speculation that COVID-19 cases would be somewhat correlated with colder climates.

  The data that we are seeing today suggests the opposite. Note the above chart by Axios. On a per capita basis, COVID-19 cases are now the lowest — and below the national average — in large US cities with populations greater than 1 million people. Where cases are the highest, again on a per capita basis, is in rural areas. Non-metro areas less than 10,000 people. The county with the highest rate also isn’t the coldest of places. It’s Childress County, Texas, where the rate is about 1,265.3 cases per 100,000 people.

  I have a lot of questions about the most important factors affecting transmission rates. Is mask wearing, for example, more important than average temperatures? What is the impact of socio-economic status? I am seeing maps that, unfortunately, suggest this plays a meaningful role. What is really driving these so-called “hot spots?” But what seems clear to me is that density is not necessarily destiny during this pandemic.

  P.S. Here’s a related article on hospital capacities across the United States.

  Chart: Axios

  2020.11.21

• Was NYC’s urban density really the problem?

  Remember when everyone was blaming New York City's urban density? (Chart from @WSJ) pic.twitter.com/JsSskG53Qa

  — Brandon Donnelly 🇨🇦 (@donnelly_b) July 22, 2020

  I posted this chart on Twitter last night. It’s from the WSJ showing new weekly confirmed COVID-19 cases in Florida, New York, and the U.S. as a whole. Now, the first thing I will say is that I relinquished my hopes of becoming an amateur epidemiologist back in April. I have no idea how this is all going to play out. But as an urbanist, it is interesting to note that back in April, many believed that New York City’s urban density was a real problem and the almost singular cause of its high number of cases (despite many other big and dense cities around the world doing much better). There was also a belief (or hope) that warmer temperatures might have a positive impact on transmission rates. That’s maybe why Florida was doing relatively better. But things have flipped. Cases in Florida are up and California just surpassed NY for the US state with the most number of cases. So who knows what will happen next. But what I do know is that wearing a mask isn’t a big deal (I have mine with me all the time) and that big urban centers will be just fine. City Observatory recently published apartment search data suggesting that dense cities have actually been getting more, rather than less, attention in the wake of COVID. That doesn’t surprise me.

  2020.07.22

• The anatomy of density

  Urban environments can be dense in many different ways. This is a topic that we have discussed on several occasions here on the blog. But this working paper by Solly Angel, Patrick Lamson-Hall, and Zeltia Gonzales Blanco — called The Anatomy of Density — is a more scientific way of looking at it. They have come up with six measurable factors that, when combined, define urban density.

  What this means is that cities achieve urban density through different kinds of built form. Hong Kong, for example, gets its density from height, even though only about 4% of its land area is occupied by residential buildings. Dhaka, on the other hand, does it through low building heights and high residential coverage. Homes occupy about 20% of the city’s area. Another dimension is crowding.

  But here’s something that may surprise you. Most cities are actually becoming less densely populated. And, despite our best efforts to encourage more sustainable forms of development, sprawl has continued to outpace densification in the vast majority of the urban agglomerations that were studied as part of this working paper. The wealthier we become, the more space we want to consume.

  Here’s a graph from The Economist that speaks to this trend:

  

  To download a copy of the working paper, click here.

  Image: The Economist

  2019.11.11

• The densest urban cells in America

  Garrett Dash Nelson recently published a study looking at urban density on a cell-by-cell basis for a number of US cities. Each “cell” is a 30 arc-second grid cell, but you can think of them as being approximately one square kilometer. The goal of the project was to better define urban density and do it in a more granular way. City averages don’t tell you a whole lot about how neighborhoods vary, and they can be skewed by the denominator you use. i.e. Where are you drawing the urban boundary?

  

  You can play around with his interactive study, here. Each city can be explored according to its 200 most dense cells. One interesting takeaway — though it is probably not all that surprising to this audience — is that New York City is really a unique place when it comes to American cities. If you look at the above chart (sourced from CityLab), you’ll see that most other US cities don’t come close to it in terms of urban density. New York’s 200th densest cell is still denser than the most dense cells of Boston, the Twin Cities, and of Dallas.

  The y-axis is the total population in each grid cell.

  2019.07.11

• Architecture of density

  Photographer Michael Wolf died at his home in Hong Kong this week. He was 64. Even if you don’t recognize the name, I am sure that many of you have seen his work. Perhaps his most famous project was “Architecture of Density”, which had him documenting Hong Kong’s extreme urban density from 2003 to 2014. Here is a photo (taken from his website):

  

  Michael was born in Germany, but grew up in Canada (he went to school in midtown Toronto) and in the United States. He eventually settled in Hong Kong and Paris — both of which became muses for his work. Michael made a career out of documenting cities and the life that happens within them. If you aren’t familiar with his work, I would encourage you to check it out here.

  Photo: Michael Wolf

  2019.04.27