KWCIMBY, or Kowloon Walled City in My Backyard, is a refrain used by some YIMBYs to make it clear that we favor high density and not the missing middle self-compromise. This is not about the literal KWC, which was poor and hideously overcrowded – the floor area ratio from photos looks like it averaged around 8 counting open space, so the density meant it had maybe 6.5 square meters of built-up space per capita. Rather, it’s about the concept of going as high as possible, using higher floor area ratios (the Upper East and West Sides of New York have 12 residential FAR on the avenues) and generous first-world urban living arrangements to create high urban density. This post is about how it might look.

One possible built form is this:

This is 100*100 meter blocks, with 20-meter wide streets; this is not intended to be a city for cars, but at high residential density it’s useful to widen the streets somewhat to provide ample walking and cycling space and to allow very tall buildings while keeping the building height-to-street width ratio reasonable. The buildings are in dark gray, in euroblock form with the courtyards denoted in green.

Internal building layout

The building is 20-meter thick, which is wider than normal for Berlin euroblocks but compensates by not having internal wings, so that the apartments’ area-to-window frontage ratio is about 9 meters, which figure exists in Berlin and Paris. The inner corners feature elevator lobbies, depicted as 10*10 meters, but they can safely be made smaller. Let’s Go LA’s post about high-rise floorplates in Los Angeles, Seattle, and Vancouver shows some examples of elevator lobbies with scissor stairs and some extra corridor space at 63 m^2, and here scissor stairs aren’t needed for fire safety because each of the corners is redundant with the other three.

The footprint of the built-up area is 4,800 m^2. Of that, 722 are circulation space, or 15%; this is not amazing, and it’s possible to do better by having somewhat narrower corridors than 2 meters and somewhat smaller elevator lobbies, reaching about 90% efficiency instead of 85%. If the lobbies remain 10*10, they may include additional functions, such as trash rooms with chutes, or maybe laundry rooms in cities where it’s not normal for people to own washing machines.

The apartment floor plates are forced to be rectangular and not terribly interesting, with rooms opening to windows. My presumption is that each window space is 2.5 meters wide, so a bedroom or an office occupies one window, a living room one to two windows, and unusually large bedroom two. Kitchens can take a full window or be in an open plan with the living room. Bathrooms don’t normally get window space, and the depth of the apartment is such that every bedroom can have an attached bathroom.

An austere apartment is around one window per person, or around 22.5 m^2 per person; a spacious one is around two per person if it’s a family, or 45 m^2 per person, or even three for a single person who wants a guestroom. 45 is normal by Northern European standards and if anything on the low side by American ones, but it’s in practice degressive in household size and American NIMBYism is such that families rarely live in big cities, a household in which half the people are children and therefore do not work not really being able to compete for scarce urban land with a household in which all members work. If there’s abundant space, then middle-class families will take 8-window, 180 m^2 apartments in such buildings, and working-class ones will take 4-window apartments.

So what’s the density?

The courtyard is fully enclosed, so the limit to how much sunlight the bottom apartments get is the ratio of the building’s height to the courtyard width, which is 40 m. In Berlin and Paris one finds many euroblocks with wings such that the ratio of the height to the courtyard width is around 1.8, and a fair number in the 2-2.5 range. Our building can have 25-30 floors, or a height of 75-90 meters, while respecting this ratio. This is a building height-to-street width ratio of about 4, which is not common in Paris and Berlin (I see a bunch of 2 but not 4), but does exist in central residential areas in Tokyo and I think also Taipei, and in commercial ones in New York and London.

25 floors times a little more than 4,000 net m^2 per floor is 102,000 net m^2. If it’s 30 floors, make it 122,000. Figure exactly 45 net m^2 per person, with the more austere floor plans canceling out with vacant apartments, with empty nester apartments, and with three-window, 67.5 m^2 singles. This is 2,265 people per hectare at 25 floors, or 2,718 at 30 floors. Per km^2, this is 226,500, or 271,800 at 30 floors.

The vast majority of built-up space is residential, but with buildings this tall, the ground floor is presumably retail. One trick that can be done is to have retail, such as a supermarket, occupy the entire 80*80 block not including the street, and then put the courtyard on the roof of the supermarket, allowing one or two more residential floors.

A percentage of the buildings is entirely non-residential, such as schools, hospitals, office buildings, and emergency services. Schools are, in British standards, 5.13 m^2/primary student (p. 9), 7.81 m^2/secondary student (p. 10), and 9.28 m^2/16+ student (p. 11), all assuming maximum school size. Schools can be bigger than the maximum assumed in the UK – New York’s Specialized High Schools are each around 1,000 students per grade, and Singapore’s secondary schools and junior colleges have around 700-800 per grade. A 12-story euroblock will fit 6 grades generously at 1,000 students per grade, which is compatible with a base population of around 80,000 at equilibrium, so a square kilometer with 200,000 people needs 2.5 primary and 2.5 secondary schools, or 5 out of 100 blocks used for non-residential purposes. This is the biggest nonresidential, noncommercial use, I believe – everything else is probably 1 building out of 100 each, and maybe a handful of blocks can be parks, with a total of 10 blocks in 100 neither residential nor commercial.

Non-euroblock forms

Instead of euroblocks, it’s possible to use building forms without internal courtyards. For example, one can break each 100*100 block into 50*50 blocks, still with 20 m street width, giving 30*30 buildings:

Instead of 4,800 m^2 of built-up area per hectare one gets 3,600, but the floor plate efficiency, again stolen from the standards in the Let’s Go LA post (this time, with scissor stairs), is more than 90%, and the building sizes are completely standard for high-rises in Tel Aviv or Vancouver. With no internal courtyards, one can get 30 floors or so, which at 45 m^2/person is 222,900 people/residential km^2, or maybe a little less because of ground floor retail.

There’s also the modernist form of linear buildings, typical of communist-era blocks in Eastern Europe, and some postwar public housing projects in the Western Bloc, especially France (but the United States preferred cruciform buildings).

The street width in the direction parallel to the building widens, which in cities that retrofit such forms can be seen as generous setbacks, allowing the same amount of light to reach the lower floors with taller buildings. The overall built up area is 3,200 m^2 per floor, of which 2,864 is net. If we keep to a 4-to-1 height-to-street width ratio we can reach 40 floors now, which is 254,600 people per residential km^2.

The streets in this case can be set up to create long parallel blocks, or to do the opposite, alternating the orientation of the buildings to break the wind. And of course, all building forms can be mixed, so one block is a euroblock, the next is four 30*30 buildings, the one after is two linear blocks, and perhaps the one next to that is two 30*30s and a linear block.

Where is this appropriate?

Construction costs for buildings are not entirely linear in building height. The reason one would build 30-story buildings one after the other rather than single-story houses is that the area has high demand. So your town of 200,000 people has no chance of fitting in one km^2 with such buildings – nobody needs such a built form, even if there are no cars, because if there are no cars then every street is automatically a bike lane and then the town’s range is maybe 10 kilometers and it doesn’t really need multistory apartments except maybe right near the center.

So this is a way of organizing large cities. The use of buildings that are not just tall but also big reinforces the size of the city as well – a city of 100 buildings is a city with severe monopoly problems among developers and landlords, whereas one with 5,000 is one where people are upset at large developers but there is meaningful competition for tenants. Cities that are large but not hug would presumably use the 30*30 building form in preference to the euroblock just because it can be done by smaller developers.

In practice, it’s also a way of organizing large, growing cities, or cities that will grow if development is liberalized. One doesn’t easily replace heterogeneous blocks with big buildings without a lot of demand. Tel Aviv and Vancouver have 30*30 skyscrapers because they are medium-size, high-demand cities, so any site near city center with a few small buildings can be redeveloped; of note, neither uses this building form much outside city center, except perhaps at transit-oriented development sites around designated town centers like Metrotown.

So the isotropic picture at the beginning of the post is an abstraction. In practice, there are always gradients in density, and that’s fine. Some areas get 40-story buildings, other gets smaller ones, or no redevelopment at all; that’s why, even in environments with liberalized zoning like Tokyo and Seoul, neighborhood-scale zones do not reach 200,000/km^2 at developed-world crowding levels. KWC was a unique situation, a tiny no man’s land, and even though Hong Kong is the developed world’s overcrowding capital and has tall buildings to boot, its built-up density has not recurred.

That said, KWCIMBY building forms remain valuable for urban design. City centers genuinely need more development, and while the very center of the city should mostly have offices, one doesn’t need to go too far to get to areas that are mostly residential and mostly very desirable. Tall, densely spaced buildings reaching 200,000 people/km^2 would facilitate comfortable living in the post-car city, and it’s useful to plan for them in the near future.


  1. michaelrjames

    I don’t know why anyone would want to build such a city district. One simply doesn’t need, or want, densities that high. KWC was in fact >200,000/km2. Most of it was 12 storeys with some bits up to 15-16 storeys (including ad hoc additions at the top). There’s a reason why no (legal) place approaches these densities, though interestingly the one place that does is also in Hong Kong: Union Square in West Kowloon has about 18,000 residents on 14 Ha for ≈125,000/km2. This doesn’t include transient residents such as in the Ritz-Carlton that occupies floors 102-118 of the International Commerce Centre (ICC) building, at the time the 4th tallest in the world. The site has 5,866 residential units, 2,230 hotel rooms, and 2,490 serviced apartments, so its density could be well above this estimate. Most of the residential buildings are 64 floors. Same as in Tung Chung new town which when complete would also be about 125,000/km2. But both these developments have plenty of open space. In fact Union Square is somewhat marooned like an island-fortress in the vast openness of the West Kowloon reclamation (it seems this arrangement is permanent?).

    No accident that both these HK developments are on reclaimed land and thus the pressure to use them to the max. But as I say there is no inclination to do this kind of development elsewhere. Stuyvesant Town-Peter Cooper Village has 11,0250 apartments with ≈25,000 residents, on 32 hectare at ≈78,000/km2. But it is not a functional city being totally dependent on all the normal facilities outside its walls including retail, schools, med clinics etc etc. Significant areas with those facilities included such as UWS and UES have densities of 43,800 and 42,100/km2 respectively which is matched by Paris 11th arrondissement. However I think this points to desirable densities of these latter (≈40,000/km2) to approx the Paris average of ≈25,000/km2.

    That one can squeeze much more in a given space, by going tall, is not in contention. As I keep repeating, however, there are reasons why this is hardly ever done and only under seriously exceptional circumstances. Singapore nor Tokyo (nor Seoul?) need go nowhere near these extreme densities. Clearly the urbanism of such a district would be awful. Thirty storey buildings, built to the perimeter like that, block after block would be relentlessly fatiguing to the eye and brain. It would be beyond oppressive which is why those HK developments are not of this form, but in ultra-tall with podiums and space between the towers. Likewise in China. Vancouver is not like that.
    KWC was demolished in 1984. I believe it is now a park surrounded by modern 14-15 floor residential apartments like you see here:

  2. michaelrjames

    Concerning your internal layout in Euroblock mode, afaik, there are none like that in old Paris, Berlin, Barcelona, Madrid etc. Even back in the 17th century when the typology was more or less invented by Christopher Marie for development of Ile Saint Louis, they realised that one doesn’t want long corridors like that, and equally one doesn’t want such a vast array of apartments (even if only 6-7 floors) to be open to so many residents. In general an apartment “building” is a vertical slice in general no more than two apartments wide. Today one could retain those corner elevators/stairs but without open connection of all those long corridors; the elevators serve both corridors but don’t connect them (ie. via the doors at both ends of the elevator and e-card security system; only one door can open at a time, except perhaps in fire emergency). Likewise an adjacent scissor-stairs serves both corridors but without allowing one side to access the other side (in the version where two flights–ie. one segment of steps in one direction then a 180° turn for the second segment of stairs). By this fashion all apartments can access two elevators and two stairs at the ends of their corridor but cannot move into the other parts of the building.

    Of course you are trapped into this long corridor thing because building regs require >1 elevator (and sometimes >1 stairwell) above a certain height threshold. (the 24-floor Grenfell Towers had a single staircase for its 120 apartments) That will vary but I believe it is of the order of above 8-ten floors. Below 6-8 floors you don’t need it so those corridors can be halved–and thus creating more manageable individual apartment buildings (vertically speaking), plus the big benefit of some traversant apartments in the centre (8 per floor/block). My version has max 5-6 apartments wide with the two outer edge ones being luxe traversent and the rest with only one exterior wall: two of the six =small studios, two = 1-2 bed; double this per floor, ie. two traversent big apartments, four studios, four 1-2 bed; thus max of 8 to 10 apartments per floor and up to 70 apartments per apartment building (ie. vertical slice of overall structure; ground floor=commercial or other function). This is already more than you really want to be sharing communal space; it would have a single elevator but with scissor stairs (accessed both sides of elevator). In fact in your plan I am fairly sure the authorities would want two elevators at each corner, for total of 8.

    Only in places like Soviet Russia or Communist China and in the 50s-70s project housing, do you find those awful long corridors and all the problems associated with so many people sharing/accessing the whole site and stairs and elevators.

    • wiesmann

      Maybe because of an ageing population, in Switzerland, new buildings need an elevator if there are four floors or more…

      • michaelrjames

        Fair enough. For disabled access too. I don’t know if it has filtered into anything official but there is a rethink on their use to escape fires too. They’re in the strongest and best protected core of these buildings.
        The cost of an elevator does affect the economics of height, at both the bottom and top end. I don’t imagine many 4-floor buildings get built because of this, and the maintenance cost not split enough ways. Those ultra-talls in NYC have quite small footprints and so they have to restrict the number of elevators, and they overcome the normal rules by arguing (correctly) that only one in 3 or 4 of these hyper-expensive apartments are occupied at any one time.

        • wiesmann

          Actually, there are quite a few 4 floor buildings getting built, given the prices of housing in high density areas of Switzerland (Geneva, Zürich), the cost of an elevator is not that dramatic. There are also ways to cheat a bit, as the rule seems to just apply to appartement entrances, so you often have a duplex flat on the upper floor.

    • Alon Levy

      I think two apartments per floor is a pre-Haussmannian form? I lived in these buildings in Paris, but then moved into an Haussmannian one with four, two per stairwell, each stairwell hugging an elevator. In Stockholm my building, built in 1907, was a back wing with two apartments per floor, but the street-facing building with the elevator had four per floor. In Berlin I’ve seen buildings range from two to four, but the ones with elevators tend toward four; my current one is from 2015 and has three, whereas the previous one I lived in had outdoor balcony-corridors typical of California and Japan enclosing the courtyard and something like eight apartments per floor.

      That said, the New Law elevator buildings in New York tended toward bigger buildings. Eight to 10 apartments per floor is pretty normal, in working-class areas like Washington Heights as well as middle-class ones like Yorkville and the Upper West Side. In New York, two apartments per floor is either for towers on Central Park West with big apartments and park views or for Old Law tenements.

      In my plan there should be around four elevators per corner anyway, for capacity; the designs I’m cribbing my area calculations from have three to four and have noticeably smaller elevator lobbies, but are smaller floor plates with seven to 10 apartments per floor whereas I’m assuming around 40. You can very much take this form and convert it into four separate buildings each taking one corner – you need less corridor space and get more apartment space in the middle of the block but you may need slightly larger elevator lobbies for fire redundancy.

    • yuuka

      A lot of stuff from the 70s and 80s in Singapore have one long block of apartments (~20 per floor in the building I used to live in) , but is typically subdivided with a few apartments sharing one stairwell. For some reason, they didn’t stop the elevators at every level, so in order to make climbs less torturous, there are through corridors on the levels where the elevators stop so one can switch stairwells at a level nearer to one’s apartment.

      It was only recently with the whole ageing population schtick that they went back and built elevators that stop at every floor for those apartments that didn’t have them already, but some more esoteric layouts still don’t have them.

      • michaelrjames

        @yuuka “For some reason, they didn’t stop the elevators at every level,”

        I think it was a ploy to permit lower number of elevators (and perhaps lower wear & tear) according to the usual (western) calculations: the more floors/apartments an elevator services the poorer the service for the building, ie. longer waiting times. It would have permitted in principle fewer elevators to service a higher apartment load. It’s not entirely a bad idea in that residents would much prefer to walk one flight of stairs (and can choose to walk down rather than up) than up a whole bunch of stairs. Do the elevators actually have doors for the inter-floors, ie. can be used with key-operation from the building manager, so they can be used for house moving, or heavy item delivery?

        Trivial fact: most of the elevators squeezed into those old-ish Haussmannian buildings in Paris stop at the penultimate top-floor. This is because elevator housing for the cables, pulley & motor mechanics is not allowed to sit above the roof like they do in other ‘modern’ cities. Modern elevators don’t need this.

        • yuuka

          Nope, no door at all, just a wall.

          Hence the construction people had to hack out new landings.

          • michaelrjames

            I had forgotten about this. It is from the Wiki on the notorious Pruitt-Igoe housing projects in St Louis that were built in the mid-50s and demolished in the early 70s.

            The apartments were deliberately small, with undersized kitchen appliances. “Skip-stop” elevators stopped only at the first, fourth, seventh, and tenth floors, forcing residents to use stairs in an attempt to lessen congestion. The same “anchor floors” were equipped with large communal corridors, laundry rooms, communal rooms and garbage chutes. The stairwells and corridors attracted muggers. Ventilation was poor, centralized air conditioning nonexistent.

            It had 33 eleven-storey buildings on 23Ha; at a planned 15,000 residents (which it never achieved, at max 60% occupancy) it would have been ≈65,000/km2. I’m just giving that for interest; I’m not saying density was the or a major issue. There were a whole host of factors in its failure, one of which were those long corridors:

            The stairwells and corridors attracted muggers, a situation exacerbated (or even caused) by the “skip-stop” elevators.[10] … When corridors were shared by 20 families and staircases by hundreds, public spaces immediately fell into disrepair.[20]

  3. Tonami Playman

    Regarding schools. How does one handle the high volume movement of students between classes. Will the 12 floor schools feature larger capacity elevators?

    I read that Shenzhen has placed a height limit 24m on schools for fire safety, cost and movement reasons. Previous schools frequently exceeded 30m in Shenzhen, but there’s been a crackdown for more robust and fireproof elevator access for school buildings that exceed the 24m limit. Most newer schools feature ramps and have 6 – 7 floors within a 24m height.

    • Eric2

      Densities like 271,800/km2 are excessive. I don’t think there is any need for cities of population ~5 million or less to have densities over 50000/km2. Even Eixample, the densest part of Barcelona, only averages 36000/km2. Even in larger cities with a demand for extreme density (NYC/London/Paris/Tokyo/Osaka, plus many third world megacities), 100,000/km2 should be sufficient. Luckily, this apartment plan can be linearly scaled down to any desired height and density (creating more sunlight for the lower floors at the same time).

      • michaelrjames


        You’ll think I’m picking on you, but it’s the things you write … !

        Even in larger cities with a demand for extreme density …

        The demand is not for density, the demand is for access. Which can be obtained by a few means, one being proximity which will drive density. Another of course would be rapid transit.
        But what is “extreme”?
        And proximity itself is very contextual. Most Americans won’t walk further than their front doors to their cars or a Uber. This is not true in Manhattan and the relatively modest walking they do–to the subway, to local shopping or schools etc, and walkup apartments–is at least one factor in why it is the thinnest American major city.

        100,000/km2 should be sufficient

        ? Isn’t that totally arbitrary. Alon could correctly respond, well why not 250,000/km2? And your list ((NYC/London/Paris/Tokyo/Osaka, plus many third world megacities) actually has only one fairly dense city. Yes, Paris. But I suppose you meant Manhattan. But you are confusing size of a city with density and it ain’t the same. Tokyo is the biggest city in the world but by no means among the densest. What it does have to compensate (partly, not entirely successfully) is rapid transit.

        Instead of arbitrary pronouncements or worse, inappropriate use of extremes, the world’s cities tell the story of human preference (or endurance under sufferance). The latter is the case for Hong Kong, and I say that as a great fan of the place (alas, probably not its future), and surely even Alon can admit that overall very high densities (arguably the highest in the world) and smaller patches of ultra-density haven’t solved the housing issue and are part of the problem not the solution; as I wrote elsewhere this is the issue that has seeded all the other discontent. (The business community has no one but themselves to blame–just a bit less greed and a bit more consideration for all their people would have kept this problem contained and increased HK’s local economy.)

        Barcelona’s Eixample is only 7.5km2 so small relative to whole cities but it is a very valuable case study. At 36,000/km2 some might claim it is an excellent case for this order of high density but actually it has always had well-known defects that are only now being addressed. It is the reason for the superblocks initiative, to reduce the car problem in that relentless street grid, and to finally correct the paucity of “people” space. I’d also note that Alon’s fantasy blocks have exactly the same defect as Cerda’s: central courtyards that are too big. (However Alon’s courtyards are far worse because they are walled in by 30-floor buildings on all sides!) In the Eixample this was what was supposed to provide more ‘open’ public space but it was too valuable as space for other things, mostly commercial and thus it all disappeared quite quickly. Inevitably this made the choice between cars versus people and Barcelona is finally making that choice. It’s almost two decades after Paris mayor Bertrand Delanöe whose election slogan (perpetuated today by his then deputy Anne Hidalgo) was “Paris for people not cars”.

        With Manhattan, it has patches of high density with UWS & UES at about 40,000/km2 but overall residential density is about 29,000/km2 (of developable land). This is why it doesn’t seem especially crowded, and the zones that appear crowded are due to agglomeration of workers or occasionally visitors/shoppers in small zones. Talk about even higher densities is unrealistic. The main housing being built are ultra-talls or very high-end like Hudson Yards (or those Richard Meier medium-rise), and neither of these add significantly to density; indeed if the trend continues, by displacing (and demolishing) existing housing they will result in a drop in density not least because a lot of the new owners are only part-time residents (not legal residents at all). I reckon Manhattan has reached its zenith and will either stabilise at current levels or in fact decline somewhat. Possibly covid will play a role, but it was bound to happen anyway. Unlike Hong Kong or Singapore or even Tokyo/Osaka, people have many other choices, not least Brooklyn! Though the same thing is happening there; Matt Damon has just bought the top few floors of Brooklyn Height’s Standish building as the borough’s most expensive apartment and I’m doubtful he will be a legal resident.

        Then there is Paris, Europe’s densest city–and not just intramuros (89km2, 2.3m residents) but also the greater city including the Petite Couronne (inner ring) with ≈7m on 760km2. At about 26,000/km2 (intramuros) it is stable because there is little potential for new housing (unless Alon gets his evil ways; he won’t so he packed up his toys and decamped to Berlin:-) which is balanced by slow gentrification (fewer, bigger existing apartments?). That is exactly the way most Parisians and, fwiw, visitors like it. The megacity continues to grow but it can easily handle that by quite gentle densification of the Petite Couronne (currently ≈7000/km2), and centres in the Grande Couronne served by the RER as distant as 40-50km out.

        This is why people like me (and Yonah Freemark, I believe) use Paris as the model–because it implements an urbanist’s dream scenario of very functional density (but nothing approaching the extremes) to support the bestest urbanism combined with highly functional rapid transit that ties it all together. NYC took lessons from Paris in the 19th century and it seriously needs to do the same in the 21st, ie. it needs to build a RER network on top of (so to speak, actually below) its subway to service human-scale (for simplicity, call it Haussmannian) residential communities.

        So, the actual evidence does not support fanciful notions of 200k/km2 or 100k/km2, and in fact tells us that even the Eixample’s 36,000/km2 is non-ideal, conditional on context. I claim Paris, Manhattan, Singapore and others demonstrate that the upper range to about 30k/km2 is as much as any city needs. It makes much more sense to densify nearby zones like Petite Couronne or Brooklyn, and as Singapore is doing, building newtowns at its periphery that are served by its “20 minute city” Metro (in any case overall Singapore density is about the same as San Francisco or Paris-Petite Couronne; the media propagates a lot of nonsense about the city state, and most of its apartment stock is medium-rise not hi-rise like HK).

        Just to repeat the lesson for you Eric, this is not just my opinion, it is not arbitrary but is evidence-based. In important ways it is Darwinian evolution–the best urbanism comes out of densities of about 7,000 up to about 30,000 per km2.

      • anonymouse

        Yes, Stuyvesant is 10 floors and has pairs of escalators going up two floors from 2-4, 3-5, 4-6, 5-7, 6-8, and 7-9. There are also two high capacity stairways, one on either side of the building, and students are in general prohibited from using elevators. I don’t recall too many circulation problems.

        • yuuka

          How do they even get from odd numbered to even numbered floors? The regular stairs?

          • Joseph

            Yes, the stairs.
            There was a little congestion on the escalators but it was never a problem.
            IIRC in addition to the high-capacity stairs there were two additional stairways on the far sides of the building.

        • Sascha Claus

          Even low-rise school buildings get elevators for disabled people, if the occasion allows. Non-disabled students are likely banned from using them everywhere they exist, otherwise they’ll spend all their break queueing in front of the elevator and always being late to class. Transport with an elevator that doesn’t take half the floor is far to lumpy to move that many students in the short time of a break.
          If you’re worrying about the poor students running up and down twelve storeys, it might be able to goup everything like 3 4-storey schools on top of each other, so that students don’t have to walk more than 3 storeys up or down between lessons.
          Another solution would be to build 3 separate schools, each 4 storeys, with 8 floors of apartments on top.

          • michaelrjames

            @Sascha “Another solution would be to build 3 separate schools, each 4 storeys, with 8 floors of apartments on top”

            I think this discussion of vertical schools demonstrates how “high-rise” just takes on a presumptive life of its own. As I keep pointing out–and people like Dr Levy who are not the least mathematically challenged should understand–building to the old Euro limit (which for simplicity I call “Haussmannian”) achieves more than adequate density and economy of space/function for almost all purposes, with the sole exception of business (and covid is changing some minds on that too, though funny enough not mine!).
            In my part of the world some inner-city schools (which are mostly the hi-end private schools sitting on extremely expensive real estate) have built new buildings in the past decade (many accessing the federal cash-splash of tens of billions to counter the GFC) that have put the assembly point on the roof–of generally 4 storey buildings. They have giant sails protecting against sun and weather, and presumably at other times the space is used for sporty things like basketball, netball etc. A great idea because it uses otherwise unused and large space, and is very pleasant too (still ‘outdoors’) for morning assembly or any assembly.

            I’ve never seen an escalator in a school but one could use high-capacity ones to take students from ground or first floor to the third or 4th floor, the way some malls and transit stations use them.

  4. Scott Feeney

    Cool thought experiment. My ideal urban form, if starting a neighborhood from scratch, would be micro-neighborhoods of between 3×3 and 5×5 city blocks, each centered around a park spanning one or two blocks. Building heights would be staggered like stadium seating away from the park, from 4-6 stories directly facing the park to 8-18 stories on the borders between these micro-neighborhoods, creating an urban room with a pleasing sense of enclosure, and a varying form that helps people navigate and remember where they are. I find that the places I’m happiest in cities often accidentally resemble this. The “border” streets with the tallest buildings would be the transit spines and have the highest concentrations of retail, while retail scattered throughout the interior of each micro-neighborhood and fronting its park would be geared to a more local set of customers.

    If you stop at 18 stories, you can build with wood, which has less embodied CO2 (Type IV-A in the 2021 IBC).

    For most US cities, though, I’ve come around to the realization that 5 stories is plenty and there isn’t much need to go higher just for density’s sake. After all, that generates plenty of density for walkability, and as authors like Alan Ehrenhalt have noted, above the fifth floor one loses any semblance of connection to street life.

    I’m skeptical of, say, Minneapolis building 20-story condo buildings. I wonder if it’s not something that is happening to work around artificial scarcities of land near higher-quality transit (so then improve transit) or of political will to build dense. On the market side of things, these projects are likely a function of developers wanting to offer views and high-rise living as a luxury amenity, which can only happen if such buildings remain relatively scarce, making them irrelevant to a serious proposal for mass housing. One just doesn’t need to go that tall when there’s so much land already developed at low density in all directions.

    My own city of San Francisco is obviously an exception to this due to its severe housing shortage, compact size, and geographical limitations of water on three sides and a mountain on the fourth. And of course you’re not American and are writing with an international perspective, so this isn’t a critique, just an observation.

    • ericson2314

      > On the market side of things, these projects are likely a function of developers wanting to offer views and high-rise living as a luxury amenity, which can only happen if such buildings remain relatively scarce, making them irrelevant to a serious proposal for mass housing.

      I think that’s absolutely correct. I think distinguishing between dense building and dense neighborhoods might cure a lot of left-NIMBYs.

    • Matthew Hutton

      The other advantage of 4-6 stories as a minimum is that you could have 2-3 storey houses next to them without them being ridiculously overlooked.

  5. Diego

    This would set the maximum population of Malé (main island) at 400k, compared to ~110k in 2014. You would need to fit some office space in there too but on the other hand in a region this close to the Equator it’s probably acceptable to have higher ratios for the building height wrt street width or courtyard size.

    So it looks like they still have a fair amount of room to grow.

    • michaelrjames


      Ha, the only reason to build to Alon’s scheme in Malé is so they can just move up a floor as the ocean rises around them and the island sinks beneath them!
      I actually have no idea how Malé exists. Where does their water (and power) come from, and where does it (waste) go to?

  6. Diego

    Now I’m wondering how you imagine to allocate street space in such a neighbourhood. I imagine that even if we’re car-free we’ll still need trucks and delivery vans. Cargo bikes are nice for personal use but they can’t scale up to supply an entire city.

    So I see:
    * 2x5m sidewalks
    * 3+1m bidirectional bike lane+buffers
    * 3m truck/van lane
    * 3m mixed use lane for loading/deliveries, bike parking, trees, benches

    The sidewalks are probably wide enough that they could be used for outdoors dining too, but I haven’t thought about what the pedestrian flow would be at such high densities. Otherwise you can try squeezing the outdoors dining in the “mixed use” lane.

    • Sascha Claus

      If it’s a residents- and delivery-only dead-end 30 km/h street, you might leave out the bike lane. Pedestrian flow might be helped by setting back the ground floor (like at Lützner/Saalf. Str., only done useful 😉 ), thus creating a wider sidewalk.
      If the buildings are lower, 5m is definitive enough for narrow outdoor dining; the remaining sidewalk space might be sufficient for higher buildings as well.

      • michaelrjames

        @Sascha Claus “Pedestrian flow might be helped by setting back the ground floor (like at Lützner/Saalf. Str., only done useful 😉 ), thus creating a wider sidewalk.”

        In fact, the better model but still in the spirit of your idea, is the use of colonnades. So, the ground floor (sometimes with its own mezzanine), which is 2x height, ≈4 to 7m, is set-back relative to the rest of the building but where the building itself is now built to the perimeter defined by the road not the pedestrian path. This actually liberates more space for the buildings. There’s plenty of examples in Italy–in fact by memory entire old city cores are like it in places like Ferrara (a beautiful walkable town) and maybe Bologna (memory fails me). But of course my fave examples are in … you guessed it, Paris. Rue de Rivoli is a very prominent case. It provides cover for both pedestrians and plenty of space for quasi-outdoor dining (the best; fully outdoor dining in any weather hot or cold is not ideal) while still providing plenty enough natural light and ventilation due to the double-height; well as long as the buildings are Haussmannian and not hulking giants like Alon wants. Another prominent example is Place des Voges. Similar to Piazza San Marco in Venice, though on a square rather than street. Likewise Plaza Mayor, Madrid.
        Paris adopted it because it likes to pretend it is a Mediterranean city, however it still works and provides big advantages even if it is more obvious in much hotter, sunnier places like Italy and Spain.

        • Sascha Claus

          I don’t particularly remember that many colonnades in Bologna, only a one or two. But Torino has the whole core littered with them, and even marked the colonnades on the touristic, free city map distributed by hotels.

          • michaelrjames

            I only stopped briefly in Bologna on my way to Ferrara (not far north) so can’t recall (or perhaps distinguish memories from Ferrara). But I think it is a style of the Emilia-Romagna region. Wiki says Bologna is “Famous for its towers, churches and lengthy porticoes” –in which “lengthy porticoes” means colonnades–so it seems to be the case. It is possibly less obvious because the city has grown so much in modern times compared to Ferrara which is much smaller and almost entirely intact inside its ancient walls.

            As an aside, Ferrara was one of the very few Italian cities that I felt I could have lived in. A bit small but extremely civilised and calm due to a lot of the ancient centre being pedestrianised and with a network of those colonnades. I find most Italian cities and even towns to be too busy and intrusive in that Italian fashion (lack of respect for private space) and tourist hordes, yet poor provision of public services. Ferrara was bliss. It is one of those cities that claims (one of) the first med school in the world which has turned into a big modern research hospital–so even jobs for the likes of me (and the reason I was visiting). Psst, so don’t tell anyone, let Bologna keep the glory and the crowds!

        • Diego

          These two-story colonnades are common in other cities too! In central Athens they work wonders in providing breathing room in narrow streets. In Rio de Janeiro they provide much welcome shade.

      • Diego

        At 200k people per km2, I imagine the demand for deliveries would be very high. Plus, even the through streets here are 20m wide. So I’d imagine they’d all be seeing plenty of truck and van traffic, hence the need to separate the bike lanes. I would imagine an insanely high density of cyclists too.

        And I agree on the colonnades, they’re a great solution. Even if they’re set back quite a lot from the street, there is plenty of developable commercial real estate if you allow 100% lot coverage on the ground floor.

        (I know this is more science fiction than real life, but it’s fun to imagine.)

  7. Martin Kolk

    I think comparisons with Tokyo and Taipei are interesting but show the limits of assuming a Euro block-structure. Measures such as building height-to-street ratios make sense in a block system, but less system in the Asian/Japanese planning system with large gridded square roads, withing them nesting mazes of lanes (often several hierarchies of progressively smaller classes of lanes also).

    Cities with nested lanes (Taipei is a very good example) have very small lanes where the building height-to-street ratio is very high, though they still feel very intimate, as they are only wide enough for a single car, and carry mostly scooter/bike/pedestrian traffic. Such cities have larger roads with pretty low building height-to-street ratios (also in a western perspective) as these roads are wide and serve as main transport corridors. Parks and green space are arvailbe on an ad-hoc basis and are neither block-sized, nor within courtyards. I think in general it is a much better model for high density. It also allows a very human scale when you walk within lanes, while still allowing very high density, and shields residential areas from to much traffic. Perhaps not an option for the highest global CBD density though (e.g. FAR>8). That is probably easiest achieved simply by tall free-standing towers (e.g. HK).

    • Joseph Breed

      I really like Taipei’s urban form overall, and prefer it to anything I’ve seen so far. I think there are a few issues with it however. For one, a lot of apartments get no sunlight, which doesn’t bother me (and may not be a problem for many Taiwanese), but seems to be a big issue for many other people. Also the density isn’t all that high, with Yonghe reaching 40,000/km2 and Taipei’s densest district only going up to 25k (though that doesn’t include students and unregistered residents). And even though Yonghe isn’t wildly dense, it’s still a difficult place to live, what with all the vehicles and the lack of green.
      On the other hand there’s plenty of room for taller construction on Taipei’s boulevards. The Taipei Main Station area would be a perfect location for a high-density CBD, and Xinyi is actually not very dense given all the massive setbacks, wide streets, and soulless plazas. And of course if they actually tried to discourage driving they could convert parking lots into parks.

      • Martin Kolk

        I also think the overall urban form is very nice as well as functional. I think all the river areas compensate quite well for a lot of the lack of green space (so does of course the mountains at a larger scale). Of course, in some spots, a few larger parks would be welcome, but in for example Yonghe the riverfront is only a few hundred meters away. As you say there are plenty of available ways of improving various traffic aspects, but the best part of the urban structure is how well it insulates smaller lanes (which is most of the city), from the traffic chaos, while still feeling very vibrant nearly everywhere.

        I think there is little need or reason to want or expect density above 30,000/km2 in any high-income context. It is reasonable to have isolated spots with very all residential buildings close to very good transit that are higher than that, but as a goal for very large city districts, I think 30,000/km2 is fine. It seems a reasonable aspirational limit and I see very few OECD cities that would benefit from density higher than Taipei. I assume the low density in Taipei also partly is reflected by the large areas that cannot be constructed due to flooding, as well as all the hills. I also agree that Xinyi is pretty bad urban planning (which is maybe a bad omen for the city).

  8. seangillis78

    This proposal would seem to be somewhere between Le Corbusier and Bjerke Ingalls courtyard / tower combos.

    I would echo other posters: why such high, high density? To borrow David Levinson’s thoughts on the (potential) changes coming to urban form and urban economies: “Thanks to technology (rail, elevators, air conditioning, etc) we now can support cities that would have been unthinkably large two centuries ago. But thanks to other technology (broadband internet, wireless, computers, software) we don’t have to.”

  9. Matthew A da Silva

    Fun thought experiment, but from an urban design perspective this falls short. Someone like Marco Chitti could go into a lot more detail than me, but the long-story short is that there are no nodes or landmarks for people to orient themselves around for the purposes of navigation, spatial awareness, and community cohesion. There are no natural central gathering places in this design. The private courtyards are no substitute for public plazas, parks, promenades and green spaces.

    From an urban economics perspective: the main thing I notice is the lack of a density gradient. Presumably some parts of this hypothetical city are more desirable/in demand than others, and there is no reflection of that in distribution of uses or density. For that reason I am not sure this would ever work out as intended in real life.

    • Nilo

      Manhattan and Chicago grids work fine. Just interrupt the grid and plop a park down.

      • Nilo

        I think the far more substantive criticism of Alon’s calculation is they underestimate the amount of space devoted to Park. IRC Manhattan is roughly 20% park, 30% street.

    • Joseph

      High density can increase access to green spaces. In Taipei (and to some extent Hong Kong) it means you can live in a dense metropolis of five million, but undeveloped wilderness is a short bus ride away.

      • michaelrjames

        @Joseph: “High density can increase access to green spaces. ”

        That’s the discredited concept of ‘towers in a park’. The real world experience shows the green space on those plans turned into windswept, deadzones, and usually not very green.
        I don’t know Taipei but Hong Kong is both cursed and saved by its hilly topography–it means even living in those dense forests of hi-rise you are only a walk (not bus ride) from dense real forests. A fair bit of Rio is similar.
        But without the imposition of geography, fields of hi-rise are pretty terrible. They don’t compare to the treed avenues and squares of Paris, and as it happens most don’t equal Paris’ overall density either. Manhattan is a case in point. In this context one has to award a lot of kudos to Singapore’s planners because it really is a lush green place by design.

        • Matthew A da Silva

          Singapore learned from Hong Kong’s failures in a big way. Much more focus on quality urban design within an otherwise similar system of state-led, infrastructure-induced high density development. It’s a shame understanding of Singapore’s urban design is underexposed in the West. New World cities could learn a lot about how to improve their contemporary development.

          • michaelrjames

            @Matthew A da Silva

            I agree.
            It does seem to be getting more attention. For example, the role of transit and their aim of creating a 45-minute city. Even The Bro (David Attenborough) has done a program on its green aspects. Due to the large number of expats who have worked for several years in the city-state then return home it is slowly building a kind of reverse diaspora. I’m talking white-collar workers who number in the millions, not the manual workers, and their children. A bit like–no, exactly like–Alon!

        • Joseph

          No Michael, that is not towers in a park. That is a huge, very dense city next to steep mountains. Like Hong Kong except the built-up area is larger, and the mountains keep going for a few hundred kilometers. Traditional Taiwanese urban form is very laissez-faire and works very well if you ask me, though unfortunately motor vehicles are given the run of the place.

          • Joseph

            I should add: my point is that greater density makes it possible to reduce sprawl, leading to greater proximity to nature or at least countryside for more of the population. In some places sprawl is restricted by mountains, but the same principle should hold if you reduce sprawl and increase urban density even when there’s plenty of flat land available.

          • michaelrjames

            @Joseph: “my point is that greater density makes it possible to reduce sprawl, leading to greater proximity to nature or at least countryside for more of the population. ”

            That may be the case on HK island but newtown development is pretty much ‘towers-in-a-park”, like Tung Chung and adjoining Yat Tung. I haven’t seen plans for Kau Yi Chau or Hei Ling Chau but assume it would follow the same model … which I’m not saying is bad given the context. Though building islands like that is not going to provide any ‘proximity to nature’. Whereas Tung Chung is right next to forest/jungle and it has the aerial tramway up to the Buddha at Po Lin monastery.

            And my point is that one doesn’t need ultra-densities to achieve any of that. Not just inner Paris but also the Petite-Couronne which has an additional ≈5m on 657km2. Remember the Haussmannian objective (actually Louis Napoleon’s ideal) was that no one should be more than ten minutes walk from green space. Of course that green may be a lot less interesting than the hills of Hong Kong but that is just a feature of Europe (eco-poor, in diversity terms) compared to Asia (hugely species diverse rich ecosystems).

          • Martin Kolk

            @michaelrjames. Taiwanese and Hong Kong urban planning are totally different. Most of Taipei and most Taiwanese cities are built on a small scale with small lots, where minor private builders build most of the houses, while in HK it is dominated either by the public or by a handful of gigantic construction companies. The result is that urban form in Taiwan is much more organic, where density largely traditionally have responded to market forces and transit availability.

            (this is a bit of a simplification, e.g. older parts of Hong Kong such as Kowloon have urban forms much more similar to Taiwan, and the most recent developments in Taiwan, such as Xinyu, have some of the imprint of the giant master plans of HK)

            If you want to see a more decentralized small scale market-oriented high-rise model in Hong Kong that could be arguably called “tower in a park”, you could look at Mid-levels (that in my mind work pretty well). The kind of identical HK tower-in-a-park suburbs, made from a single master plan, such as Tung Chung is a much later development (and is indeed pretty dreadful urban planning), but is very different from urbanism in Taiwan or Japan.

            Singapore is as described earlier a more thoughtful and better-planned version of the Hong Kong public housing and master plan approach (though HK at least has the older city centers), but I personally think the lack of focus on pedestrian movement and traditional urban form is quite unattractive.

            The older city center of HK, or most of Taipei could not be called, tower-in-a-park, any more than mid-town Manhattan.

          • michaelrjames

            @Martin Kolk:

            If you want to see a more decentralized small scale market-oriented high-rise model in Hong Kong that could be arguably called “tower in a park”, you could look at Mid-levels (that in my mind work pretty well). The kind of identical HK tower-in-a-park suburbs, made from a single master plan, such as Tung Chung is a much later development (and is indeed pretty dreadful urban planning), but is very different from urbanism in Taiwan or Japan.

            I don’t know about Taiwan because I’ve never been there (or technically, never got out of the airport, half a lifetime ago when, assured by travel agents in HK it would be ok, they didn’t let me in!) but I do know a bit about HK and Tokyo. No, most of HK Island, especially mid-levels on the Peak, or Kowloon is anything like tower-in-a-park. Mid-levels is indeed fine, not least because of its proximity to everything, better air than most places in HK, and walking distance to several walking trails along the island. But most of us could not afford to live there. Re Tung Chung, I wonder with those remarks whether you have been there? I might have thought (probably did think) similarly before experiencing it, but it is actually pretty good–indeed probably the best such development in the world I can think of. (Perhaps there are some good ones in Singapore, but nothing like it in Japan or the west afaik.) I spent about a week there, on about the 30th floor of one of those 64-floor towers splayed in a big semi-circular arc you see from the airport express train (passes right in front of them). Everything is all linked up by covered walkways and it is super easy and quick to get around the complex. While it would be easy to have been some hyper-bland mall monster, it is rather good and overcomes its innate mallishness. It has all the ‘town’ facilities you’d want in shops, restaurants, cinemas, bars (including a British pub to cater to many Brit air crew who live there, or spend nights there (several big hotels), in between flight duties at the nearby HKI; there is a frequent bus service, takes about 10min; the Metro/Airport Express doesn’t connect them without travelling halfway into Central and swapping trains–ie. the AE passes thru Tung Chung but not Tung Chung Metro station). It has a pretty good town square (open at ground level with greenery) bordered by restaurants etc. And it has excellent connections, via the 28 minute Metro trip to Central, or of course the world via one of world’s great airports just across the road (an a shopping, entertainment destination in itself). Then you also have Lantau and its trails thru genuine, very big wilderness (≈100km2), including the aerial tram to the big Buddha at Lo Pin monastery on top of a mountain.
            What it doesn’t have is that indefinable grit one comes to love about HK, instead having a very BoBo sameness in the residents and ambience. It wouldn’t be my choice of where to live but I didn’t make fun of my friend’s choice like I thought I might have.

            To crossover to reply to Eric2 but on the same theme, if western developers could build anything like this then ok. Instead they create this:

            Penthouses and poor doors: how Europe’s ‘biggest regeneration project’ fell flat
            Few places have seen such turbocharged luxury development as Nine Elms on the London riverside. So why are prices tumbling, investors melting away and promises turning to dust?
            by Oliver Wainwright, 02 Feb 2021.

            Stretching across a 230-hectare riverside swath from Vauxhall Cross to Battersea Power Station, straddling the boroughs of Lambeth and Wandsworth, the Vauxhall Nine Elms Battersea (VNEB) “opportunity area” has been trumpeted as the biggest regeneration project in Europe. When Boris Johnson, as mayor of London, launched the plans in 2012, he described it as “the greatest transformational story in the world’s greatest city”, the “final piece in the jigsaw” of central London. Once a place of low-slung warehouses and logistics depots, it is now a very visible presence on the London skyline. Competing stacks of luxury flats have sprouted along the river, replacing the elm trees that once stood here with a forest of concrete and cladding, a garish collage of mirrored glass, coloured plastic panels and fake bricks.

            Note to Americans: this development is in the stretch of southbank river from the famous MI6 building to the Battersea Power Station (restored at absurd expense, then to be obliterated by these towers!) and the new American Embassy–right up to its 30-metre bomb-blast perimeter! Trump refused to officiate at its opening (the most expensive US embassy ever) because he thought it was not in a good area, and his NYC property instincts might have been correct. The planned China and Netherlands embassies are no longer going to be neighbours, choosing to locate elsewhere. And Chinese investors say they don’t come to London to buy a development that looks like home, and that they want to be on the correct side of the river where all the action is.

          • Martin Kolk

            michaelrjames: I haven’t actually spent time in Tung Chung, maybe it is a bit more lively than my comparison points and has better nature access, though it looks very much like other housing estates on some plans. I have spent some time in Tsing Yi, which I guess was my reference point that is really dreadful, and in the areas between Sha tin and Tai po, that was also pretty dreadful (most of my time in HK has been on HK island). What makes it so depressing for me is the lack of any really urban feeling and facilities, despite concentrations of people (Tsing Yi would be the 4th biggest city in Sweden!) that in a city like Paris or Taipei would be very lively neighborhoods. The HK MRT stops consist often of a single really dull shopping mall (identical to all other ones), and a collection of some even sadder smaller concentrations of shops under some of the housing estates.

          • michaelrjames

            @Martin Kolk

            You’ve got me there as I haven’t been to Tsing Yi (other than zipping thru on the Airport Express or TC Metro line). But I wonder if it is a fair comparison. The expansion of the island by reclamation and its development has been going on over a very long period that predates the airport (and bridge) development so it is not master-planned in the way Tung Chung was. And it is a very industrial zone so has a much lower economic profile of residents than TC; the hi-rise housing was first built to relocate fishermen. Unlike TC, it has a town centre that predates all the new development.

  10. Onux

    For those who know what it is, Kowloon Walled City represents the dystopic peak of everything wrong with densification. Overcrowded, ugly, unsanitary, little access to light or air, poverty, run by gangs, etc. People already use pictures of soulless Hong Kong high-rises to oppose 5 story buildings next to transit stops in California, let alone 25. Telling them that instead of their biggest nightmare you will do worse, will not help your cause. No matter your aims or how correct you may be on the facts, if you message like this you will lose, every time.

    Even as a thought exercise or an attempt to move the Overton window referencing KWC is not helpful. If you propose a reasonable policy that gets traction, opponents will dig up posts like this to say “What Alon really wants is KWC, we have to stop the slippery slope.” Proposing apartments everywhere to get duplex/triplex zoning, or proposing no height limits downtown to get Chicago-style 10+ FAR by right, is moving the Overton window. Proposing KWC is so outlandish it will get you ignored at best, or at worst cause backlash as people feel the need to “climb the slope” (has anyone ever studied examples of “Overton backlash”?)

    To push acceptance of high rise buildings specifically, I recommend Central Park West In My Backyard (CPWIMBY “sip-wimby”) or Upper East Side In My Backyard (UESIMBY “you-simby”). Both are synonymous with wealth as well as high rises, which means you are selling a positive.

    • Alon Levy

      Yes, Californians say “Hong Kong” as a shorthand for “bad,” because they are racist and think Asia is a bad thing. It comes from the same place that led a Caltrain consultant to say “Asians don’t value life the way we do” when Richard Mlynarik asked about projected turnaround times at Transbay Terminal. And what better time than now, when Westerners already see that another culture lives while they (we, sigh) die of stupidity, to habituate this culture of death to a superior way of organizing cities?

      • Brendan Dawe

        Hong Kong is kinda bad? Not in anyway that isn’t an expression of the poison planning legacy of the British Empire or inferior to California, but you don’t get highest-price-to-income-ratio-in-the-world by being good

        • Alon Levy

          Hong Kong builds 4 annual housing units per 1,000 people. The problem isn’t the density, the problem is MTR land squatting.

          • michaelrjames

            @Alon Levy: “Hong Kong builds 4 annual housing units per 1,000 people. The problem isn’t the density, the problem is MTR land squatting.”

            That is serious nonsense. Indeed I think you are trolling.

            Whether Hong Kong is “bad”, in the context of housing, yes it is. Not because of what it builds but what it doesn’t build: anything affordable by a significant social group. It is a big factor in why it is the rich world’s worst inequality. It’s not just the poor but a big slice of everyone who has been trapped in the property price inflation that has been engineered by the property developers aided and abetted by government (who in turn are too influenced by the unelected business representatives in government). In turn this has been a major factor in increasing political unrest, and the reason why last year’s scheduled local elections were cancelled, as they are the main means of political expression permitted.

          • Alon Levy

            Hong Kong might plausibly be the #1 country in the world in the share of housing construction that is social – it’s around half if I remember correctly, vs. 1/3 in Ile-de-France, Amsterdam, and Vienna. (Singapore has a higher proportion of current social housing but most construction nowadays is market-rate.) It just doesn’t build a lot of housing in absolute numbers by Asian standards.

          • michaelrjames

            @Alon “Hong Kong might plausibly be the #1 country in the world in the share of housing construction that is social – it’s around half if I remember correctly, vs. 1/3 in Ile-de-France, Amsterdam, and Vienna.”

            Do you have a reference for that? It is totally contrary to what I have read repeatedly over the decades. Maybe the unrest has provoked some building (for example the low-SES, rental-only Yat Tung estate just next to–but carefully segregated from–Tung Chung is finally getting its Metro extension).
            Oh, and if it is true, then what are you complaining about?

            Oh, ok, I just realised you are not talking of current building? (it remain ambiguous to me). Your figure represents historical building. As I have explained, tediously over and over, building of social housing was world-beating in HK and Singapore in the post-war period but nose-dived after the ’97 handover. They forgot their own lessons in building a more equitable society in which most people are housed adequately.

            Comparing to mature western cities like in France, Amsterdam, Vienna is kinda pointless; and one third is much higher than I would have thought but I suppose in those prime cities it is about affordability for workers who could afford a house in a provincial city but not in greater Paris.

          • Alon Levy

            Carrie Lam responded to the protests by promising to build more social housing, but Hong Kong’s social housing construction rates predate that.

            This link is live and talks about social housing needs. Of note, it’s from April 2019, so a few months before the protests exploded, and around half a year before Lam promised to increase housing production in lieu of agreeing to any of the five demands. Private housing averages a bit less than 20,000 a year, but in 2019 hit a high of 21,000; it looks like a 50-50 split, even though Lam promises 60-40 public or even 70-30 in lieu of agreeing to any of the five demands.

          • michaelrjames

            @Alon Levy

            That appears anomalous but it just reflects two things. The chronic inadequacy of both private and public house construction. And the slump in private construction with a current higher public housing construction–the full title of that article you linked to said “most in 14 years and ahead of official target”. The previous chief, Leung Chun-ying, had pledged to add 20,000 units a year the the social housing stock but he failed. As I said, that continuous failure (since 1997) has led to the government of Lam making noises to correct it but the progress is meagre. The waiting list for public rental housing units went from 97,300 in 2006 to 284,800 in 2016, and today is still 260,000. The umbrella movement began in 2014. The reason it is so high is not just the very poorly paid lower-SES but plenty of the ‘working poor’ who simply can’t afford the apartments the property developers are building–this, combined with the increasing unstable conditions in HK have adversely affected the private sector.

            Other than the huge backlog in social housing, part of the problem is that the HK government raises a lot of money from auctioning crown land to the highest bidder, and this is partly a factor in driving prices to unaffordable levels. I think this shows one result of having such low taxes yet providing high-quality services such as heavily-subsidised healthcare, education and transit. You’ll complain that the MTRC is part of this problem–because they get land at below-market rates and then profit from its development–however it is just a scheme to help fund the Metro etc.

            The low taxation has a cost which is experienced by more and more citizens (well, more like ‘subjects’ now). HK has more USD billionaires per cap than anywhere else, and almost all of them (all the top ten I think I read) get a lot of their wealth from property. Their property Ponzi scheme has long passed its point of sustainability.

            The solution is to ramp up social housing construction and provide relief on auction prices on crown land in exchange for significant fraction of affordable apartments in the subsequent developments. The claim that the development of Kau Yi Chau (midway Lantau to HK Island) to build up to a quarter million apartments with 70% going to social housing is laughable in both claims. Developing those tiny specks islands is both extremely expensive and fairly weird. Maybe they really should look at developing the northern part of Lamma and extend the South Island metro to it. It has to be cheaper to reclaim land directly off Lantau and leverage the existing transit. Though some HK activists claim there is more than the area of these reclamation projects in the New Territories so again it is probably at the behest of the property developers.
            Oh, and increase taxation on those trillions that the billionaire class control.

          • michaelrjames

            BTW, I don’t give much credence to the Asian Fin Crisis of ’97 theory. It was a pretext for the property speculators of HK to get what they wanted: a highly restricted supply that drove demand thru the roof and prices to the stratosphere, and they could build ever-smaller apartments for ever-higher prices.

            Homes as Small as 60 Square Feet Worsen Hong Kong’s Covid Crisis
            By Shawna Kwan, 30 Jan 2021.

            As the city’s population surged in the 1950s, many Chinese immigrants shared apartments with strangers, but over the decades that followed, subdivided flats became less common as the supply of public housing grew. Then the Asian financial crisis of 1997 sparked a six-year property crash that saw prices drop by two-thirds and the government freeze land supply to support private housing. Inadequate construction in the years after the slump helped to create the world’s most unaffordable property market.
            Demand for public housing has far outstripped supply ever since. The waiting time for a home is currently almost six years, and longer for non-priority cases. Those would-be tenants need to wait somewhere.
            With one in five people living below the poverty line, prosperous, modern Hong Kong is among the world’s most unequal developed economies.
            A government-appointed task force is looking into rent control and other regulations to protect the tenants of such units, local media reported this week. The government is also actively seeking more land plots for public housing, although the imminent supply still falls far short of the demand. An ambitious HK$624 billion ($80 billion) proposal to build artificial islands for property development has been met with public skepticism and will take decades to come to fruition.

      • Onux

        Californian’s say “Hong Kong” as shorthand for “density is bad” because you can find photos (sometimes carefully staged and/or cropped) of seemingly unending drab concrete towers with no sunlight or vegetation anywhere. There are many, many people who like sunlight, open space, backyards, greenery, etc. and having these preferences is not a sign of racism. Is the Hong Kong stereotype perpetuated because it fits a political purpose and most people have never been to Hong Kong? Yes, but this happens everywhere (Hong Kong politicians use Portland riots to perpetuate a stereotype of the US as overrun by anarchy and justify political repression).

        Explaining how dense cities like Hong Kong, Singapore and Tokyo can have better outcomes despite (or because of!) density is one thing, making KWC – a place so awful even people in high-density HK wanted to get rid of it – your rallying cry will simply cause your arguments to fail, or at worst give the actual racists a way to win people over to their side by hiding their racism behind the rather reasonable argument of opposing what is commonly regarded to have been the worst urban environment ever (the fact that the terrible outcomes were due to extrajudiciality not density – no building dept = no running water, no police = gang lawfare – is a nuance that will be lost in public opinion).

        What makes Hong Kong a superior way of organizing cities (or an even better question, was KWC a superior way of organizing a city?) Have you asked all of the residents of those high rise towers if they would prefer to live in a single family home or a euro-style walk up if they could? HK ranks high on the Human Development Index because of its high GDP as a city state (evaluating just Manhattan as an entity would give it an equally high HDI), but there are other countries with equal or higher HDI that do not have high-rise cities (Norway, Iceland). On many business listings HK ranks top, on many “livability” indexes it doesn’t rank at all. The “superior” way to organize a city is a subjective one depending on goals and ideals, but as Michael James noted above virtually nowhere on earth has even neighborhood densities of 100k/km2 let alone 200k. While the shift from rural to urban has been a constant fixture in human history since agriculture, so has the drive to suburbanization. If people wanted 200k/km2 density the Eixample wouldn’t have happened in Barcelona, and Manhattan’s population would not have followed the subways to Queens.

        Again, given that density in KWC was 1.9M(!!!)/km2, it is such an absurd edge case that that building an slogan around it does not make much sense, like the people who point at the 575kph TGV record to claim that trains can be faster than aircraft if we only built thousands of km of laser straight track everywhere.

        Covid has no relevance to this discussion. As you have noted density appears to have no impact on Covid deaths (either way, low density NZ is doing as well as high density Singapore).

        • Nilo

          Californians have lots of terrible preferences. We seem unable to get rid of proposition 13 and have sky high housing costs due to NIMBYism.

          It should be rightly noted that building technology has progressed substantially since the construction of both the Eixample in Barcelona, or the suburbanization of Manhattan into Queens. People per square foot of floor area was much much higher then due to tthat

          • michaelrjames

            @Nilo: “People per square foot of floor area was much much higher then due to tthat”

            I don’t quite understand that last sentence. That is, how construction techniques by itself impacted personal space. I’d say smaller families and wealth are the bigger influences. (Perhaps you are referencing the post-war mass-produced SFH typified by Levittown, but we were talking about MFH.)
            Re building technologies, those buildings of the Eixample and most of Paris (up to pre-WW1) will outlast any subsequent construction that uses reinforced concrete. Almost all the apartment buildings on Ile St Louis are 360 years young. Neither of us will be around to know but I’m betting they will still be around when most post-war hi-rise has crumbled away. Copacabana will be a heap of rotting concrete! Of course it doesn’t work that way. The buildings deteriorate to the point the economics favour a tear-down and new build. Maybe they will rebuild to 8 floors only (eventually there will be fewer people) and you’ll have Paris-sur-le-surf! (I guess that already exists–Biarritz.)

    • michaelrjames


      I assume that KWCIMBY is also political, ie. libertarian–the place was left to itself by the HK authorities until it became too much to bear. But like any such arrangement it devolved into anarchy exploited by criminal elements and was in the end an autocracy run by the triads. So yes, no matter what model it is used for, it is not a good one.

      • Onux

        Yes, other than absurd density (Alon’s denser-than-any-neighborhood-on-earth example is still only one-ninth as dense as KWC was!) the salient feature of KWC was the extrajudicial status and thus total lack of government. This situation was so diametric to what Alon considers the strong point of E. Asian governance (high state capacity and planning to respond to Covid, for instance) that it is even more surprising to see it used as an example, even if just in a slogan.

      • Alon Levy

        No, the KWCIMBY hashtag on Twitter is consistently about maximum density and no more, e.g. KWC had a 14-story height limit because it was near the airport, but nobody who hashtags KWCIMBY believes buildings should in general be capped at 14 floors.

        • michaelrjames

          @Alon Levy: “nobody who hashtags KWCIMBY believes buildings should in general be capped at 14 floors.”

          Me too. I believe residential buildings should be capped at 8 floors:-)
          No, not really but I don’t want to live in anything bigger ever again.
          KWCIMBYs must be funded by the developer industry. Do they wear MAGA caps? Anyway, clearly not urbanists …

          • Alon Levy

            How un-Parisian of you, the city is full of taller buildings, and not just HLMs, though the Haussmannian buildings rarely go over 9.

          • michaelrjames

            @Alon Levy: “How un-Parisian of you, the city is full of taller buildings, and not just HLMs…”

            Huh? In the jurisdiction known as Paris, ie. intramuros, department 75, other than churches or monumental stuff, it would hardly be 1% of all buildings. [Hmm, gotta be at least 100,000 buildings in Paris so 1% is 1,000: no there aren’t that number of tall buildings; maybe 0.1%.] I mean there’s so few I can name many of them, like the approx 30 towers (of 31 floors) in the 13th (I lived briefly off and on, on the 21st floor of one in the Italie complex) and the Front de Seine just downstream of the Eiffel Tower has about 15 residential towers about two-thirds of which are 28 to 32 floors. The reason for this is that, as I think you well know, it is exceptionally difficult to get an exemption to the height laws if your postcode is 75xxx. I can think of a few other high buildings but they aren’t residential like Jussieu or the hideous Centre Morland etc. (which, like the NJNYPA and the WTC Twin Towers, shows that city authorities should never be allowed to overrule their own rules).

            In fact the HLMs in intramuros Paris are all Haussmannian, in stature at least, built long before the kind of thing you are thinking of in the banlieus (sincerely I don’t recall any intramuros; those things in the 13th aren’t HLM, to my knowledge they’re all private). Many of the blocks built on the land liberated by the final demolition of the Thiers Wall, and thus next to the Blvd Peripherique are HLM/HBM, and they’re not bad at all. Some of them must be almost centennials as it began in the 30s. Though I’ve not been in any of them AFAIK but it’s an aim of mine.

        • Onux

          It is an absolutely terrible hashtag to use and works against your goal. Yes, KWC was the densest place on earth (I earlier cited 1.9M/km2, but apparently the figure of 50k included people in an adjacent slum; when KWC was demolished it was found that 33k lived there, or a density of 1.25M/km2) but it is impossible to separate that from the crime and gangs, raw sewage in the streets, apartments with no running water, unlicensed “doctors” performing back alley surgeries, and so on.

          An “austere” unit in your plan would be 22.5m2 for one person, but KWC had at best 11m2 per person (certainly less, I assume 2.6 ha with 14 stories throughout, but there were courtyards and lower buildings). Using KWC as a hashtag messages to Americans they should have 5+ people living in a studio apartment, or 14+ people in the average 2 bedroom house. No one will buy into this.

          You have been cited in the New York Times, an article by the Manhattan Institute mentioned you earlier this week, you are building a reputation as a global expert on transit construction costs and other transportation issues. Continue to state KWC as any sort of ideal, even abstractly, and it will come back to haunt you. If you are on the verge of convincing policy makers of a housing change, those opposed will dig up your use of KWC as a hashtag, show pictures of KWC like this:

          and you will lose everyone in the room. They won’t vote for your plan, they won’t take your advice. No one, anywhere, wants to be told they should live in a place where their child’s classroom during the day becomes a strip club at night. That is what KWC was.

          Do you actually want people to live in overcrowded conditions without basic utilities? No, but it won’t matter because the power of the visual/emotional message will overwhelm facts or rebuttal. The average policy maker, let alone average person, will never read this article for details how windows per person translates into reasonable living space. They will see pictures of KWC and that will be it. There are places with high density but good reputations. Singapore is clean, Tokyo is reasonably priced, Paris is beautiful, movie stars live on Central Park West, etc. Pick one or more of those to use as your standard bearer. Sell people that building and living in denser cities means a higher standard of living and a pleasant, or even glamorous, life – not a life of squalor.

          • michaelrjames


            Its exact density is probably unknowable but you’ve inadvertently added a zero. The site was ≈24Ha, and with 100Ha to the square kilometre, if there were 33,000 residents, that gives density of 137,000/km2.

            I suppose Alon’s point (and the KWCIMBYs) is that this number in low-rise is an appalling slum but in high-rise (like the 64 floors of HK’s Union Square) it can be luxury.

          • Onux


            I agree exact density is unknowable, but multiple sources confirm the site was 2.6ha (range of 2.4-2.7), not 24.


            One of these quotes 3.7m2 per resident along with the 50k pop; at 33k that would be 5.5m2 per person. Even if too low, that is not luxury. Especially since KWC was 14 stories or so, hardly a low rise, and Alon is suggesting 25-30, not 64. Even if built to 64 stories KWC would have only had 25m2 per resident, still not luxury.

            Alon and dense urbanists need a better hashtag and model.

          • michaelrjames

            Yikes, my file has a 10x error in area size which I should have picked up.
            However, looking thru the Wiki and those other links, I remain dubious about the million-plus/km2 density. The claim of 33,000 residents is buried in some book. I am more inclined to believe the official census data of 14,617 in 1981 (only a few years before the decision to demolish it was taken–even if it took another 10+ years). Of course that is ‘only’ half the claim for its final density but that is rather less outrageous and somewhat more credible. Because of these uncertainties, and of course its singularity, I don’t think anyone should use KWC as a an example of ‘achievable’ or ‘sustainable’ densities.

            One’s mind boggles at the heat balance of such a place–and in a tropical climate within a dense city that has a heat-island problem already. Even without all the heat from cooking or other activities, it would be like an ant colony that overheats simply from the heat given off by metabolism (and of course ants aren’t mammals which are far worse from this p.o.v.). OK, like an ant-colony they have made 74 air-shafts to relieve this problem, but still … that’s an awful lot of warm bodies in a small volume. It’s more people than at Trump’s inauguration. Maybe a lot of those people use it as a legal refuge etc but sneak out to the city most of their time?

          • Eric2

            There is a hard ceiling on Alon’s career prospects, and it’s due to his propensity to say things that vary between weird and shockingly immoral. For example his KWC aspirations, or else his recent proposal to forcibly inject people with experimental medical treatments as punishment for doing their job badly. It means that he can be quoted in fringe or wonky settings as a subject matter expert, but never be hired by anyone who has to worry about PR for any position of public significance.

          • michaelrjames


            With comments like that you risk Alon striking you down with their space lasers that we all know they control. Either that or unleash their white cat trained to sit on your face to smother you as you sleep …

          • Eric2

            Maybe with all those walls and no surface area, it was like a cave which stabilizes at a mild temperature? Or maybe not. I really don’t know.

  11. Onux

    30*30 high rises would not be doable by smaller developers. The distribution of developers and contractors by size is not isotopic, it follows a form of Zipf’s law. Building a 25 story building is a 9 figure exercise whether the building is 30*30 or a 80*80 euro block; the set of developers/contractors that can build one will be effectively equal to the other.

    If you want to increase opportunities for smaller firms (or increase density in metros not large enough for major firms), you need the missing middle. Developers/contractors that can fund a small subdivision or frame a 3 story single-family can also handle a block of townhouses or a 4-6 story apartment/condo building, in a variety of types (stick frame, 4 over 1 podium, masonry, cold rolled steel, etc.)

      • Onux

        1. You said that 30*30 high rises could be built in metros that do not have firms which can built 80*80 high rise blocks, but this is not true. Any developer/contractor that can build a 30*30 building 25 stories can also build a 80*80 block 25 stories.

        2. Large firms are not more moral than small ones; if people do not want high density, there is no reason to enforce a large firm oligopoly by only allowing the construction of high rise buildings over entire cities.

      • Henry Miller

        It isntisn’t just efficiency at stake. No bank that wants its loans paid back (that is non zero only if the government is doing something stupid ) will loan a smaller developer the money to do this. You can just get a loan to build your own house, but as the few people i know who have done it can attest the bank will demand you put a larger than normal downpayment down. You can get much better loan terms if you have an experienced developer who with a track record to do the work as then the bank has confidence you will get a complete house worth a specific amount in a reasonable timeframe. That developer has the history to build houses, but will never get the loan to build the 30×30 because his history isn’t enough to give the banks confidence.

        In contracting there are levels needed for different projects and it is hard to move up a level. Often when a contractor does there are lawsuits because the entity paying the price is supposed to vet the biders and the small guy shouldn’t have passed.

  12. Onux

    Advocating for the missing middle is not a compromise. At 200k/km2 the entire population of the earth would fit in about 38,370 km2, about the size of Nordland, which is the 4th largest county of Norway. This is clearly unnecessary.

    Only a reasonable number of places have demand for high-rise housing, the Hong Kong’s, Rio’s and Manhattan’s are vastly outnumbered by other cities, let alone towns. The missing middle is applicable everywhere, indeed it was the norm for urban housing throughout history (even rural living in places where safety required a village behind a wall). It is also capable of providing a high quality urban experience that supports transit. I disagree with Michael James that Paris has higher density than Manhattan, however it certainly has high enough density. Amsterdam, Nordic cities, Swiss cities are the same, few high rises but comparatively high transit use.

    Even suburbs can become viable with the missing middle. Going from 1/2 acre lots with single family homes to 1/8 acre lots with half of them duplexes increases density six times. Very (very) crudely speaking this would give Charlotte a higher population density than DC, Boston or Amsterdam.

    The compromise to avoid is the Pacific NW Compromise (c.f. Seattle, Vancouver): getting some high rises by trading down zoning of SFD neighborhoods to prevent the missing middle. Not only can high rise nodes at transit stops surrounded by SFD have lower density than a more even missing middle, but having made the compromise it may be impossible to upzone the SFD later when the “urban villages” are built out.

    If you want to promote density, don’t denigrate the missing middle. Instead talk about the “Housing Triad” or the “Three Thirds” solution (suburban, missing middle, and high rise, each having their place). “Manhattanization” is a slur, in the US speak of Cambridge, MA. Population density is near San Francisco, it is considered charming not dirty like a “big city”, it is largely missing middle but also has a few dozen residential buildings in the 15+ story range. Due to Harvard and MIT Cambridge is also a touch point familiar to those with power across the country.

    • seangillis78

      Good points. In Canada, a well-regarded example of missing-middle housing is Plateau Mont-Royal in Montreal. Mostly attached triplexes and fourplexes, two to three floors. Some bigger buildings and a handful of high-rises. Somewhere around 15,000/ km square. Supports frequent bus service and a metro line, and probably has the highest modal split for cycling of any ‘hood in North America. Similar to Cambridge, the Plateau is well known outside Montreal, as it is quite an interesting place close to Downtown, that people visit for smoked meat/ bagels/ bistros (only half a joke, since I know folks who have pulled into Montreal for an hour just to hit up Schwartz’s deli).

      • Onux

        Montreal is an excellent case. Vancouver boosters love to point out that it has the highest population density of any Canadian city, but this is because Vancouver city is small, only about 25% of the urban/metro population. Many of the high rise nodes in Vancouver (Metrotown, Surrey) are outside of Vancouver city. Toronto and Montreal have higher urban and metro area densities (although differences are not always huge). Montreal also has much lower housing costs (home prices and rent) than the other two cities due to higher home construction (language may play a role in limiting demand to move to Montreal from outside Quebec, but parts of So. Cal. are de facto Spanish speaking yet rent still crushes). Being able to build small apartment buildings everywhere leads to higher production and lower per unit costs than packing high rises into a few areas.

        • Alon Levy

          Montreal has lower housing costs using the Detroit method of “reduce incomes and people won’t want to move there.”

          And no, no part of SoCal is Hispanophone in the way Montreal is Francophone. You’re missing the social relations involved. In SoCal, Anglos are politically and economically dominant and higher-education Hispanics teach their children English, whereas in Quebec the political majority is Francophone and there is a literal language police.

        • seangillis78

          Montreal, in spite of the central area of density expanding over wide swaths, is a fairly low density metropolitan area. Off-island sprawls outward dramatically and my understanding is there is limited regional growth control, such as one finds in Vancouver or Toronto. The suburbs build a lot of housing and bring new land online.

          Montreal is partly inexpensive due to long-term economic problems, but nothing like what Detroit has seen. Of late it has had very strong economic growth, with major hubs for AI and video game design as stand outs, among other things. Prices have been rising accordingly.

          I can’t speak to Los Angeles, but Montreal is a city where French is clearly the dominant language of media, government, business and daily life. There are whole boroughs where you’d probably go weeks without looking to use any English. The metro area (4 million people) has 3 million native French speakers, 1.5 million who speak ONLY French. That’s 1.5 million French monolinguals, versus under 300k who list as only English speakers. Those are the 2016 numbers from Stats Cans Census profile.

    • michaelrjames

      @Onux: “I disagree with Michael James that Paris has higher density than Manhattan, …”

      For the record, I have said that the difference is barely significant with Paris at about 26,000/km2 and Manhattan at about 29,000/km2; depending on what is counted (getting a fix on land for Manhattan is not easy or clear) this amounts to between 8% and 15%.

  13. Onux

    Only 51% of Montreal City residents speak French as a first language; English is 13% and other languages make up 35% due to immigration. In contrast 45% of LA speaks Spanish at home. There are English-only school districts in Montreal. The recent drive to strictly enforce Bill 101 (“native” English speakers born in Quebec get service in English, not English speakers born in Alberta) is recent, starting in 2019.

    To put Adirondacker’s figures in context, from 1996 to 2016, Metro Montreal grew 23%, Metro Toronto 39% and Metro Vancouver 35%. From 1990 to 2010 Metro Detroit grew 15%, while in the City of Detroit population *decreased* 30%. During the same time the Bay Area, poster child for unaffordability, grew 19%. Montreal may be growing slower than Toronto/Vancouver but it isn’t shedding population like Detroit.

    • seangillis78

      I think what makes Vancouver stand out is the steady progress it has made in various areas: densification, conserving farm land, building rapid transit and good supportive local networks, building bike lanes, creating a new urban form, etc. Montreal’s great urban form is mostly a legacy of the industrial era and streetcar era, same in Toronto. The big Canadian cities built their subways out primarily by the 80s – what have they really accomplished since for transit? Small extensions at best. No real upgrades on-street either. Toronto is now a total gong-show for anything related to transit planning, while Montreal has handed the reins to the Quebec pension fund, outcome TBD. Meanwhile Vancouver has built a comparable system in the Sky-Train, but for a much smaller area.

      Montreal and Toronto may still lead in many urban metrics, but Vancouver is improving quickly, while the other two’s strengths are because of legacy investments.

  14. yuuka

    Alon, my old schools had approximately ~300 students per grade, and so about 1500-2000 students overall.

    A majority of schools I’ve seen here have capped out around 6-7 floors, the only schools I can think of that’s really tall is the Eunoia JC (12 floors, enrolment 1250, and the School of the Arts (12 floors, enrolment 1200 but they’re a specialized institution,

    Of course, it bears pointing out that EJC is co-located with a community institution, and SOTA has more space requirements because of its performing arts facilities. Plus, the MOE likes ensuring every school has access to a football size pitch for PE lessons, so that may complicate planning…

    • yuuka

      Accidentally hit reply before I had more to continue:

      Of course, a compromise for euroblocks is that we simply put more into the single block – a primary and secondary school, a community centre, maybe throw in a few shops while we’re there, but that’s not the Singapore Way. They try to make the densification look not so bad, but what they end up with is towers in the park that are quite bad to get around because the floor plates are equally confusing. (best way I can describe them is like pods off a pea plant, each pod with 2-3 apartments)

      @michaelrjames I think a lot of the medium rise comes from the new towns where height limits tend to be less generous. Headline grabbing high rises tend to be further out from the north and mostly within the Circle Line (Pinnacle in Tanjong Pagar, the crazy stuff going on in Queenstown, some in Toa Payoh)

      But then you look at the east and all the single family homes… It probably says something when the government’s plans for new housing in downtown mainly rely on reclamation and the land freed up by the old port, and they still can’t build fast enough with scary headlines like “10 buyers to a flat” that even state media is picking up:

    • Alon Levy

      Huh, interesting about the football pitch. I was backfilling from Tel Aviv, where with infinitely more space than Singapore, the schools have yards in the 40*40 m area that are only partly used for football. (There’s also a culture of indoor basketball in Israel but it’s the #2 sport to football.)

      • yuuka

        Yeah, the Stuyvesant High approach mentioned by other commenters won’t fly here. But I guess it works for them since the school would get primary use of the field, but there’s a policy where the field (and indoor “sports hall”/gym) has its own external gate so it can be used by the public at nights and during weekends.

        So I guess it probably saves on the need to provide external playing fields and such.

  15. Tonami Playman

    The rectilinear grid which this exercise is based on makes it easy to break up land parcels, creates more usable space and has worked for centuries, but has any city implemented a hexagonal grid even if only in a small district. It looks cool in my head, but don’t know how it would be in practice walking around blocks in a zigzag fashion. I do know for sure that it’s gonna be hell for cars to drive around a hex grid.

    • michaelrjames

      Maybe the Fused Grid approaches your concept?
      It is an attempt to address the same issues. Though as their graphics (below) show it is intended for low-rise suburbia. I’m not aware of anywhere it has been implemented (upon checking, there are small attempts in Calgary and Ontario). It tries to provide road access to all buildings while providing an uninterrupted walking/cycling path for people, and via the fused diagonal grid squares the path leads to the centre; though note it still involves some zig-zag walking because the centre of the green squares is some obstacle if only decorative (fountains) or sportive (tennis courts etc). The main feature is the profusion of cul-de-sacs or similar road endings ie. Radburn-like. However those criticisms were from a driver’s perspective, and also most designed cul-de-sacs prevent thru-pedestrian access (from perceived security issues by residents).
      In fact it shares a lot of features with the superblock/superille concept which attempts to achieve a similar outcome starting from an existing fully developed grid. In Barcelona’s Eixample the blocks are octagons, though not symmetrical in that 4 sides are extremely short, ie. the xamfrans, ie. chamfered corners. Those chamfers were a deliberate feature by Cerda to create more open space at grid junctions which today is being exploited to create more people-friendly and greened-up space by restricting car-entry (on a ‘shared space’ basis to local access only).

    • Eric2

      All the zig zags of tiled hexagons sound horrible for transit speed and comfort, as well as cars and probably pedestrians too. People want to travel in straight lines, more than about anything else.

      But an interesting alternative to the rectilinear grid is the triangular grid. You can’t use this for surface streets, because with 3 streets meeting at 1 point there are way too many traffic movements at each traffic light. But you can use it for metro systems, where pedestrians transferring from one line to another do not interfere with each other. And in fact the metro network in London’s West End, around Oxford Circus, does have something approaching a triangular grid.

  16. Michael Whelan

    People are being pretty disingenuous in these comments, claiming that Alon wants people to live in slums. Their very first paragraph makes it clear that KWCIMBY is meant to be a provocative and attention-grabbing hashtag to call out the tendency among some more conservative urbanists (and even YIMBYs in some places) to pretend that missing middle can solve all our problems in ultra-high-demand places like San Francisco. I have heard some of the more moderate members of the pro-housing coalition claim that Accessory Dwelling Units will be able to solve the housing crisis. If we make claims like that, we are setting ourselves up for failure when we get ADUs legalized. As anybody with a basic understanding of math could tell you, legalizing ADUs is nice but will result in a rounding error of new housing production. So then the NIMBYs will come back and say “Look! New supply has no impact!” What Alon is saying is that to solve the housing crisis in our biggest cities, we need to be okay with some skycraper neighborhoods. That should not be a controversial point among good urbanists.

    As any longtime reader of Pedestrian Observations can attest, Alon has always written with a provocative tone. People may find this discomforting, but the comments on this thread show that it gets attention. Before reading this post, I hadn’t thought deeply about how a focus on just missing middle can damage the credibility of the pro-housing movement. Now, I’ve realized that we will need some big buildings; in mid-sized cities like mine, perhaps not skyscrapers – but bigger than the triplexes and fourplexes that are the focus of much YIMBY activism in America.

    Here is Alon’s first paragraph, which makes the aims of KWCIMBY very clear:

    “KWCIMBY, or Kowloon Walled City in My Backyard, is a refrain used by some YIMBYs to make it clear that we favor high density and not the missing middle self-compromise. This is not about the literal KWC, which was poor and hideously overcrowded – the floor area ratio from photos looks like it averaged around 8 counting open space, so the density meant it had maybe 6.5 square meters of built-up space per capita. Rather, it’s about the concept of going as high as possible, using higher floor area ratios (the Upper East and West Sides of New York have 12 residential FAR on the avenues) and generous first-world urban living arrangements to create high urban density. This post is about how it might look.”

    KWCIMBY got its start as a Twitter meme – hence its inflammatory, proactive nature. It would have been less provocative to say “UESIMY” (Upper East Side In My Backyard), but I doubt such a hashtag would have gotten the attention this one has.

    • Eric2

      Let’s look for a second at actual numbers in Alon’s plan. With his proposed density of 250k/km2, the entire US population would be housed in ~1300km2. That’s less than the area of NYC+Chicago (the cities, not the metro areas). Obviously, upzoning NYC+Chicago to Alon’s desired densities will not get the entire population to move to those cities. You could upzone to these densities, but it would be a waste of effort. The market simply would not build units that nobody would want to live in.

      Let’s look instead at Eixample, Barcelona, density 36k/km2. At that density, the US population could be housed in 8300km2. That’s still a tiny amount of land. The NYC metro area alone is bigger than that. So is the sum of just 8 major municipalities (NYC+Chicago+Austin+Houston+San Antonio+LA+San Diego+Phoenix). You could fit the entire US population in the *core* of a few major metropolitan areas, not even counting the outer suburbs. Of course, once again, not the entire US population would choose to move. So the market would support Eixample densities over an even smaller area.

      Need I remind you that Eixample’s density and urban form are considered beautiful and desirable, while KWC’s are considered horrible and dystopian? All Alon would have to do is scale down their desired building height from 40 stories to 6 stories, keeping the rest of the post the same, and call it Eixample rather than KWC density, and the average reader would see it as an example to aspire to rather than a nightmare to be avoided. Of course, the market wouldn’t build even Eixample densities over a too-large area, as I explained.

      • michaelrjames


        Bravo. I knew someone was listening and learning! I award you a doctorate in the MRJ school of urbanism and Haussmannianism. Well, a masters maybe.


        Need I remind you that Eixample’s density and urban form are considered beautiful and desirable,

        Not quite. It’s not exactly its high(ish) density of 36,000/km2 that is the prime issue but it is a reflection of the Eixample’s design defects: too uniform, too relentless, not green enough and too car-dominated. This has become a thing of concern over the last several decades or longer as Barcelona and Spain became more prosperous with more activity, more private cars and more visitors. Not just the Diagonale which is a giant car sewer down the middle that they can never really ‘solve’ (though we’ll see what Paris does with Champs Élysées’ new pedestrian-friendly plan) but the grid creates the same effect everywhere. It is what the superblock plan is intent on breaking up. Too little green space or at least space that is more pedestrian friendly is a result of loss of all the internal courtyards which the Cerda plan relied upon rather than build in such public space in a way that was much more robust to development. Without looking at a map the smallish square around Sagrada Familia is almost the only respite in the whole 7.5km2. It is less worse than it would be otherwise, due to proximity of better urbanism around it; imagine what it would be like if instead of 7.5km2 it was closer to Paris’ 90km2 or Manhattan’s ≈59km2.

        So, one has to mark the Eixample as “not bad, could do better”. Its density is not really the problem–the problems would still be there if it was at Paris average (≈27k/km2)–but rather it is one of the effects of the plan. Obviously, with more open “green” space, while retaining its Haussmannian height, the Eixample’s density would be a bit lower. So it’s a correlation. With a better plan, the only way to keep its current high(er) density would be Alon’s solution: go higher. And that would be awful. For me that’s a very important distinction. Higher densities (than Paris) always result in such negative externalities. Compare it to adjoining areas, such as my favourite of the much older Gracia which was a separate town when the building of the Eixample in late mid-19th century joined it to Barcelona; it has a lower building profile and is terrific with lots of shady small squares and plazas always filled with activity and restaurants and markets etc. Or the Gotic quarter which is ditto. I’d choose to live in Gracia, or even in Gotic despite its infestation by tourists, rather than Eixample. So, Paris has a kind of Goldilocks Density while anything substantially denser pays some price.

        Michael Whelan wrote:

        the tendency among some more conservative urbanists (and even YIMBYs in some places) to pretend that missing middle can solve all our problems in ultra-high-demand places like San Francisco.

        As any simple bit of maths shows, missing middle would indeed solve SF’s housing shortage and IMO largely its affordability issues too. If a mere 10% of its 122km2 was built at Haussmannian density (or less, instead of Paris’ 27,000/km2, let’s aim for >20,000/km2 allowing bigger apartments, no tiny chambres de bonne) then you’d create housing for 240,000 residents. I’m calling Haussmannian of 6-7-8 floors “missing middle” not <5 floors; I think it better optimises the economics and density as Paris proves. This kind of building–as intended in SB827/SB50–is a lot cheaper and quicker to build than hi-rise, not to mention more appropriate for SF's geology than the likes of the Millennium Tower which is slowly sinking into the soft Bay mud, or more importantly is only providing housing for the very wealthy. Plus, Haussmannian style and height is entirely keeping with SF's style and ambience. Indeed, I reckon it would improve it.

        • Eric2

          To be clear, I don’t care if a city is built in Eixample/Paris style or with glass towers at a similar population density. That should be up to the developer. Glass towers to achieve high density seem to be popular and successful in parts of Vancouver, Toronto, Miami, Chicago etc. and there is no reason they could not work similarly elsewhere. My comment was about average density not urban form.

          • michaelrjames


            I rescind your degree, Go sit in the corner with your dunce cap on! And before you go home today you must write out one hundred times on the black/whiteboard: “I must try harder to be a better urbanist.”

  17. Henry Miller

    You are asking the wrong question. The question isn’t can you build it, the question is if you build it will they come. Yes the downtown two bedroom apartments rent for $2000/month in cities where house costs are not out of control. However if we allowed building unlimited amounts of them (which we should!), how long before supply meets demand and rents drop to more reasonable levels that don’t support building more of them?

    In the suburbs you can find a much larger house (including a back yard) for a lot less money than that apartment – even if you factor in the car payments required to live there. Yet nobody is building a large apartment for middle class family with kids. You get apartments for poor families (who can’t afford something larger/nicer). You get apartments for those with no kids (mostly downtown). Everything else is single family.

    If the reason for this is the market has spoken and these people want a single family house, then we should give up: people won’t move into these ideas and the problems they are trying to solve won’t be (or something completely different is needed?). However if it is because you just haven’t found a way to lure them in, then there is opportunity.

    This opportunity is hard. Kids need to be able to run around “like a herd of elephants” without disturbing the neighbors. Kids need to have the space indoors (when the weather is bad) to run. Kids each need their own bedrooms, plus a spare for guests. The parents need their hobby rooms (man-cave…). The kitchen needs to be large enough to cook meals in (when you have kids restaurants are not affordable for every meal).

    Location matters too. Don’t start in a “food desert” because that will drive away renters who can afford other choices. Don’t build where there are bad local schools – even though good parents make for good schools, bad schools will drive away your renters. There need to be good local parks – no drug users/prostitutes – your renters can afford to buy a house elsewhere. Note that everything in this paragraphs is probably in contradiction to the requirement to build near good transit and downtown!

    We (this doesn’t apply to everyone, only those reading this blog) want people to take public transport most of the time, which means transport need to get to the grocery store, and allow getting groceries home. Since you can’t carry as many groceries on a bus/train as you can in a trunk that means the grocery store needs to be convenient enough to your daily routine that you shop daily.

    Note, I’m talking middle and upper middle class. People who make a good income, but not enough to be rich. They want to use their income to upgrade their lifestyle, but don’t have enough to do everything so they need to compromise. Until you can make these people want to come this is “another liberal plan that ignores reality”. The rich have their mansions, but they can afford weird things, best to ignore them as they are much harder to change.

    My experience with prices is with Minneapolis and Des Moines – SF will have a different price point, but the idea still applies.

    • michaelrjames


      Location matters too. Don’t start in a “food desert” because that will drive away renters who can afford other choices. Don’t build where there are bad local schools – even though good parents make for good schools, bad schools will drive away your renters. There need to be good local parks – no drug users/prostitutes – your renters can afford to buy a house elsewhere. Note that everything in this paragraphs is probably in contradiction to the requirement to build near good transit and downtown!

      I think your whole post, while well intentioned, misses the critical factor: high(er) density is autocatalytic for those desirable things. True, this is less obvious for US cities and it does need a bit of proper planning (schools, transit, zoning for mixed use, sensible streets instead of giant wide car sewers etc). But it is exactly this organic autocatalytic feature of Haussmannian development that makes, and keeps, Paris so fantastic. With boulangeries on every block, local food markets, small (and big) cafes, restaurants, bars, creperies etc simply everywhere. I’m not talking of the fancy tourist districts but the entire 89km2 of intramuros Paris (and most of the Petite Couronne is not so different). Good urbanism drives out the bad as long as the correct policies are in place.
      Of course, by high(er) density I mean in the low-rise format, not the hi-rise towers-in-a-park format which fail to generate good urbanism even in Paris (suburbs). In east Asia their hi-rise can generate fairly good urbanism but not universally.

        • michaelrjames

          @Eric2: “I’m pretty sure Paris is not considered a good place to raise kids.”

          Seriously, you’ve done it again ollie …
          Now, while it’s true that there is constant migration of people moving out of intramuros to the banlieus when they want to start a family, plenty remain and personally, as someone who grew up in the boring suburbs, I think it would be a great environment to grow up in. One friend of mine had three young kids and lived in Paris; quite apart from both he and his wife being medics in the frantic intern part of their careers I don’t know how they did it–except that it would have been easier than trying to do it in the ‘burbs and all the commuting needed. It is such a safe yet stimulating place where the kids can walk everywhere or take the Metro or bus; remember the hysteria in NYC about “the world’s worst mum” who let her 9-year-old travel alone on the subway. Well, Parisian kids do it all the time (something shared with Japan). Intramuros Paris has maybe a hundred schools which includes some of the most prestigious in the world, such as Lycee Henry IV next to the Pantheon (possibly the oldest public highschool in the world since 1794, before that an abbey founded in 506) and with admission on merit, an alumnus of more Nobel winners, overachievers and presidents–including the current one–than you could shake a baguette at. The restaurants are child-welcoming. The city has plenty of Ecole Maternelle and childcare places (but then every place in France has that though as you might imagine Paris is especially pampered), and every park has a fenced-off, dog-free childrens playground. Childcare takes 5% of household income compared to 36% in UK, 32% in USA. But don’t believe me, here is an American mother:

          Trapped by European-style Socialism—And I Love It!
          Maybe working moms can have it all—in France.
          By Claire Lundberg | Nov. 2, 2012

          But since my husband and I moved to France two years ago, this child care question isn’t one that we’ve had to think about. Why? Because of three very progressive child care policies instituted by the French government. In brief, the French government provides: 1) inexpensive municipal day care, 2) tax breaks for families employing in-home child care workers, and 3) universal free preschool beginning at age 3. Together, these make quality child care so affordable—even in expensive Paris—that we’re actually considering extending my husband’s work contract and staying in France until our daughter is school-age just to take advantage of them. While I don’t see the United States turning into France anytime soon (certainly not with Paul Ryan’s budget), these ideas merit serious discussion. Even instituting one of them would revolutionize the lives of middle-class U.S. families.
          Though many of these policies were put in place to combat France’s falling birthrate, they have had the added benefit of getting mothers back into the workforce. After a period of paying women to stay home with their children, the French government realized that many women wanted to return to work but needed child care solutions to make this possible. This is where the government has focused its efforts, and to mostly positive results. Over 80 percent of French women work, as opposed to just under 60 percent in the United States. Though employment declines in both countries for women as they have children, in France it’s still over 80 percent for women with one child and impressively over 50 percent for women with three or more children.
          Women who work full time often enroll their children in government-run day care called a crèche, which will take children beginning at 3 months old. Most crèches are open the length of the workday, from 7:30 a.m. to 7 or 8 p.m.

          We could ask Biden’s newly sworn in Secretary of State, Anthony Blinken who did all his high schooling in Paris at École Jeannine Manuel (wiki: “located in the 7th and 15th arrondissement … home to 2,400 students of 80 different nationalities. … ranked the best high school in France for the seventeenth consecutive year in 2019,[3]”).

        • Alon Levy

          Sure it is, what are you talking about? To the extents parents suburbanize, it’s because children are expensive and urban rent is too. But there’s no sense that only very rich people can raise children in the city in France or that it’s inherently better to raise them in suburbia.

    • Jason

      Your complains are valid, but uniquely American. Let’s take my home town, New Taipei City, Taiwan.
      1. Land is scarce and extremely valuable. If you move far away you at most get small detached homes with no garden.
      2. Kids are disciplined at home and do quieter activities like reading or watch TV or video games, or they play outside at school or in the park.
      3. Kids share bedrooms
      4. No spare rooms unless you have 3-bed+ (not uncommon, but the bedrooms could be quite small). 5-bed+ is for the rich.
      5. Kitchens can be small (relative to US) and functional. You don’t need an island or a super sized fridge.
      6. Food and groceries is everywhere; few neighborhoods without some sort of market (traditional market or supermarket) and at least a Chinese place where you get bento boxes or pick whatever you want out of a selection of 20+ dishes. Hurray density!
      7. City != bad school; in fact city = good school. Plus, at high school level you are not restricted to your district.

      My home town was built when it was a poor developing country. America is so rich I’d expect they could do much better. Architecture could be prettier and higher standard. Suburbs could start to be densified by having dense town centers around train stations like in Japan, with existing commuter lines upgraded to provide better all-day service and lots of mixed use. Cities do not have to be crime-ridden and poor places forever. Some cities already have relatively nice and gentrified parts. Homelessness and poverty can be greatly alleviated if folks would just stop blaming the victim. It puzzles me why schools can have such terrible quality in a country that has such a rich government. What I see in America is a lack of vision and action. What I see is complainers wanting to live in the past and not in the future. What I see is people who don’t even understand the possibilities if we just learn from abroad and embrace change.

      • adirondacker12800

        Suburbs could start to be densified by having dense town centers
        The existing ones usually already have one. They were suburbanizing before automobiles got cheap.

      • Eric2

        “Kids are disciplined at home and do quieter activities like reading or watch TV or video games, or they play outside at school or in the park.”

        There’s already enough of a problem of obesity, we don’t need to make it worse by expecting kids to sit in front of a book or TV all day.

        Small kids in a park need parental supervision, partly in case they get lost or hurt themselves on the climbing toys, but more so because it’s not safe for them to cross the street to get to the park. The great thing about a private back yard (particularly if fenced off) is that they can go and stay there unsupervised with no danger. Admittedly typical US back yards are much bigger than needed for this purpose, but in the UK for example it is typical to see smaller yards, often behind row houses, which are great for this.

        Now it’s worth emphasizing that most people have small kids for maybe a 10 year stretch of their lives. Before and after that there will always be a market for high density city living with the practical and cultural amenities it allows. But some fraction of the population will always be better off with a house and yard. And that’s fine. Let them live their preferred lifestyle, and let us live our preferred lifestyle (Hausmannian blocks or glass high rises, depending on the person) too. That’s called freedom and tolerance.

      • Henry Miller

        Only part of that is American culture.

        1: in America land is not scarce or cheap – except in city centers. If this is any part of your argument for density, then suburbs are better because there is enough land to have them, and you have lost because your arguments don’t apply.

        2: In summer we try to apply that to kids in America: it doesn’t work well. Kids get energetic suddenly and at times when you can’t go outside (stop running and come eat is a regular shout at my house). In winter it is worse: it is expected to get to -10F/-20C this weekend – my kids might go outside, but not for long, so they need an indoor outlet for energy.

        3: That applies to the poor in the US. My post is about the middle class who would like to spend the money on better. If this is your argument everyone will go back to the suburbs. See also 1: land is not expensive, so there is less pressure.

        4: people are divided on this. Some don’t want/need the spare room, some do. 5+ bedroom is rare, but becoming more common as people want better.

        4-b: second/third generation immigrants from crowded countries starting to look for 10+ bedrooms because they can afford it and their culture is multiple generations living in one house – they have seen other Americans with one bedroom per kid, and want that, while also having the entire extended family under one roof. Not an issue for the majority, but something to think about.

        5: kitchens can be small. (an if shopping is a daily thing you don’t need as much storage). In American apartments kitchens tend to be small, but there is a reason large kitchens have been in style for decades now. Haven’t had both small and large kitchens I want the extra work space. I have visited one person in Sabadell, (suburb of Barcelona), and the kitchen in their apartment was the type of large kitchen Americans are looking for in a house, so this isn’t just a American thing (I didn’t look, but I believe it also served as laundry). I’ve never seen an Apartment in America with a kitchen this large.

        6: one of my important points. Location matters.

        7: Sadly, in America city means bad school. It doesn’t have to be that way, but it is. I’m not sure how to attack it, but until you solve it the middle class won’t move in and that limits you. Too many of the poor don’t care about school (other than as a day care), and so won’t give their kids the support they need to do well. (city schools are not rich, but parents have more to do with the problems than money)

        > Architecture could be prettier

        I find it odd that the type of people who move into denser housing in the US are the type that like grey buildings that all look the same. I have noticed that condos – a fancy name for a duplex – have started to look a bit nicer, maybe this will change too.

        > and higher standard

        Codes in the US are actually pretty good. Most people confuse what makes a good building with what looks strong but is really weak. Many of the things you call higher standard may in fact be weaker and less energy efficient. I don’t know your background, but I know just enough about building to know that most people who make that claim have no idea what makes a good standard. As an example, what qualifies is a passive house in Germany (no heating or cooling needed) is so inefficient that it just barely even meet codes in the US and will need HVAC to be livable.

        > why schools can have such terrible quality

        Schools in the US are actually pretty good overall. We are a large country, and there is a lot of variance as a result. My thesis is you will never get much density improvements if you don’t go after the type of person who looks at school ratings when choosing where to live, which means we can throw out all the bad schools from our consideration. The best schools in the US are as good as anywhere else, so but there are bad schools bring us down.

        I live in America, and I want to make my area better. My main goal is road safety: I’ve lost a good friend to a car. I don’t care if you solve the safety issues by self driving cars except they are not ready yet. Grade separated public transit was ready years ago. I don’t need density except that it makes grade separation more cost effective. You probably have different concerns.

        If you want to make Taiwan better (reasonable for someone who lives there), then you need to start with the reality in Taiwan, you can find some useful things in America to copy, but there will be other things that don’t apply.

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