Height can be deceptive: when 15 = 4

One of the foremost complaints about the proposed 15- and 11-story towers around the California Blue Line stop – a proposal that I briefly mentioned in an earlier post – is that they’re too dense for the neighborhood. What people mean by this, and sometimes what they just come out and say, is that they’re much denser than existing buildings.

The proposed towers in question.

For the record, I don’t think that “denser than existing buildings” and “too dense” are the same thing, but let’s put that aside for the moment. Are these towers actually much denser than existing buildings in Logan Square? In one sense – a visual sense – the answer is obviously yes. People associate density with height, and these buildings would be much taller than anything else around them. (As I mentioned in the previous post, the tallest building currently in Logan Square is a seven-story residential building a few blocks away; otherwise, the vast majority of the neighborhood is built at between two and four floors.)

But although visuals absolutely matter, I think people generally believe that visual density is a decent proxy for actual density, which we usually measure in people or housing units per a given amount of space. At the public meeting for this proposal, both kinds of density were brought up many times: the aesthetic density of the streetscape, as well as the number of people who would be “crammed” into a relatively small area.

The problem with this is that visual density is not actually a great proxy for actual density. This concept has been covered elsewhere by smart people in a general way, but it’s also important in ways that are specific to Chicago. Part of the issue is that, because Chicago’s buildings heights tend to be so uniform everywhere outside of downtown and the lakefront, we are extremely sensitive to anything that falls outside that range – again, typically two to four stories – but we fail to perceive the massive differences in density among different kinds of three-story buildings.

Let’s take three (and a half) examples.



Here is a typical three-flat. It has three housing units, or probably between five and eight people, on one standard 25′ by 125′ lot.



Here’s a three-story corner building. (I made up the word “corner building” because they tend to be on corners, like this one, and also because I’m not aware of any other commonly used word for them.) It’s three floors, on the same standard 25′ by 125′ lot, but now it has at least six units, housing between 10 and 15 people or so. In other words, it’s literally twice as dense as the three-flat, despite being the same number of stories.

Now, to be fair, this particular corner building has a sort of basement half-story. So maybe it’s three and a half floors. But just to drive the point home, let’s take a building that’s unambiguously shorter than our three-flat:

2 1/2.


Here’s a two-story (or, if we’re being generous, two-and-a-half) corner building on the same standard lot with four units, or between six and eight-ish people. This scans to the average person as less dense – because less tall – than the three-flat we began with, but is actually 33% denser in terms of how many housing units it has, and how many people are likely to live in it.



I’m cheating slightly here, but in a way that actually helps my case. This is, obviously, pretty much a four-story building – 3.75 stories, at the least – but I wanted to keep all of my examples in Logan Square, and it turns out that there aren’t very many courtyard buildings below four stories there.

But let’s compensate by just hacking off a floor’s worth of density. In reality, this building has about 32 units, but if it only had three floors, it would have 24. The building takes up just about three standard lots, meaning that it adds about 10.7 units per standard lot – or, in its imaginary three-story version, eight units. In other words, a three-story courtyard building has nearly three times the density of a three-flat of exactly the same height.

There’s a lot more to say about this, and its implications for planning and zoning in Chicago – incidentally, while we’ve allowed buildings to continue to be built up to three (or even four) floors in much of the city, we have outlawed corner building and courtyard building density virtually everywhere, meaning that the only way for us to get practical density is by adding lots more visual density than we’re used to.

But in this case, I want to address the particular case of the California/Milwaukee towers. For the sake of simplicity, I like turning everything into the number of units allowed per standard city lot; that way, we can directly compare new buildings to three-flats, corner buildings, courtyard buildings, and so on. The California/Milwaukee proposal contains 254 units on about 70,000 square feet of lot space. That lot space represents about 22.4 standard lots of 3,125 square feet (or 25 times 125). Doing the math, that means that there are about 11.3 units per standard lot.

To recap:

  • Three-flat: 3 units per standard lot
  • Three-story corner building: 6 units per standard lot
  • Three-story courtyard building: 8 units per standard lot
  • Four-story courtyard building: 10.7 units per standard lot
  • 15- and 11-story towers: 11.3 units per standard lot

In other words, this project would be denser than almost everything in Logan Square, but not by much. Less than a unit per lot separates it from four-story courtyard buildings, which are found all over the neighborhood, especially near Milwaukee Avenue. Rather than being four times denser than any common neighborhood building – which is a figure I’ve heard people use based on its height – it’s actually less than 10% denser.

And note, please, that I said “denser than almost everything.” Because there is, in fact, a much denser building that’s been around since early in the last century.


That seven-story building on the Square has, according to a well-placed source who opposes the California/Milwaukee towers, about 50 units. It’s on a slightly larger than normal double lot, with about 7,500 square feet. That works out to more than 20 units per standard lot – or nearly twice as dense as the proposed towers.

To be clear, none of this means that the California/Milwaukee proposal has to go through as is. It does mean, however, that we need to be clear about what kinds of precedent these towers would actually break if allowed: not a precedent of density in terms of people or housing units, but rather a precedent of density in terms of appearance. They would, in fact, be much taller than anything else in the area. Would it be possible to bring them more in line with the neighborhood’s look – if, as seems to be the case, that’s what neighbors want – without actually reducing the density of units? I don’t know what kind of engineering or economics problems that might create for the developer, but it’s worth asking.


16 thoughts on “Height can be deceptive: when 15 = 4

  1. There’s a rub in this story: required parking (required for the towers, because they’re new, but not present at the other buildings you feature because they were built before parking minimums) decreases the space on which you could construct courtyard buildings.

    So, not only does zoning prohibit courtyard buildings as you’ve pointed out, but the only way for the developer to build as densely as a courtyard building is to either build (1) the towers as proposed, or (2) build courtyard buildings atop a parking garage (aka, pretty much what you see being built in West Loop, Streeterville). Option (1) is complicated in the proposal because the developer is proposing ~67% less parking (than normally required), which will be possible for him for two reasons: (a) the ordinance that allows 50% less parking and (b) this is a planned development so it’s easier to get a variance/administrative adjustment.

    The developer doesn’t need the parking garage because of the parking reduction, but consequently must build tall because the parking will be ground level BETWEEN and BEHIND the towers. Try doing that with four-story tall courtyard buildings occupying the entire lot.

    To recap: to build at the density of courtyard buildings on this site, which is slightly less than the proposed towers’ density, you would have to build those courtyard buildings atop a parking garage.

    1. Maybe it is time for some forward looking zoning changes. IINM this development is very close to the Logan Square L stop Given that, how about trading required parking for leases that prohibit car ownership/leasing in return for landlord provided CTA monthly passes for the tenants.

      1. I don’t want to have a housing policy that prohibits any kind of transportation. I prefer housing policies, like the TOD ordinance that gives developers incentive to build MORE housing (more money for them) and LESS parking (more money for them, and for the tenant) in ways that increase a person’s ways to get around.

  2. The building isn’t too far from where I grew up, and my initial impression is that I don’t like it because the aesthetic is too different. I imagine a lot of the neighbors are scanning that first, and justifying it on other grounds.

    1. The developer did elaborate shadow studies. You can see the shadows cast at various times of day in these studies. First time I’ve seen that in a developer presentation.

  3. Best practices in urban planning call for increased density near transit stations – being out of character is intentional, because the existing character is the same whether you’re right next to the Blue Line or 1.5 miles away next to the Kennedy. That’s not a good use of the scarce land around rail stations that are expensive for CTA to service and operate.

    Anyway, I expect the next version of this proposal will bring it closer to a courtyard-building, midrise appearance without changing the unit count much. Maybe the unit count even goes up slightly to account for the lost views.

  4. I think you might be over simplifying a bit. The standard 2 or 3 flat generally has 2 or 3 bedrooms per unit, possibly housing 2 – 6 people per unit, so somewhere between 6 and 18 per lot. A courtyard building, at least the ones I’m familiar with tend to be mainly studios and 1brs with a few 2 bedroom apartments. The studios and probably the bulk of the 1 brs are occupied by 1 person, so with 10 units per lot, the range would be more like 10 to maybe 30 (I think 30 is probably way high) per lot, so probably more like twice as dense, not 3+ times as dense.

    1. That’s fair – I don’t have any solid numbers on that, but I think it’s probably true that the average unit in a courtyard building has fewer people than the average unit in a three-flat. That said, as household size has been declining pretty dramatically, I’d guess the gap between those three-flats and courtyard buildings has been shrinking, too.

    1. I bike up and down Milwaukee a couple times each week. I don’t think I’ve ever noticed this building, one block from Milwaukee/one block from Western. Any idea what neighbors who came to a development meeting for it said?

      1. It was built before my time in the neighborhood, so I don’t know it’s approval history. But I do find it interesting how a building so large can exist without any problems whatsoever that I know of. I live a few blocks away. Most people don’t even know it’s there…and I often hear “there’s never been anything as big as the proposed towers.” Yet you have this 249 unit, 12 story building. It’s for retirees.

  5. A tad off topic, but here’s an interesting take on the courtyard apartment from here in the Cincinnati area (actually Newport, Kentucky). http://goo.gl/maps/PRNnu Granted this is bigger than most 1920s era courtyard apartments that you see in Chicago, Evanston, etc., as it takes up most of a block, but by putting the parking in the courtyard, they were able to hold most of the street walls and get a good number of units without having to resort to an underground garage or filling the courtyard with a multi-story parking structure. Sure having an actual courtyard would be preferred, but this is a pretty good compromise I think.

  6. Reblogged this on urbanelijk and commented:
    Daniel Kay Hertz does a great job addressing the issue of discussing density in new proposals in this blog post. Not only does he use simple math to break down actual density versus visual density, he does so in a way that shows there is always a flip-side to every coin. Indeed, one of the commentators on the article points out density can change again when bedrooms are looked at versus units. Regardless he does a good job to force a change in our thinking of what exactly density means.

    One thing I think Hertz overlooks however (something that again is brought up in the comments section) is that opposition to density may actually be opposition to change and aesthetics. Density is merely a scapegoat that a weary public can easily attack. Hertz successfully gives a new vocabulary for discussing density, but as is the case in so many examples the feelings are probably not as much about density as they are about change.

    I think reading Hertz’s post is useful to developing better outreach strategies for new urban planning and development projects; it is also telling to see what is left out and possibly more important for extending that thinking to the sociological issues at the root of so much opposition. If models like this are successful when leading discussions about density, perhaps we can focus on the more pressing questions at the roots of community opposition.

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