Density and Height
(cc photo by dionhinchcliffe)
Beyond DC makes the point that “density” and “tall buildings” are not synonymous. And, indeed, they’re not. You have parts of the country that basically consist of tallish buildings surrounded by large plazas and parking facilities that are all separated from each other by very wide roads. That kind of tall buildings is not a path to walkable urbanism or environmental sustainability. All very true.
That said, in the specific context of the Washington DC central business district, building denser and building taller largely are synonymous. If you walk around, essentially every building has the largest footprint it’s allowed to have, and essentially every building is built-up to the (very low) maximum height permitted. Downtown Washington has by far the most transit connectivity of any place in the metropolitan area, and so putting more stuff there as opposed to someplace else would make the region more environmentally friendly. But the only way to fit more stuff into Downtown Washington would be to either pave over the National Mall (bad idea) or else build some taller buildings.
50 Responses to “Density and Height”
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June 26th, 2009 at 12:54 pm
With the key point being that the city road network was designed in an age before cars.
June 26th, 2009 at 12:54 pm
so… propose an actual, articulated solution. the current code right now is a building can only be as tall as half as long the block it’s on is (ie. 500 foot long street, 250 ft tall building). or something to that effect.
would you raise that from half as tall as the street to 3/4 as tall as the street? or just a flat “up to 400 feet anywhere” rule? only 10% taller than the the tallest of the 15 closest buildings? that would allow people itching to build now roomt o grow without getting crazy tall but allow later developers a chance to get even taller while still respecting the landscape.
how could DC preserve it’s character while allowing taller buildings and more walkable neighborhoods?
you’ve said the same generalities a million times but you never say exactly what the code should change to. i mean, come on. get for real on this if you want something to happen instead of whining.
June 26th, 2009 at 1:02 pm
Max building height in Washington is equal to the width of the right of way of the building’s facing plus 20 feet. 90′ Street right of way = 110′ Building.
June 26th, 2009 at 1:03 pm
Excellent point. Scattered around New Jersey, you do find the occasional sky scraper. It’s usually surrounded by a whole lot of nothing – not residences, very rarely a commercial district. Usually it’s right off the highway. (One such example) There’s nothing urban or walkable about them – so in my mind I can’t figure out why they built it as opposed to a more traditional office park.
June 26th, 2009 at 1:07 pm
But the only way to fit more stuff into Downtown Washington would be to either pave over the National Mall (bad idea) or else build some taller buildings.
Yes, but a lot of people do not want that. Some people don’t want more stuff inside DC centre. The fact that DC has the ordinances it has right now, means that it feels like a sort of fairly big town, rather than an anonymous city. I know people who would never agree to have DC become like Manhattan.
Why bother? Width of the right of way of the building’s facing plus 20 feet is very sensible in my mind.
June 26th, 2009 at 1:10 pm
There is the proportionality argument; that, you want building heights to be in proportion, and harmony, with its surroundings. And the way to do that is measure it against street frontage (i.e., size of the plaza and sidewalk) and boulevard width.
I think a very sensible ordinance would be for building height to maximally equal exactly boulevard width plus frontage. This would give an incentive to create larger frontages, and give the architectural structure of the city a more Neoclassical, organized, harmonious feel.
June 26th, 2009 at 1:14 pm
By the way, I am perfectly willing to trade a narrower street for a wider frontage. The lack of frontage in American city architecture is appalling.
June 26th, 2009 at 1:15 pm
@Eric – I know the buildings you are talking about. The only reason I think they may have built a tower versus campus might be the view you get on the upper floors. In much of Northern NJ, including Paramus, you’ll get the Manhattan skyline. May be more saleable than views of parking garages and other low level building.
June 26th, 2009 at 1:17 pm
Sorry, guess I was wrong. Apparently street width referred to the “visual width of the street, as measured from building face to building face,” so that includes frontage.
Much ado over nothing.
I still have my doubts about the extra 20 feet, however.
June 26th, 2009 at 1:28 pm
Myles,
“Frontage” is generally used, at least in this country, to mean the width of the lot or building along the street, not the distance from the building front to the street. That’s usually called “front setback” or “front yard setback.”
June 26th, 2009 at 1:32 pm
And even if you have tall buildings interspersed by wide roads and parking garages, you’re still saving on heating and cooling energy, so it’s still a marginal improvement over lower buildings.
June 26th, 2009 at 1:32 pm
As usual when Matt brings this up, I will note that holding aside external factors, past a certain pretty low point, building taller is LESS environmentally friendly per usable square foot. Structures have to be beefed up (and steel and concrete are not necessarily the most environmentally-friendly materials around), HVAC has to be beefed up, more and more floor space is lost to elevator stacks, and so on.
Now of course external factors such as the one Matt mentions–public transportation–also matter (but as an aside, I would note that since area goes up with the square of distance, the increased average distance from a given public transportation node only goes down with the square root of an increase in allowed height). But that just means the question of the optimal building height from an environmental standpoint becomes one of balancing external versus internal environmental factors.
And I have yet to see Matt even acknowledge the need to perform such a balance, let alone prove that the balance is in favor of building taller in Downtown DC. Indeed, for all we know buildings in Downtown DC are already too tall, not too short, from an environmental perspective.
June 26th, 2009 at 1:39 pm
Less environmentally friendly than what? Clearing some woods for single-story buildings?
It’s not a balancing act, it’s just accounting. Everything, including external effects, needs to be tallied, and that tally will always favor increasing density in a transit-oriented area over greenfield development and sprawl.
June 26th, 2009 at 1:43 pm
I think what Miles refers to in #7 is what is known as “wide, generous plazas” in US office architecture. A 1970s mis-innovation which did tremendous damage to the usability of downtown Chicago among other places. Cf William Whyte.
June 26th, 2009 at 1:45 pm
I like how Matt’s example of the lack of a tie between density and tallness is of tall, not dense places.
This elides the rather clear issue of very dense places without tall buildings. For example, Paris, without many tall buildings within the city proper, has a population density that is nearly the same as Manhattan.
In terms of DC, I’m not sure I understand the basic issue here. Building taller buildings in the city center would actually reduce capacity in the short run, as it would have to involve closing down buildings that are currently operating, given that, as Matt says, it’s already pretty built up around there. Meanwhile, there’s Arlington, which is well served by public transportation and already has tall buildings. You also have what are essentially blighted, undeveloped areas that are quite close to the central part of the city. Take a walk up South Capitol Street from Nationals Stadium to the Capitol South Metro – there’s basically nothing there, and it could easily be developed. The New York Avenue area (where, if I recall correctly, Matt lives) is in the midst of what appeared to be on my last visit to DC this past weekend an enormous amount of development. Neither of those areas is at all far from the central part of the city. Why not develop these areas rather than building taller buildings on K Street?
June 26th, 2009 at 1:51 pm
11 and 12 are directly contradictory regarding heating cost per (square, cubic) foot of building as a function of building height. Evidence?
I would note that since area goes up with the square of distance, the increased average distance from a given public transportation node only goes down with the square root of an increase in allowed height
True, but irrelevant. The *average* distance doesn’t matter because all the people with sufficiently long distances from transit are driving instead. The important fact is the number of people who use transit, which is directly proportional to the number within a cutoff distance from a transit node. (The cutoff distance varies from commuter to commuter, but if you assume random allocation, this doesn’t matter.) That, in turn, is directly proportional to floor-square-feet per land-square-foot, which is very nearly the same as max building height. (Assuming, of course, that the transit system can bear the increased traffic or be upgraded to do so.)
That is not counting parking. If taller buildings don’t also come with deeper underground parking garages, then the resulting difficulty of parking affects people’s drive vs. transit cutoffs, potentially pushing even more people into the transit column, and eventually you’re New York or Tokyo.
June 26th, 2009 at 1:53 pm
Less environmentally friendly than what?
The same square footage provided in multiple smaller buildings.
Everything, including external effects, needs to be tallied, and that tally will always favor increasing density in a transit-oriented area over greenfield development and sprawl.
But that is a false dichotomy in this case. Downtown DC even with the height restriction is hardly a case of “sprawl”, and easily has enough density already to support comprehensive transit. And we know that because it does support comprehensive transit. Meanwhile, lots of DC is not yet built to the relevant height–in fact only a small fraction is.
So, the choice is not necessarily building up in Downtown DC or building out in West Virginia (or wherever). The choice could be relaxing the height limits and building up in the existing Downtown DC footprint, or building to the same height but in a bit more of the District.
And since expanding the footprint bit in DC would still be making use of the District’s dense public transportation system, it really is not at all clear that approach is worse for the environment than building up within the footprint of the existing office buildings. At a minimum, this can’t be addressed a priori: you need to run some numbers to figure out where the balance lies.
June 26th, 2009 at 1:57 pm
Oops, I meant to say heating *and air conditioning* costs in my first paragraph. Obviously in DC the latter is more significant.
June 26th, 2009 at 2:03 pm
It’s worth remembering that skyscrapers can’t be built just anywhere. Local geology has to be able to support it.
I don’t know the situation in DC, it sounds like the height limitations there are arbitrary, but it’s possible that there’s a real issue behind it.
June 26th, 2009 at 2:08 pm
11 and 12 are directly contradictory regarding heating cost per (square, cubic) foot of building as a function of building height.
Not exactly. You do get HVAC efficiencies initially as you move from lots of small single-story buildings to one multi-story building. But then as you keep building up, the marginal efficiency gains decrease, and eventually turn negative, and eventually you reach the point such that you would be better off with the same square footage in two lower buildings. Therefore, there is going to be some optimal height (which depends on all sort of factors in any given case) when it comes to HVAC efficiency, such that above or below this point you are going to be less efficient.
The important fact is the number of people who use transit, which is directly proportional to the number within a cutoff distance from a transit node. . . That, in turn, is directly proportional to floor-square-feet per land-square-foot
No, that is where you go wrong. Take a very simplified model, with a single public transportation node in the middle of a circular development area. As usable square feet per land area goes down, you have to draw a circle with a wider and wider radius around this node to capture the same usable square footage. But that radius is only going up with the square root of the necessary increase in area.
In other words, what you are implicitly doing is keeping the area and linear distances fixed, and then varying the building height. But that means you are actually varying the total square footage as well. If you keep square footage fixed, and then vary building height, the area goes up with building height, but the linear distance only goes up with the square root of building height.
That said, I very much agree with your threshold notion. But I would again asset there is prima facie evidence that Downtown DC is already well inside the relevant threshold, because it supports a robust public transit system for commuters already.
June 26th, 2009 at 2:13 pm
Again with the height limits! I agree that the only way to get more commercial density downtown is by going up, but perhaps DC should look into getting more centers and nodes scattered about the city. By eliminating DC’s strict monolithic zoning and allowing mid-rise buildings elsewhere, DC could get more density in the large areas of suburban density in NW and SE. A lot of the reason for the clustering of office buildings downtown has to do with the way land is allocated and regulated. Loosen up the restrictions and watch Wisconsin Avenue develop.
You say that it’s the best place in DC due to connectivity, which is true, so new rapid transit might be needed to make other areas viable. Sure, building new transit lines is a long-term venture, but so is permanently altering the architectural character and laws of the city. It’s fun to speculate about that and argue online about zoning, but it’s not much good if the city government doesn’t have a plan. No plans for the metro, no plans for the outer city, just political inertia.
I wrote something about this in response to one of your earlier posts about this, same idea as above, just longer.
June 26th, 2009 at 2:17 pm
I think what Miles refers to in #7 is what is known as “wide, generous plazas” in US office architecture. A 1970s mis-innovation which did tremendous damage to the usability of downtown Chicago among other places.
They did not do it correctly, or that is at least my experience when I saw Chicago. Proper urban design, with grand Neoclassical scale, would resemble something like one of the great European capitals, or what Abu Dhabi (not Dubai) is doing right now. I have seen no American city parallel the Corniche.
One of the lessons from Haussmann is that to get have a continuous, uninterrupted urban fabric, one needs a continues, uninterrupted block-sized street facade. I don’t think any American city achieved that, or even close to it.
A lot of the tragedies of bad urban design stem from the silliness of early twentieth-century and mid-century modernism. A lot of Modernist buildings, and urban design, were simply vomit-worthy.
Postmodernism in urban architecture, in a way, represents a return to Haussmann.
I don’t actually oppose tall buildings per se; London, for example, has done an admirable job of it. What I do oppose is a lack of thought, and a lack of appreciation for the great role of architecture in the public consciousness, that seems to be the case in American urban design, which ranges from the somewhat unlikeable (New York City) to the awful.
Aside from Washington, DC, few other cities, if any, have been built on a radial axis. Which is regrettable, because a radial axis, of sorts (even a quadrilateral) is the only way you can build an architecturally sound city, and one worthy of human accomplishments.
Is there any road in America as great as the Parisian boulevards, or even the Chang’an in Beijing, or even the Sheikh Zayed? It’s unfortunate and unlikeable.
June 26th, 2009 at 2:22 pm
Anyone else find it odd that Myles was demanding large setbacks and is now praising Paris? Sure, around the museums, some government buildings, and some other major tourist attractions, Paris has big open spaces. But so does DC. And then when you get to the actual working commercial areas in Central Paris, the setbacks tend to be quite small. Just like in DC.
June 26th, 2009 at 2:22 pm
Ironically, the last great act of urban design was the Karl-Marx-Allee in communist Berlin.
June 26th, 2009 at 2:24 pm
Also, in regard to infrastructure costs (not just heating), the buildings get much more expensive to operate because of the energy needed to deliver water or air in pipes, and move people in elevators. The radical opinion these days is a maximum height of 7 stories, which isn’t necessarily a bad idea.
The cost of materials is less important than the energy costs of a commercial building over the lifetime of the building. If we’re talking about structure, then much, much less, since most skyscrapers are built to last well over 100 years.
June 26th, 2009 at 2:28 pm
> Also, in regard to infrastructure costs (not just
> heating), the buildings get much more expensive to
> operate because of the energy needed to deliver
> water or air in pipes, and move people in elevators.
> The radical opinion these days is a maximum height
> of 7 stories, which isn’t necessarily a bad idea.
**7 stories**? I would have to see some pretty detailed calcs to support that. The last detailed analysis I read was back in the 1990s, but that one showed that skyscraper was the most efficient housing method by far until you hit 60-70 stories.
June 26th, 2009 at 2:33 pm
Do both.
But there is no demand to build ten stories of commercial space in most of the district – just in the downtown. It might be possible to add downtown-scale buildings at the fringe of the existing downtown, which will be functionally part of downtown, and be in demand like downtown, thereby diverting development that would otherwise have been in a greenfield office park off a highway.
However, it won’t be possible to divert that development to a block near the Anacostia station, no matter what you set the height limit at.
There’s going to be a geographic limit to the area of downtown. Perhaps it can be bigger than it is now, but probably not by much. At a certain point, downtown will only be able to grow up. This is not because of a lack of transit capacity or even distance to transit stations, but because walking proximity to the established core downtown is so important.
June 26th, 2009 at 2:35 pm
One of the lessons from Haussmann is that to get have a continuous, uninterrupted urban fabric, one needs a continues, uninterrupted block-sized street facade. I don’t think any American city achieved that, or even close to it.
This is sort of true. Small towns with a rhythm of houses and human proportion have plenty good urban fabric. In cities, though, I agree, a continuous frontage of a block creates a more coherent streetscape. It’s important that the buildings themselves be small, not just one giant, overarticulated building like Federal Triangle.
Aside from Washington, DC, few other cities, if any, have been built on a radial axis. Which is regrettable, because a radial axis, of sorts (even a quadrilateral) is the only way you can build an architecturally sound city, and one worthy of human accomplishments.
Absolute nonsense.
June 26th, 2009 at 2:38 pm
Myles,
It is precisely the front setbacks you call for – leaving plazas in front in order to build higher – that has prevented many American urban districts from achieving such an uninterrupted block. It is often the plazas themselves that interrupt the block.
Boston is the most architecturally-sound major city in America, and it’s not built on a radial axis pattern.
June 26th, 2009 at 2:51 pm
There’s going to be a geographic limit to the area of downtown. Perhaps it can be bigger than it is now, but probably not by much. At a certain point, downtown will only be able to grow up. This is not because of a lack of transit capacity or even distance to transit stations, but because walking proximity to the established core downtown is so important.
Well, now you are introducing what is at least in part a non-environmental consideration (one which, I might note, again only goes up with the square root of a height reduction). In general, we know that there are economic reasons to provide very tall buildings in some circumstances (we know this because when economic considerations are the only significant issue, it happens). However, it could well be that this is creating negative environmental externalities, and we might want to regulate to account for such externalities.
In any event, please note I am not attempting to prejudge this issue with respect to DC. I’m just pointing out that you can’t know for sure whether or not relaxing the height restriction in DC would be good for the environment without first doing some serious numerical work. In other words, rather than guessing at the outcome, we would need to do a real study.
June 26th, 2009 at 2:51 pm
Hey! I can see my house! ok.. apartment….
June 26th, 2009 at 3:10 pm
This may be purely selfish, but anyway: Given that, into the foreseeable future, the D.C. Metro won’t receive the levels of funding needed to significantly increase trains and infrastructure, I’d rather not have more people cramming into trains and trying to get into downtown every morning. The two lines I’ve used on a regular basis (Red in from Silver Spring and Orange in from Virginia) are already overfilled.
June 26th, 2009 at 3:21 pm
**7 stories**? I would have to see some pretty detailed calcs to support that. The last detailed analysis I read was back in the 1990s, but that one showed that skyscraper was the most efficient housing method by far until you hit 60-70 stories.
Haha, mostly true. 70 stories is generally regarded as being the level where the cost-effectiveness of a skyscraper stops being positive. The 7 stories critique is that extreme height reduces the grain of the city, making it more isolating and more out of touch with the human sense of scale. The term Leon Krier uses is “vertical culs-de-sac.” You lose the interconnectivity of a building as a partof a city, just like you do in a suburb. I suppose you could try to get it back with that whole Unité de Habitation thing, but not too many of those get built in conventional development.
Also, it’s pretty much the most you can expect someone to walk up to their apartment, and since taking
When I said radical, I meant it.
June 26th, 2009 at 3:26 pm
Regarding comment 19 by MR Joel
MR Joel I would defintly agree with you on that. Washington DC was built on swampland.And even in some of it’s suburbs they still have problems with this.I seem to recall there being problems in the newer parts of Greenbelt [ a DC suburb].
For what it’s worth ,I happen to like how DC looks.Especially the victorian style rowhouses.But That’s just my opinion.Mr. Yglesias seems to like tall buildings.There’s nothing wrong with that.
But in the 20 years that i lived outside of DC [i lived in Greenbelt] ,I never met anyone from DC ,or elsewhere , that thought that the buildings should be higher.
June 26th, 2009 at 3:29 pm
It’s important that the buildings themselves be small, not just one giant, overarticulated building like Federal Triangle.
No. If the building occupies one, entire block, then it could be considered appropriate. This is the case in London.
Boston is the most architecturally-sound major city in America, and it’s not built on a radial axis pattern.
It is indeed. However, it is not a template for great metropoles, because it isn’t a great metropole.
June 26th, 2009 at 3:31 pm
I’m not aware of any hard-and-fast rule for optimal height from an environmental perspective–as I recall, it depends on too many factors. For example, I believe it is sensitive to whether heat retention or heat exhaustion ends up being a bigger problem given the yearly temperature cycle in the relevant locale (taller buildings tending to retain more heat of course).
That said, is that 60-70 floors estimate an environmental assessment, or a cost to developers/dwellers assessment? Because again, part of the problem is that the two assessments could depart due to externalities, potentially quite radically in some cases.
June 26th, 2009 at 3:31 pm
The difficulty comes when you are trying to design a great building with only one exterior face, which is near impossible to do well while simultaneously making it architecturally worthy.
June 26th, 2009 at 3:39 pm
On another note, Matt ought to spend more time exploring thought-provoking subjects like urban design and architecture, and less discussing the mundane minutiae of social legislation.
June 26th, 2009 at 4:09 pm
(first Chris, not second chris)
To clarify what I said earlier, since my grammar was unintelligible (hadn’t had enough coffee at that time) the height is determined by the right of way of the street it faces plus 20 feet.
That’s why, for example, on the K Street Corridor at the bottom half of the Golden Triangle, all corner buildings have K Street addresses. K Street has a much wider right of way than the cross streets do so they can build higher. A corner building could just as easily be addressed 18th or 19th Street, but the right of way for those streets is much less, so the building could not be built as high.
June 26th, 2009 at 4:13 pm
I love the implied optimism of this post — that the recession will end someday and that we will go back to building!
Lovely idea.
June 26th, 2009 at 4:50 pm
> That said, is that 60-70 floors estimate an environmental
> assessment, or a cost to developers/dwellers assessment?
> Because again, part of the problem is that the two
> assessments could depart due to externalities, potentially
> quite radically in some cases.
The problem tends to be the vast underestimation of externalities in the suburban (or lower-height urban) case. Yeah, it takes some additional piping and some juice for the pumps and elevators to operate a highrise, but that is dwarfed by, e.g. a satellite sewage lift station necessary to service a small office park with less usable sq ft than the skyscraper. Electricity, water, sewerage: all are far more efficient in larger quantities.
June 26th, 2009 at 4:53 pm
> Aside from Washington, DC, few other cities, if
> any, have been built on a radial axis. Which is
> regrettable, because a radial axis, of sorts
> (even a quadrilateral) is the only way you can
> build an architecturally sound city, and one
> worthy of human accomplishments.
Why, exactly? What is your definition of “architecturally sound”? Neoclassical architects of the 1800s loved radial layouts (esp in the US after Burnham), but I personally don’t see anything inherently superior about them – much less “the only way you can build a city … worthy of human accomplishments”. That’s one heck of a statement and (per Gardner) requires one heck of a corresponding proof.
June 26th, 2009 at 5:24 pm
With cities having such different characters and extents, it can be difficult to settle on a standard of comparison. A city like Phoenix or Dallas stretches its city limits far out into the suburbs, while the cities of Cambridge, Everett, Quincy, Somerville, etc. are independent of Boston, while in other cities, they would be neighborhoods. If you lay downtown Houston over downtown Boston, Houston’s city limits would stretch to Providence and Worcester.
I find that the most useful metric for comparing urban areas is the market. Boston is the 6th largest media market in America. That’s a pretty major metropole.
June 26th, 2009 at 5:25 pm
pete from balitimore,
Yglesias’s proposal wouldn’t allow the construction of “tall buildings” where there are currently Victorian-style row houses. It would allow the construction of “even taller buildings” in locations that currently have tall buildings.
June 26th, 2009 at 5:46 pm
The problem tends to be the vast underestimation of externalities in the suburban (or lower-height urban) case.
Are you sure those are the same cases? For example, how does the sewage system actually work in Downtown DC? Are there really lots of sewage pumping stations all over the place because the buildings are limited in height?
June 26th, 2009 at 7:05 pm
Neoclassical architects of the 1800s loved radial layouts (esp in the US after Burnham)
Spot on. I am a Neoclassicist, minus the Palladian, myself in the aggregate, urban-planning sense. For individual buildings I tend toward the neo-Baroque.
June 26th, 2009 at 7:07 pm
but I personally don’t see anything inherently superior about them – much less “the only way you can build a city … worthy of human accomplishments”.
American cities lack the certain grandeur, and splendour, of great European capitals like Paris and London. A part of the problem is in the shabby and provincial thinking when it comes to layout.
June 26th, 2009 at 7:12 pm
A city like Phoenix or Dallas stretches its city limits far out into the suburbs, while the cities of Cambridge, Everett, Quincy, Somerville, etc. are independent of Boston, while in other cities, they would be neighborhoods.
That’s not quite accurate. The Boston market is indeed very large, but it doesn’t really serve as metropole in the same way as, say, New York serves as metropole to Long Island.
If I remember correctly, the Cape is in the Boston market. So is Providence. So is Connecticut past a certain point. But those people, they don’t go to Boston regularly. It’s not like if I live in Providence, I go to Boston for weekend shopping at Neiman’s.
June 26th, 2009 at 8:43 pm
American cities lack the certain grandeur, and splendour, of great European capitals like Paris and London. A part of the problem is in the shabby and provincial thinking when it comes to layout.
I wouldn’t argue with that, but the idea that only radial cities can demonstrate grandeur in layout is simply untrue.
Also, Providence is its own media market, Hartford is a media market, and much of CT is in the New York media market.
June 30th, 2009 at 7:52 pm
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