Height restrictions: hmm

I should say, to begin with, that I’m not totally unsympathetic to Charles Marohn’s call for flexible height restrictions. If there were a referendum tomorrow as to whether we should replace all the density restrictions in Chicago’s zoning code with his proposed rule – you get 1.5 times the average height of surrounding buildings – I would probably vote yes. (Although I’d be more likely to vote yes if there were another clause that gave you the option of building, say, 1.5 – 2 times the width of the street your building would face, which would allow much more density on major streets like Western and Irving Park.)

But still, I’m skeptical. I’m skeptical mostly because I think Marohn doesn’t fully grapple with the trade-offs the “incremental” approach requires, at least in mature, built-up city and inner suburban neighborhoods – and because I think those tradeoffs have really serious implications both for politics, and for the sort of urban fabric/soul-of-the-city questions that he seems to care a lot about.

Let’s take, for example, the two high-rise apartment buildings that have been proposed next to an L stop in my neighborhood. At 11 and 15 stories, the taller one would be roughly twice as tall as anything in the neighborhood (there’s an eight-story building a few blocks away), and roughly four times taller than the standard three-to-four-story building canopy in the area. This is exactly the kind of non-incrementalism that Marohn opposes, and I’ve heard more than a few people express the feeling that they’d rather see all those units come to the area in the form of more traditional three-flats than a big and flashy new tower.


But what would that actually look like? The towers are supposed to have roughly 250 apartments. That’s 84 three-flats, or roughly four full block faces. But if each of those three-flats is replacing a single family home or two-flat, then you’re not getting three new units in each building – you’re getting one or two. To get 250 new units, you would have to tear down 100 two-flats and 75 single family homes and redevelop them as three-flats: 175 old buildings, or roughly nine block faces. If we want to concentrate this density near the same L station, that basically means that every adjacent block would be entirely demolished and rebuilt with modern three-flats. Even if we discount the units that could be built on the empty lot where the towers are proposed – something that exists in very few places in Logan Square, or in most other neighborhoods in the city where development is occurring – we’re still talking about the wholesale destruction of at least a hundred historic buildings.

This, obviously, is a problem. It’s a problem from a logistical point of view, because assembling 100 or 175 or whatever separate properties is obviously harder, and probably more expensive, than buying a single, larger property. (And though Marohn has responded to this criticism by saying that he doesn’t care about the cost efficiency of construction, anyone who cares about housing costs, and the social problems related to ones that are too high, should.) It’s a problem from a preservationist point of view, because you’re requiring the teardown of historic buildings and streetscapes at a massive scale. It’s a problem from a Jacobsian urban planning point of view, because you’re eliminating the older building stock that provides most of the cheap housing and commercial spaces that create space for diversity in neighborhoods like Logan Square. And it’s a problem from a political point of view, because people generally don’t like it when every single building on their block is torn down and replaced with something that looks completely different.

I’m not sure how much the historic preservation and Jacobsian old-building issues bother me, or if I could deal with them. I am more confident, however, that the people who don’t like having a tall new building a block or two or three away from them would not be any happier about having all, or half, or a third of all the buildings on their street torn down. I could be wrong! And if I am, okay.

But the fact is that the kind of incremental development Marohn is championing is pretty rare, at least on a scale that would come close to matching the housing growth from a handful of very dense projects like the towers above. One of the only examples I can think of are some of the inner neighborhoods of Houston, where a loosening of density restrictions in the late 90s has unleashed a wave of townhome and small apartment developments in formerly single-family-home areas.

There used to be quaint old little homes here. Credit: cdandrews.com

But Houston is obviously an outlier in the laxity of its building regulations, at least in neighborhoods like this one. (And people there aren’t necessarily happy about it.) Otherwise, the North American successes I’ve heard of in outlying neighborhoods – especially around transit – have come from targeted, out-of-scale development right around rail stations in places like Toronto, Vancouver, and suburban DC.

These two blocks are about a quarter of a mile from each other in outlying Toronto. Dense towers, protected single family homes.
These two blocks are about a quarter of a mile from each other in outlying Toronto. Dense towers, protected single family homes.

I should also say that part of the disagreement here, I think, comes from the fact that Marohn and I live in very different places. Marohn is from a small, generally auto-oriented town without, I would imagine, a huge pent-up demand for housing, and without the same kind of historic housing stock that people in places like Chicago are attached to. (Although maybe people there are attached to their housing too: I don’t know.) In any event, the case for new, large residential projects to inject as many housing units as possible, especially near transit, is clearly much weaker in the kind of place Marohn lives than where I or many of his detractors on this issue live.

Which is to say that I’m sort of sympathetic to his argument, and I think that in some contexts, he’s probably correct. But the costs and benefits of what he’s proposing in Chicago are very different from the costs and benefits in a place like Baxter, Minnesota, and I think he ought to be a bit more up front about that.


11 thoughts on “Height restrictions: hmm

  1. Great points.

    While I admire Marohn’s desire to see more incremental development, I think there’s a misunderstanding between looking at the final outcome of incremental development and understanding how it actually happens. The reality of the development process is that the decision-making for each individual parcel is a lot more binary; consequently the end result is a process that lurches from state to state. It’s not a smooth curve, it probably looks more like a staircase.

    The other point is the general unworkability of such a regulation, as intriguing as the concept may be. Realistically, the best you’re going to do is something akin to Houston, which is more about deregulating than trying to micro-manage too closely via an odd and potentially legally problematic ratcheting height regulation.

  2. “I think he ought to be a bit more up front….”

    Ok. Disclaimer: My suggestion for a dynamic height limit — as with everything we discuss at Strong Towns — has many local nuances that would depend greatly on the actual city, neighborhood and location. My sample ordinance language of 1.5 is not a ratio I meticulously researched and developed but one that I gave as an example of how simple such a dynamic height standard would be to apply. And yes, I am less discussing the New York, DC, Vancouver and Chicago situations as I am the 99% of the rest of the North American land area, although I think the same logic would ultimately apply.

    All this being said, the point I made was that towers next to residential homes distort the underlying property values and take small players out of the market. Nobody has touched on that aspect — the push back I have received has been like this, a defense of high rises — but your example of having to tear down blocks of houses to get the same density (another much-abused term I have disdain for) is a result of this effect.

    Glad you are reading and appreciate the thoughts.

    1. Thanks for the comment.

      Having to tear down blocks of houses is a result of what effect, though? Of pushing small players out of the market? I’m not sure that’s true – and in either case, it’s also obviously an effect of not allowing denser development like these. I’m not sure where the gain is, if this is happening either way.

      I guess I suspect that people are talking about the small players thing less because it just doesn’t seem like the main problem facing housing in big cities. I’m with you that it should be better, a) isn’t the issue lending standards more than land values? and b) fixing the small lender problem at the expense of fixing the housing supply problem doesn’t seem like a tradeoff that makes sense in places like Chicago.

      1. What would have happened if some sort of incremental density regulation was made law of the land fifty years ago? Would places like Chicago and NYC have built up the same sort of pentup demand for housing? How many blocks of detached single family housing and low rise rowhouses would have been replaced with something denser by now? You wouldn’t have had mega developments, but maybe they wouldn’t have been needed. Maybe with the pentup demand that exists in some markets incremental density doesn’t work on its own, but together with targeted exceptions allowing larger buildings to pop up right away around transit stops or other areas where large increases in density can be more readily absorbed, can lead to a more rational housing market moving forward.

      2. If there was an automatic right to build 1.5 times the density of the surrounding buildings, no, I don’t think we’d have a pent-up housing demand problem – or if we did, it would be much, much more localized. On the other hand, many, many blocks of the city would be totally unrecognizable. Which is maybe fine! But it’s a thing.

    2. Saying that the tower distorts the values of adjancent homes maybe true, but that also needs some more context as to how that tower was built and financed in the first place.

      If there really is the demand for those housing units, then it’s not a surprise that those kinds of increased valuations may be appropriate. And I don’t want to discount the very real problems you can run into when you have a gap between the development required to justify the land valuation and what the market can acutally support. However, of all the potential policy tools to address that, I’m just not seeing how the height limit is a good choice.

      Perhaps a lot of this depends more on the context – those kinds of towers in a place like New York, DC, or Chicago are facing funamentally different housing markets than the less intense housing markets in other places.

  3. I agree with Alex B., and I think the mention of Houston gives a clue as to a prescription for enabling more of the incremental development that I and Marohn would both like to see more of. Houston’s wave of redevelopment was spurred in particular by a loosening of minimum lot size requirements, which suddenly made it feasible to subdivide the existing large-lot single-family home properties. Before that point, developers effectively had only one economical option: tear down the house and replace it with a significant apartment building, as that was the only way to justify investment in a large indivisible chunk of valuable land.

    Demand for such structures is limited, however, and political opposition to them often intense, so you will tend to see the pattern in the rendering above, with just a few tall apartments next to single-family houses. Allowing the land to be subdivided into very small parcels, however, seems to unleash the forces of incrementalism. The urban land market suddenly becomes open and available to the small developer, to the local builder, or even to the white collar professional. If you want incremental redevelopment, in other words, you need to allow the commodity used to provide that building — land — to be provided in increments as well. An adjustable height limit conceivably could provide a simulacrum of incrementalism, but only that.

    There are concerns about inequality and concentration of wealth implicit in these sorts of debates as well, and I’d it to Thomas Jefferson (in a letter to James Madison) to have the last word as to the connection between equality and land subdivision: “I am conscious that an equal division of property is impracticable. But the consequences of this enormous inequality producing so much misery to the bulk of mankind, legislators cannot invent too many devices for subdividing property, only taking care to let their subdivisions go hand in hand with the natural affections of the human mind.” Jefferson was talking about large landholdings and the practice of entailing estates, but I think the basic point is just as relevant to contemporary American cities.

  4. I think transit is too big of a defining characteristic to be ignored or generalized around. The Logan Square development proposals are smart TOD, but just 1.7 miles down the road in Chicago: the Lathrop Homes 28 story re-development boondoggle of a proposal that’s 1.5 miles from the nearest CTA station is a terrific example of “bad density” / “high rises in parks”.


    You can have a policy of incrementalism when you start from scratch, but if 100+ years of urban development in the context of poor zoning law precedes it, you’re just slowing down / inhibiting smart development.

  5. Super interesting debate all around, particularly in regards to the Logan Square development. For the record, I’m not sure how I feel about the Logan Square towers. It’s difficult to balance likely outcomes with theoretical ideals. I would consider myself a theoretical supporter of dynamic height limits.

    I’m assuming we’re starting this discussion of common agreement: that increased TOD density is a generally good thing.

    A couple of things I think you’re downplaying or ignoring:

    1. I think you’re creating a straw man with your base case scenario. The alternative to 250 apartments isn’t 0 apartments, it’s most likely 100-150 apartments (assuming a 40-60% reduction in height). That leaves 100-150 apartments to make up for if our goal is equivalent density delivered by shorter buildings.

    2. I think you’re creating a straw man with your alternative case scenario. The alternative isn’t by necessity 3-flats, and it doesn’t require a confrontation with conservationists. You don’t have to look far to find alternatives for increased density other than occupied historic housing: how about directly across the street at the enormous unused surface parking lot and abandoned family dollar building? That land could probably absorb 50 units without exceeding 3 or 4 stories. How about the enormous vacant lot directly behind Chase? Almost the entire south side of Milwaukee for 3 or 4 blocks south of the towers is surface parking, vacant lots, unoccupied recent construction, or mostly unoccupied non-historic buildings. In fact, no one (reasonable) would bat an eye about taking down and adding density to 50% of the stretch of Milwaukee between California and Damen – it’s pretty underutilized and bleak.

    3. I’m not sure Charles’ economic argument is applicable to the Logan Square development, but there is a corollary argument. We can pretty safely assume that the increasing demand for Logan Square housing will induce increased supply. The question is how we manage those supply increases, and on what timeline we’re going to accept them. In so much as a mega-development will satiate demand, there will be less economic incentive for additional supply, meaning that small scale developments become less likely. All those alternative paths for dense supply in #2 are incrementally less likely with every story added to the Logan towers. At this moment, increased density in Logan Square is an inevitability and the further we concentrate it, the less it is likely to spread as infill over time.

    4. Don’t want to rehash an argument I’m not qualified to make, and am not sure I agree with, but in so far as Pete Saunders might have it right on increasing supply in gentrifying neighborhoods disincentivizing an equitable spread of investment, even more reason to err on the side of slightly less height.

    5. This is essentially a probabilistic question. (The likelihood we’re right not to build at this height) = (Probability Pete is correct on decreased equitable neighborhood investment)+(Probability Charles is right on the detrimental effects of unfettered building height). At the end of the day, absolute surety is impossible, and we’re making a probabilistic assessment, right? And a conservative approach in line with historical standards (the ones that aren’t low density) is almost certainly a better probabilistic bet, right? You might not solve for gentrification and transit access, but you won’t ruin the urban fabric either.

    Out of curiosity, what would you describe as your “ideal” project in terms of density and height for the lot? Exactly as proposed? 20 stories? 100 stories?

    Do you think there is a substantially negative effect to adding 250 units to the neighborhood over 10 years rather than 3 years? Is slow density inherently worse density?

    Anyway, your commentary is much appreciated. Great insight, great additions. These sort of public discussion spaces are awesome for interested lay people like me. As a realist: I will probably argue for the merits of the development when discussing it with a NIMBY or car-centric crowd with the hope of increasing positive public sentiment so that the project goes forward after the inevitable retrenchment.

    1. This is thought-provoking, but also a lot, and I’m not sure I can respond thoroughly. But here goes:

      1. In this particular case, there’s a large open lot, yes – I actually did mention that it could absorb some of the units. Either way, though, the larger point stands, I think – incremental density increases require demolishing huge numbers of older buildings. In a few places, as in Milwaukee between the Congress Theater and California, there are a number of open lots and parking lots that, if their owners decided to part with them, could be built up with little to no demolition required. But in most of the city neighborhoods with development pressure, including most of the rest of Logan Square, that’s not really the case.

      2. See #1.

      3. I think this is really important: we absolutely cannot assume that increasing demand for housing in Logan Square will result in increased supply. In Lincoln Park, for example, increased demand for housing has led to *decreased* supply, as it has, I believe, in Lakeview. In other parts of the wealthy North Side, supply has been stagnant or growing very, very slowly. The idea that we’re going to sate housing demand with 250 units, I think, is just not correct. I think a key assumption – I’m tempted just to say fact – of the situation is that there’s no way we’re ever going to catch up to housing demand in Chicago’s gentrifying and gentrified North Side; all we can do is come as close as we can. To the extent that we lower prices enough to deter the redevelopment of older housing stock, I actually think that’s a good thing, because it’s affordable market-rate housing that we’ve preserved in a privileged area.

      4. Not to get into this again too much, but: A. You have to distinguish between people and places. Holding down supply will probably bring investment to more places; it will also deny more *people* access to privileged neighborhoods and their resources by increasing segregation. B. The parts of the city that are most in need of investment won’t get it through this process; a good amount of research has found that poor black neighborhoods almost never gentrify, and that has certainly been the experience in Chicago, even where they’re in a clear path of gentrification.

      5. I would dispute that “a conservative approach” means “the zoning regime we’ve had for the last 40 years.” In fact, virtually all of Logan Square – the urban fabric that we’re trying to defend – is the product of a radically different legal approach to planning than the one we currently have. The current legal approach, on the other hand, is widely believed to be a major factor in the rise of income segregation in Chicago and elsewhere. I also don’t really know what it would mean to “ruin the urban fabric” – how would this tower do that?

      I don’t think I have an “ideal” project. My ideal project would come as close to meeting housing needs as possible. But I don’t really think that, from an urban fabric point of view, it makes a terribly large difference if the project is 3, 8, 15, or 40 stories. Sure, to some extent those different heights would create different feelings on the ground. But I’ve been to cities that feature all of those heights, and combinations thereof in the same neighborhood, that were all successful, vibrant urban areas. I’m just not convinced that it matters that much.

      Yes, the downside to adding it over 10 years is that you’re reducing the rate of increase of supply while the rate of increase of demand stays the same, which will increase prices and speed displacement.

      Thanks! This kind of discussion is always fun.

  6. All good stuff. Trying to keep it a bit shorter:

    1+2: I generally agree with what you’re saying, but would reiterate that in the case of this particular development there are alternative avenues for density (and TOD alternatives). In so far as owners aren’t willing to part with their lots, I think that lends credence to Charles’ economic argument – and if we establish this corridor as a location for 10+ story developments, it will increase the asking prices of the vacant lots (and, just riffing here, but likely limit the pool of developers to those with the most access to capital – a pool of mostly national companies with primarily suburban development experience, and business models predicated on corporate tenant anchors).

    3: Your point is well taken, and, I think, your strongest. I wish there was a larger body of accessible data-driven work on density as it relates to cascading development. Your comments make me ponder an alternate dynamic code proposal: dynamic density tied to median rent. Imagine a city that automatically pre-approves density to maintain rent at inflation. Fascinating.

    4: I see both sides, and don’t have the expertise to really comment. I assume you’re mostly referring to Robert Sampson’s new work. Super intriguing stuff. My big thoughts on it are that I don’t think he’s made (or is trying to make) the case that the racial patterns are immutable and future proof, and I don’t think anyone is considering the possible effects of minority capital as a force of gentrification in the future.

    5: By conservative approach, I meant pre-1940s patterns, but you make a good point in that I was pushing a false alternative.

    On urban fabric:

    This is in large part an aesthetic experience argument, and I’ll admit that I’m an unabashed aesthete. I think that because aesthetic questions are so qualitative we undervalue their importance. Not wishy-washy importance, but real, quality of life, economic utility, long term usability importance. Aesthetics are just hard to measure and predict, so we choose to ignore them for qualities that are easier to control for (which makes sense). I think outsized height is *generally* bad aesthetics. (to pre-empt, I have no bias towards “old” things, and have zero patience for people who complain about projects based on preferred style regimes)

    The more hard-logic objective “urban fabric” argument I would make relates to the size of a building as a proportion of the surrounding neighborhood. If a building is far larger than its surroundings, then its failure can have a profound effect on the neighborhood. We don’t have to look far for an example: see the congress. Smaller scale developments are less deleterious in the case of failure (and failure could include a number of things: maintenance, market, management, aesthetic, usability etc.). This is what I mean when I describe incremental development as conservative and as less threatening to the urban fabric.

    I want to be convinced on density as panacea, but, even though I don’t have the backing evidence, I just can’t banish the thought that we’re not accounting for the the networked interdependence of a city, and the unexpected results of asymmetrical density. I see all the benefits of adding density, but I can’t wrap my head around how that relates to 1: nearby development 2: a flat total population, or 3: the parts of the city that are far more seriously underpopulated.

    Thanks for the response.

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