Building Depth and Window Space

How much window space does an apartment need, relative to its area, and how does this affect building style? A fascinating post from about a year ago on Urban Kchoze makes the argument that modern North American buildings are too deep – Simon calls them obese. Simon contrasts the typical building style in major cities in Europe and Asia with modern North American imitators and argues that the North American versions have too much ratio of floor area to exterior window width, which only works with loft-style apartments, which are not fit for families.

Is Simon correct? Not really. There’s an important feature of the block style in Europe that he’s missing. And this leads to an interesting observation by itself about area-to-window-width ratios.

The issue of building depth

Simon shows a bunch of satellite photos of buildings in a style called the euroblock. Here’s one example from Stockholm, in Södermalm:

The block has a width that looks like 14.6 meters. Midblock buildings have front windows overlooking the street and back windows overlooking a central courtyard; corner buildings overlook two streets. Either way, the area-to-frontage ratio is 7.3 meters. In general, buildings in Central Stockholm, urban Berlin, and Paris in average a depth of 13-14 meters, so the above typology would generate a ratio of 6.5-7 meters.

Simon contrasts this with American buildings. The euroblock typology is very uncommon in the US – New York’s typology is much less neat and liberally uses windows that overlook very narrow spaces. But it does exist, generally in higher-end recent developments. For example, here’s the Avalon East Norwalk, a condo project wedged between I-95 and the Northeast Corridor.

It has essentially the same built form as the euroblock. Its development history is of course different: there are no streets on the exterior, only parking lots, and it is a single project surrounding a big plaza with a swimming pool rather than many small buildings that together enclose a courtyard that comprises several separate gardens. But in terms of how the building looks from space, it’s similar. The width is 20 meters, for an area-to-frontage ratio of 10 meters, well above 6.5-7 meters.

However…

Euroblocks are complicated

The above Stockholm pic is a pretty simple building, conceptually: a linear building outlining the edge of a rectangle. This is not the typical euroblock; I had to look around Central Stockholm to find a fitting example. I could equally well use Hamburg or another such city of the same size class.

But in Paris, this form is almost unheard of, and in Berlin it is uncommon, I think mostly denoting postwar reconstruction. Paris and Berlin are larger cities, especially historically – in the Belle Epoque/Wilhelmine era, when this typology flourished, they were two of the largest few cities in the world, Berlin stagnating after World War Two and Paris growing exclusively in the suburbs. So they’d build up more of each lot and leave less unbuilt space between buildings. Instead, here is what a traditional Berlin block looks like, in this case in Neukölln:

These buildings enclose a central courtyard, as in Stockholm, but there the similarity ends. The courtyard is small, and there are several to a block. All these wings have internal corners with limited window space. Moreover, the wings that do not make it all the way to enclosing the courtyard, like the ones on the buildings north of Laubestrasse, have blank walls facing northeast, because they were built expecting the wing of another building to directly abut them. The wing of the building at the Laubestrasse/Elbestrasse eastern corner likewise has blank northeast-facing walls, and from space looks awkward, like a half-building. All of this was designed for more buildings, but some were never built or were knocked down.

If the euroblock has one big courtyard for the entire block as in the Stockholm and Norwalk examples, then the area-to-frontage ratio equals exactly half the building depth. But as soon as there are multiple courtyards, the ratio grows. The dimensions of the C-shaped building on Sonnenallee (one block south of Laubestrasse) just west of the corner building with which it shares the courtyard are 18 meters of street frontage by 38 of lot depth minus a half-courtyard of 11.5*12. This works out to 546 m^2/71 m, for a total ratio of 7.7 m, even though technically the building is never deeper than 13 m.

The blocks can get even more fractured. Here’s Prenzlauer Berg, in an area wedged between the former Wall and the Ringbahn:

The dimensions of the buildings fronting Korsörer Strasse on the north are pretty consistent. They all have an overall lot depth of about 32 meters, consisting of 14 meters of building, 11 meters of courtyard, and 7 meters of half-building with blank north-facing walls. The side wings are pretty consistently 7 meters deep each as half-buildings. Taking the pair of buildings flanking the second courtyard from the east as an example, they together are 35*32 minus 21*11, for 889 m^2/99 m = 9 m.

In Paris, building forms vary. But here is an example with wings, in the 17th:

The courtyards are smaller than in Berlin. Taking the second building from the west, we get 35*25 – 11*13, or 732 m^2/98 m = 7.5 m. When the courtyard is only about as wide as the building is deep, the above typology, similar to the image from Neukölln, generates a ratio equal to 5/8 the building depth, and not 1/2 as in the Stockholm example. The Prenzlauer Berg typology generates an even higher ratio, a full 2/3 of building depth if the courtyard is a square of side equal to the building depth.

And this matters. Buildings with simpler sides do get deeper in Paris. For example, this building in the 16th, wedged between two streets:

The depth of these buildings is 18 meters, so the area-to-frontage ratio is 9 m.

What does this mean?

My choice of the 16th and 17th in Paris for my examples is not random. Western Paris has been rich from the moment it urbanized – families of means choose to live this way. In general, within the family of euroblocks, the more desirable areas seem to have buildings with a slightly larger depth – the more working-class parts, such as Eastern Paris, have shallower buildings. Rich people would all else being equal prefer more window frontage space, but all else is not equal, and they prefer bigger apartments.

There is a definite limit on how deep buildings can be and how large the ratio of area to window frontage can be, but it is not as low as Simon posits. Ratios in the 8-9 region are not unheard of in old European buildings, and it stands to reason that euroblocks built in an environment of more prosperity, such as that of the early 21st century, could go slightly higher.

Moreover, the Norwalk example of a deeper building without wings is generally preferable to the traditional Berlin and Paris form of shallower buildings with wings. In Berlin, the apartments with street-facing windows are the most desirable. Historically, the wings were for the working class, which had to make do with narrow courtyards – sometimes narrower than today, the original statutory limit being less than 6 m wide due to 19th-century fire regulations. So the evolution of the euroblock is likely to be toward its American condo form.

62 comments

  1. michaelrjames

    Nice post. This is an interesting topic but I am surprised you haven’t discussed modern buildings at all, well except Avalon East Norwalk which appears to be quite low (maybe 3 floors?) and suburban (you’re comparing apples and oranges here). The problem with modern buildings is that they have simply filled in those courtyards so that traversant apartments barely exist anymore. Ventilation has become almost totally mechanised and lighting artificial. The property industry has even invented some nu-speak for this, with single bed apartments with no external windows and “borrowed light”.

    At first I thought your subject was going to be about windows per se which triggered my dislike of the other modern design habit of wall-to-ceiling and wall-to-wall glass. People think I’m a bit crazy when I talk about this because they have been so brainwashed by the industry and the glass thing has been fully normalised. I have a growing collection of photographs of new high-rise apartment buildings which have 100% glass curtain walls, and the ‘curtain’ is funny because what my photographs reveal is that >90%, sometimes 100% of apartments have their curtains drawn most of the day and night. In Australia this doesn’t stop them heating up like an oven especially as they don’t have any means of allowing airflow–no traversent apartments except perhaps those on corners–and no windows (like clerestory) that can be left partly open without risking security and weather incursions. Some leave their aircon running 24/7 which is nuts.

    These modern practices are not improvements due to modern tech or whatever, but merely optimisations by the builder and property agents for their benefit. Obviously it frees up a lot more space for conversion to saleable area, and those glass wall panels are the easiest and quickest means of erecting the external wall. It is the future owners who ultimately pay the cost of all this poor design, in discomfort and dependence on electric devices to make the place bearable.

    You are right about those 17th arrondissement apartments you show. Clearly they are grand apartments with significant internal courtyards and you can also see a lot of courettes which essentially are airshafts for smelly functions (bathrooms, laundries, kitchens etc). Interesting that they are on Boulevard Péreire (which is built over the Petite Ceinture railway) as the Péreire brothers were the top financiers and property developers of their day (overtaking James Rothschild from whom Emile Péreire had learned the game). Quite feasibly that building itself may have been one of their projects.

    You are right about most apartments elsewhere in Paris have smaller courtyards, Clearly it is the pressure created by density of living and the cost-benefit calculation that means only the very prosperous have those large courtyards. But you won’t be surprised that I would rather that Parisian design (smaller courtyards + courettes; plus more sensible windows and high ceilings) than the modern compromises. I won’t live in a modern (post-war) apartment. But also note that in Barcelona’s 19th century expansion, ie. Cerda’s Eixample, possibly trying to improve upon Paris up to that time (the 17e building you show is late 19th or early 20th, ie. post-Haussmann) they provided quite big courtyards. However, they were too big and inevitably as population pressures mounted those courtyards were filled in, often with illegal modifications but once built, rarely reverted. Sometimes the courtyards effectively disappeared, so it is always better to design something that is functional and will last the test of time.

    • Alon Levy

      Ooh, yes.

      1. Traversant apartments can be nice, but there are caveats. In Paris I had one but the backside was not well-windowed – it was a half-building. I could open the window and it could create breeze, which was nice, but it wasn’t amazing for lighting. In Berlin my previous apartment was fully traversant, but the floor plan was similar to the apartment in the CityLab link SCC posted above, which has obstructed passageways and therefore no airflow. I lived on the top floor, which meant the apartment overheated in the summer. In general, wing buildings in Berlin were not traversant, hence all these half-buildings in the satellite photos.

      2. The trend of bigger windows is good – it means more lighting. No idea why Australians think passive solar design is bad, but my current place, built in 2015, has a lot of window space, and is fine. I also have a corner, which is enough for summer airflow.

      3. The Norwalk building has 4 floors. It’s tall enough for a fifth – a mixed-income urban apartment building would have small apartments with dormers. But this is high-income housing. It’s pretty suburban, yes, but taller examples of the same species exist – I focus on this one purely because I stared at it a lot while drawing high-speed rail maps; if the building weren’t there, the land should have been used for HSR realignment, so I spent a lot of time figuring out how to go around it.

      4. Roger Senserrich of Politikon brought up the Eixample on Twitter! It’s block-wide courtyards, with very deep buildings, in the 20-30 meter range. A few have small airshafts in the middle, much like New York Old Law Tenements, which are mostly in that depth range too, but many do not even have that.

      5. In Berlin the history of the wings and courtyard fillings is the opposite: they were built from the start, but many have been knocked down because they were the least desirable buildings, and were built to lower standards. (The CityLab article mentions that, as does Wikipedia.)

      6. This is Europe, what mechanical ventilation? My guess is that my income is in the 97th percentile of the German income distribution and I don’t have one, nor a drier. Then again, I remember reading various moral panics about AC back when Singapore had a corona flare in the migrant worker dorms and looked worse than Europe, where now its infection rate per capita is something like 2 orders of magnitude less than Europe’s corona-safest country, Finland.

      • michaelrjames

        1. Of course one would always choose a traversant apartment but they are more expensive (for this reason and also by definition mostly big apartments). Naturally, over time a lot have been converted into smaller apartments. I am not totally sure but I believe almost all the buildings on Ile St Louis date from pre-1660 (when the project was more or less complete) and, except for the few grand hotels (Lauzun, Lambert etc) most apartments would have been traversant–because the whole island was built as an upmarket enclave. Certainly the courtyards are small and I believe original. However, most big apartments would have been divided up and certainly the one I lived in I don’t believe there was a single traversant one remaining; mostly you were on the courtyard or on the street, not both. I can’t complain because I wouldn’t have lived there at all without affordable studios. Like you I too lived without a dryer or aircon etc. (however I quickly got fed up with laundrettes the closest of which were over a bridge, so I bought a special Miele washing machine–especially narrow for such tiny apartments; come to think of it, it was a combo but the drier was broken–I bought it secondhand). It did suffer from some hot summer nights, and I’ve heard Paris has got noticeably hotter over the decades. That’s when you really fantasised about a traversant apartment!
        I may be a hypocrite re AC. I hate sleeping with it on but would still want to have it, if only to pre-cool the bedroom down (which as it happens last night I did for the first time this summer–it was 30-34°, east coast Australia is back in heatwave zone). (Yikes, Sydney is forecast 36°C tomorrow.)

        2. Bigger windows are one thing. I’m talking about the entire exterior walls being 100% glass. Terrible. Combined with another absurd trend–removal of eaves or any shading, and it is even worse. As to “No idea why Australians think passive solar design is bad”, it is more that the property developers own the politicians and get the building code they want, not what people want or even what architects or designers recommend. Oh, and Australians are quite new to apartment living–approx. the last 15 years–and are mostly young (though increasingly popular with downsizing retiring boomers) and seemingly accepting of what they’re presented with.

        4. The Eixample. It was all built as perimeter block with large courtyards. They were filled in pretty quickly apparently. The lesson is that they should have designed/built smaller ones that were not possible to remove or adapt to other off-design purposes. That’s why I don’t complain about the small courtyards of most Parisian blocks. Or tight regulation & enforcement by authorities (things not always present in Club Med). Here’s Peter Rowe (Building Barcelona: a second renaixenca):

        Covering nine square kilometers in area with 550 blocks around Barcelona, largely towards the hills and to the north-east, Cerdà’s scheme made little to no reference to the old city. Instead, a rigorous rule structure was presented, based both on his prior and on-going empirical investigations of the existing city’s drawbacks and upon other layouts of streets and blocks from elsewhere in the world. From these analyses a 113.3 square meter block was considered to be ideal, separated by 20 meter wide streets , for a nine square grid patter–roughly a neighbourhood–at 400 meters on a side, or easy walking distance. The corners of the square blocks were to be chamfered–the xamfrans–providing for better traffic circulation, more potentially active public space, as well as more light and air at street level. Further, a height limit of 18 meters was imposed to be changed later in 1891 to 21 meters, and allowable built area, within each block, was limited to 7,100 square meters of floor space, thus permitting passages and movement through the center of each block and ample open space for landscaping at the core of each block.
        …. The 1890s, or thereabout, also saw the arrival of a genuinely Barcelonian version of the apartment building constructed in the Eixample. Often rising seven stories in height, a ground floor with expansive floor-to-ceiling heights facilitated accommodation of commercial enterprises, with the piano nobile above supporting the opulent interior lifestyle of the well to do, followed, in section , by the remainder of the principal dwelling, apartments for rent and, finally at the top, by domestic quarters. However, the Eixample of the 1890s and certainly of today, except in broad outline, is not what Cerdà originally envisaged. For instance, the ratio between built and open space within the blocks was obliterated by pressures for further real-estate development.

        6. Hah, yes, that reminds me of my tiny lle St Louis studio with an internal bathroom. I fitted a time-overrun extractor fan (the 100mm duct went thru the kitchen and used its window). Linked to the lights it stayed on with the lights and then you could set the time it remained on after the light was turned off.

      • michaelrjames

        I’ve read the Urban Kchoze article several times and while I may have this wrong (or it is exactly what he and his ratio are saying) but the difference he highlights between the US and others, which he labels as “obese”, is what I was talking about above in my first posts. And related by your observation of “This is Europe, what mechanical ventilation?”. In Europe via courtyards which may be quite small, or even courettes (air-shafts), most rooms have direct egress to the outside while in the US (and Australia) they have allowed themselves to revert to a previous age on the pretext than mechanical devices can solve the problem, ie. increasingly removed building code (or allowed it to be subverted) that, for example, finally acted to remove the terrible crowded tenements of NYC (long, narrow internal windowless rooms housing entire families etc).

        I was confused for a while because his term ‘obese’ really refers to the building (depth) and not the apartments. Thus he gives multiple examples of US buildings with >20m depth: Griffintown, Montreal of 21m; Chicago, 19m; Seattle, 20m; Dallas, 19m; LA, 22m. Though he doesn’t directly say it, my interpretation of all these examples, deduced from his aerial photographs, is that those depths span more than one apartment. The LA case is almost certainly true.

        That is, there are no traversant apartments (other than accidental ones at corners etc). I reckon most of them have long internal corridors down their long sides separating those street-side from the courtyard-side apartments. The clincher is his last photograph, of a recent Madrid apartment block, with his caption: “This extremely deep apartment building in Madrid, Spain, has inner courtyards that reduce the effective depth of the building from 25 meters to just 12 meters”.

        Incidentally, as I explained in the earlier post, in areas outside the wealthier (and outer) zones (as in Alon’s examples in the 16th & 17th arrondissements) Paris has actually converged on the US model (except for the mechanical thing): originally traversant apartments have been divided up into at least two apartments, one on the street and one on the courtyard. In essence, via market forces in both situations the arrangements have converged to extract value from that external wall. The only thing that can overcome it is regulation. The Europeans do it by the use (mandated?) of courtyards while the Asians go for those H-shaped (or snowflake) apartments (for hi-rise because courtyards don’t really work except when they are directly on the outside). In the Anglosphere we’ve reverted building code in acceding to the property developer lobby and to shoving endless ducts into internal ‘chimneys’ …. because they can, and it’s ‘modern’ technology.

      • SCC

        Just to let you and Michael know, the English-language translation for the French term “appartement traversant” is “floor-through apartment”. In the Anglophone architecture community, floor-throughs are associated with cross-ventilation and Le Corbusier’s design of the Unité d’Habitation building in Marseille, while in the New York real estate community, floor-throughs are associated with brownstone conversions from single-family to multiple-unit homes.

        • michaelrjames

          @SCC

          No, I haven’t ever heard of “floor-through apartment” used in the Anglo world but then possibly there are very few apartments like that. Corbu’s through-floors was clever design and a bit surprising it never took off. It saves in that only every second (or third) floor has a communal corridor. OTOH the penalty for that is that all traversant apartments must have stairs to a foyer on a floor above or below. Because of that it may not save as much space as imagined? Also not great for access (including disabled access) … But good for creating many more traversant apartments, all other things being equal.

          • fjod

            Flats/apartments with facades on different sides are usually called ‘dual-aspect’ in the UK and Ireland – although as far as I understand, ‘traversant’ seems like a subset of dual-aspect. ‘Floor-through’ is not used.

            Such properties are not uncommon; one flat per floor (=traversant) is the most common way of subdividing old buildings (or of old buildings that were always intended to be subdivided), while the ‘scissor flat‘ is a particularly British design of this type.

      • adirondacker12800

        3. The Norwalk building ….. I stared at it a lot while drawing high-speed rail maps; if the building weren’t there, the land should have been used for HSR realignment, so I spent a lot of time figuring out how to go around it.

        If the very high speed trains don’t go through Norwalk you don’t have to worry about it. Amtrak has some cockamamie plan where the very high speed trains avoid going where there are people. If Connecticut is able to pull off their 30-30-30 plan that puts Stamford half an hour from New Haven or Penn Station. 2:15 Stamford to Washington D.C. is good enough. So is 90 minutes to Boston instead of 75.

        100 units at half a million a piece is 50 million. Do that all up and down the line it’s not all that much cheaper than sinking the LIRR into a trench and using that ROW. Don’t do it and it’s too slow. It gets rid of all the obsolete bridges and the noise from the LIRR. And Suffolk County can have every 15 minutes super express to Jamaica interweaved between the New England trains

        • Alon Levy

          The Amtrak, NEC Future, and North Atlantic Rail (né PennDesign) plans are all designed to avoid pissing off Fairfield County NIMBYs, especially ones in sundown town Darien, a community so exclusive that people in Westport call it racist (“Darien rhymes with Aryan,” they say there).

          100 units at Darien prices is like $100 million, but it’s not 100 units in every municipality. Darien is pretty unique in completely lacking any straight right-of-way. In Norwalk and Westport combined I don’t think you need to take 20 houses, and of course hitting a giant apartment building is actually expensive. After Darien I think the #2 municipality in the number of required takings is Greenwich, because there are some townhouses where Metro-North and Amtrak should be realigning the Cos Cob Bridge. I don’t think you need 200 houses between New Rochelle and New Haven, and east of New Haven the takings get even sparser and non-residential, like this 3-star hotel at a Turnpike intersection that my guess will sell for $5 million.

          • adirondacker12800

            And that gets you from New York to New Haven in half an hour?

          • adirondacker12800

            An hour is too slow. Which is why Amtrak comes up with tunneling under all of the Bronx and half of Westchester. Farmingdale is closer to Penn Station than White Plains Airport and could be done cut and cover.

          • Alon Levy

            Amtrak comes up with this tunneling because I can’t personally yell at their managers for proposing a $150 billion program whereas Joe Lieberman’s neighbors can for proposing to spend $150 million on acquiring Gold Coast property.

          • adirondacker12800

            It would be much more than 150 million. And a few decades of delays while they tie things up in lawsuits.

          • Alon Levy

            The Peninsula NIMBYs lost their lawsuits. These lawsuits don’t win, they just try to throw egg on people’s faces.

          • michaelrjames

            Maybe it’s a pity Trump hadn’t played with some expensive toy train sets when he was a young Richie Rich. Perhaps he could have been a train obsessive and forced some overdue reform.
            Or, he could have taken a lesson from his BFF Mohammed bin Salman and locked his UHNW Darien crowd in the Ritz-Carlton in Riyadh (finally a good use for a gaudi Trump hotel! probably one close by in Connecticut? they can even play golf while they get a shake-down) and give them an opportunity to rethink their NIMBYism ….
            (before anyone points it out, yes, these are the exact crowd who Trump gave $2 trillion tax cuts ….)

            Sigh, the US can’t even build a rail line.

          • SB

            @ michaelrjames
            60% of Darien voted Biden.
            For additional context here is the Democrat candidate percentage in Darien
            2012: 34.42%
            2016: 52.75%
            2020: 60.50%

          • michaelrjames

            @SB: “60% of Darien voted Biden.”

            That looks like a bad omen to me.
            Champagne Socialists then?
            Does Janet Yellen live there by any chance? Oops, forgot Alon’s “Darien rhymes with Aryan” , and besides, with that accent ….

          • Alon Levy

            Darien was a Republican town from its modern founding in the 1910s as a WASP flight suburb from Jew-Yorkers until Trump. Before 2016, the bluest it ever voted was in 1964, when Goldwater was so extreme the Republicans only won it by 9%. Today, it remains incredibly white and incredibly exclusive. But that’s not even why I think it’s good to demolish about 100 houses there to build high-speed rail – the reason I think that is that the value of faster trains exceeds the cost of property takings, and at the speed trains would be able to go through, which is around 250 km/h, the noise impact on the remaining houses would not be large. I bring up its wealth just to point out that it is in no way a community with environmental justice concerns.

          • michaelrjames

            Even worse signifier of voters’ expectations of the Biden they voted for.
            Many Americans and others around the world may be too relieved to be rid of Trump and back to BAU to worry about the future, but so far it looks like a real opportunity for real change has been missed. The rich burghers of Darien can rest easy in their multimillion dollar McMansions (or perhaps faux-New England country houses).
            Meantime, while protestors for press freedom are arrested in Paris, in London–weeks away from hard-Brexit–it is protestors against lockdown, and probably next it will be anti-vaxxers.

          • adirondacker12800

            The Peninsula NIMBYs lost their lawsuits. These lawsuits don’t win, they just try to throw egg on people’s faces.
            How that opening date of …. oh there is no opening date. I’m sure they are plotting to sue because the analysis is too old. Page 47 of the NIMBY/BANANA manual.

          • michaelrjames

            These residents of Camden (London) don’t have the money, power and influence of yer average Darienne …

            https://www.theguardian.com/uk-news/2020/nov/28/hs2-urged-to-rehouse-london-council-block-residents-over-disruption
            HS2 urged to rehouse London council block residents over disruption
            Construction making conditions in Camden flats ‘unbearable’, says Keir Starmer, the Labour leader
            Mattha Busby
            Sat 28 Nov 2020

            HS2 Ltd has been urged to fund the rehousing of 175 council households in London enduring “unbearable” conditions due to construction works on their doorstep.
            Just 13% of the 798 Camden-owned homes eligible for mitigation measures agreed in parliament have had secondary noise insulating, glazing and mechanical ventilation installed by HS2 Ltd, they said. However, according to HS2 Ltd, 25% of properties have had the full noise insulation package.

            One problem is that there haven’t been many council houses built for the last 4 decades so long queues to get in and none for these people, except perhaps north of Watford …

  2. Henry

    The linked post I believe has the causation the wrong way around.

    American developers build apartments with few large family units because those are comparatively less profitable, there’s so much pent up demand that a developer could conceivably build a building with even only studios, and one can get away with developing such building forms with thick buildings with few windows. Modern American regulations generally require four walls and a window for a legal bedroom, so the rest of the post about how hard this will be to retrofit is pretty much on the nose.

    Where I live in Seattle is probably one of the friendliest places in the US when it comes to new mixed-use and multifamily housing, with 20+ story towers rising like weeds in several neighborhoods. Of all the new construction available I can’t recall ever seeing a 3-bedroom apartment. 2-bedrooms exist in small numbers, 1-bedrooms are very common, and with studios and “urban 1-bedrooms” together make up the majority of new housing. (An “urban 1-bedroom” skirts the bedroom window regulation by having the “bedroom” walls with a ~1ft gap between ceiling and wall, and is probably legally a studio.) 2-bedrooms and 1-bedrooms, particularly with “urban” style bedrooms, aren’t really suitable for families, but families most likely have more pressing concerns, namely the lack of decent or any public schools in hot urban neighborhoods; Downtown Seattle still does not have a elementary or middle school.

    That being said, if regulations demanded some mandatory family units in apartments (I believe this is more common in Canada) in building, or somehow apartment demand was so filled out developers actually started considering these less profitable niches, the cutout-style would probably be more common than European wings between buildings forming courtyards.

    • Gok (@Gok)

      > Where I live in Seattle … Of all the new construction available I can’t recall ever seeing a 3-bedroom apartment

      Hmm here in Chicago when we had no trouble finding several choices for a 3 bedroom apartment in new construction high rises 2 years ago.

      • michaelrjames

        @Gok

        I think you have to eliminate the top end. I believe Henry was talking about the majority of stock affordable by 90% of the market. In this I think he was largely correct. It has happened in Australia too and has been the subject of much anguished discussion by demographers and housing market analysts. Here it is also affected by our absurd (and absurdly tax-payer subsidised) so-called investor driven buyers: returns are highest on the smallest apartments. It is driving the housing stock into places most, other than property speculators, would rather it didn’t go.

      • Lee Ratner

        I think Chicago is kind of an exception to general American housing markets. In one of the few places without a real big NIMBY problem and with housing prices not that bad for a desirable place to live.

        • Gok (@Gok)

          Well the NIMBY problems are single family zoning in too many neighborhoods and alderpeople demanding bribes for construction approval, but there does seem to be a reasonably healthy pipeline of high+mid rise constructions and even some TOD though the city isn’t growing (and may be shrinking)

          • Henry

            Chicago is more than just maybe shrinking. 2019 ACS estimates put the population of Chicago proper at a 7% decline. Seattle proper has seen a 33% increase over the same time period.

            There’s a less dramatic difference when looking at the metro area (Chicago is up 5.5% from 2000, Seattle is up 30%) but I think Chicago is not hot enough of a market for Seattle to draw lessons from. Seattle has been at the top or near the top of construction activity lists for a while, just very few cities grow that fast in a developed country.

      • Henry

        This is in the context of a city proper and metro area that have both grown by a third since the turn of the century.
        Yes, there is a lot of single-family nonsense. Yes, there is also a very large amount of multifamily housing being built. Seattle is by no means perfect, but *the city has grown by a third*, and was able to do so via mostly multifamily in the small areas, which is more than most American cities can lay claim to.

        The small area restriction had the side effect of massively increasing the share of commuters who use active modes to get to work, since nearly all the growth occurred in downtown and adjacent neighborhoods.

  3. tompw

    I did a quick check of some modern condo towers in Toronto, and 7-8m seems the norm. Toronto has some (low) requirements for multi-bedroom units, with the general consensus being its insufficient.

    • Alon Levy

      The residential high-rises in Tel Aviv look like they’re around 30*30 m, which translates to a ratio of 7.5 m, with four directions of windows rather than two as in the euroblock. Vancouver high-rises are a bit smaller and Los Angeles high-rises are a bit bigger, the latter coming out of California fire codes forcing larger cores (source).

  4. Richard Gadsden

    I live in a modern-build (early 2000s) euroblock in Manchester UK, so they do still get built. They’re a really good urban form.

    The inner courtyard is a car park, rather than a garden, which means there’s a real shortage of green space. 900 sq ft two-bedroom would be a bit small if I had kids, but I don’t, so it works well for a single adult or a couple. I tend to the view that the best approach to families is a maisonette (two-level apartment) rather than trying to build a three or four bedroom on one level.

    I can’t insert images here, but here’s a Google maps link:

    https://www.google.co.uk/maps/@53.4680133,-2.2477393,158m/data=!3m1!1e3

  5. Eric2

    I’ve been trying to think what the limiting factors are in terms of density. Of course nearly any density is theoretically possible (see Kowloon Walled City) but I am talking about desirable places to live.

    It seems to me the main limitations are sunlight and park space. I think that at densities higher than ~30000/km^2, many apartments do not have reliable sunlight in the windows, and most people would find this unacceptably depressing. This is the case whether you are building towers or blocks – there is a given amount of sunlight per land area, and the choice of building type just shifts which areas are in shadow but does not change the amount of shadow.

    Similarly once you get to these densities, parks tend to get very crowded on weekends and similar times. Towers allow for more ground space to be used as parks (though in NYC for instance this ground space is often wasted as ornamental gardens), but only marginally.

    Car parking and access is a question easily solved by putting parking underground, making streets very narrow, and providing quality transit for most trips.

    This ~30000/km^2 limit applies to all residential areas, however it does not apply to offices and hotels, where people do not demand sunlight, and demand less park area. So downtowns can be filled with office/hotel skyscrapers and become urban canyons and that is OK. But the same would not be acceptable in a residential area.

    Luckily ~30000/km^2 is more than dense enough to house the first world’s population in cities with their current footprints, no higher densities are needed.

    • Alon Levy

      You can go way higher than 30,000. The high-rises on First and Second Avenues on the Upper East Side are, in their footprint, more than 100,000/km^2, with bigger apartments per capita than anywhere in Europe (the citywide average is 50/m^2, the Upper East Side is higher because it’s wealthier, and the only two European countries > 50 are Denmark around 53 and Luxembourg at 66).

      I’ve tried working this out from first-ish principles with euroblock design, with 20 m depth, no traversant apartments, and one giant courtyard per block. You can plausibly get up to around 25-30 floors while still having plenty of sunlight – the ratio of building height to courtyard width in that case is still only about 2:1, which is about where some of my Berlin and Paris examples are. You end up getting something like 200,000/km^2. The main limiting factor on this building typology is that the smallest scale this can be done is one quarter of a block, so 30,000 m^2 of built-up area and around 250 apartments, so only a handful of huge realties can build it, and for better efficiency you want the entire block so that the elevators at the inner corners are redundant with one another, so 120,000 m^2 of built area and 1,000 apartments.

      • Eric2

        My cousin’s parents used to live on the Upper West Side until dying recently, now my cousin sometimes visits their old apartment (pre-covid) and plans to sell it. The apartment is one floor up from the street. My cousin says he would find it very depressing to live in such an apartment permanently, due to the lack of light. Just one data point, but if you look at the street widths and sun angles in winter, I think it checks out.

          • Eric2

            It’s in a midblock high-rise. But shouldn’t be more relevant what the building *opposite* it is? That building is a typical 4-5 story brownstone. The gap between the buildings is ~15m.

    • michaelrjames

      @Eric2

      We’ve had more or less this discussion before:
      https://pedestrianobservations.com/2020/05/29/a-bigger-city-is-a-better-city/#comment-78373

      It seems to me the main limitations are sunlight and park space. I think that at densities higher than ~30000/km^2, many apartments do not have reliable sunlight in the windows, and most people would find this unacceptably depressing. This is the case whether you are building towers or blocks – there is a given amount of sunlight per land area, and the choice of building type just shifts which areas are in shadow but does not change the amount of shadow.

      Both you and Alon get this wrong. It’s not the density per se but the building form that affects light levels, especially at street level. Alon is ignoring the street and also the lower level apartments in a tight hi-rise district (at least part of the reason why value of apartments rise with each floor). The fundamentals were worked out several centuries ago–even if US cities wish it away under pressure from developers. Eric2, your concept of sunlight only applies to a small time window around midday on the summer solstice; at all other times of day and season, shadowing matters and the height and nature of buildings does affect things especially at lower levels.

      http://www.citylab.com/housing/2016/12/how-the-battle-for-sunlight-shaped-new-york-city/510917
      How the Battle for Sunlight Shaped New York City
      As the city reached for the sky, those down below had to scramble for daylight.
      LAURA BLISS, 18 Dec 2016

      It also affects the health of parks and street trees though I don’t know if this is the reason why there are so few trees on the streets of Manhattan.

      Similarly once you get to these densities, parks tend to get very crowded on weekends and similar times. Towers allow for more ground space to be used as parks (though in NYC for instance this ground space is often wasted as ornamental gardens), but only marginally.

      Both these statements aren’t evidence-based but are what one might think are logical conclusions. However neither are true. Parks in even the most dense cities are rarely crowded. They tend to be crowded only when special events are organised in them (and people tend to remember this). For many years I routinely spent some time on Sundays in Jardin du Luxembourg which is one of the most popular parks in the middle of one of the densest cities in the world. Of course there were always plenty of people but almost never crowded. The other popular parks like Montsouris, Monceau, Buttes-Chaumont had fewer people though always popular on weekends, especially Sundays. As for the big parks like Boulogne, Vincennes or NYC Central Park, they can swallow huge numbers without being crowded. Even Kowloon Park in the densest part of the densest city in the world. Perhaps the only parks I remember being somewhat crowded (I’d remember because I don’t like crowds) are in Tokyo, like Meiji; this is because it is of special significance and is in the biggest city in the world with a serious shortage of parks. So, sorry but you are simply wrong.

      This misconception about parks and their usage is what drives all kinds of crazy planning policy–like over-large parks in dense urban environments or the now completely discredited notion of towers-in-a-park which always turn into people-free, windswept wastelands topped off by usually neglected ‘gardens’. Equally, setbacks or forecourts for hi-rise is also a very counterproductive strategy to try to ameliorate the impact of the buildings height and bulk; they too don’t work and usually produce hostile under-utilised space.

      None of this is to say that one can’t achieve a very high density. The question is what are the pros and cons of the various approaches. If quality of street-level urbanism is a factor then you know which I prefer. Though an aerial view is hardly enough to truly reveal such important things, nevertheless look thru the dozens of examples given by Urban Kchoze and it does shine thru. In fact aerial views are revealing of awful planning choices (or non-choices) in the US, and in fact Japanese, cases–despite the ugliness and amazingly inefficient use of space, public and private, they don’t even achieve anything like the overall densities of low-rise Euroblock cities/districts, not to mention the urbanism that it generates autocatalytically. Curiously the only hi-rise implementations that half work are those of garden-city Singapore and Hong Kong, city-states highly constrained by their geography.

      • Eric2

        I don’t have the stamina to match you in word count, so I’ll keep it brief: you are wrong.

        For a given population density (or more precisely, building volume), I believe the amount of sunlight received by the average apartment is close to identical. (You did not attempt to seriously think about this argument, but rather ignored it.) Choosing towers versus blocks affects the distribution of this sunlight – towers cast shadows far away while leaving gaps down to street level in between, while blocks put the lower floors in perpetual darkness while leaving the top floors with constant light. But there is not a clear advantage to one or the other.

        As for parks – for the last decade I have lived in an area of density ~20k (very rough estimate) with a higher park density than Paris. Every weekend with pleasant weather the parks here are crowded – by which I mean mostly full of picnicers every 5-10 meters with not much room for ball players. They are also full on weekday afternoons – though more with ball players who require more area per person. From what I hear, Central Park in NYC is similarly crowded. If Paris is not, maybe that’s because many units are owned by rich foreigners living abroad, or by old people who don’t get out much. Anyway, if my area wants to increase population (as is being discussed), there will be pressure to increase park space by creating superblocks without surface car traffic/parking (which is great). They will also need to avoid wasting land area on useless roofs when the same area could be provided at ground level for public use, just by building taller buildings.

        • michaelrjames

          @Eric2

          The fact is that cities have building regulations about height versus shadow, and usually special rules about overshadowing parkland. I might even post (separately) the earliest law from 18th century Paris. What happens in the US (and Australia) is that the rules keep getting relaxed. You may believe that is due to …. better understanding of … shadowing …. or something magical. I’ll take the more obvious one of pressure from building speculators. I’d bet Trump Tower involved such relaxations, though I think at some point, well before those super-talls throwing their shadows deep across Central Park, regulators and politicians simply gave up.

          Parks get crowded very occasionally but it is rarer than you say or think. What you appear to be describing is deliberate crowding behaviour by a subgroup of park users. I find it curious that your crowded parks still manage to fit in a ball game! It seems we have different definitions of crowded. (I suppose on that basis we both could be correct.) The thing is that you could provide more park space and it would not change this phenomenon–in fact it is my argument against one big park like Central Park.

          Also, your argument was that towers provided more space for more parks–which is the discredited theory behind towers-in-a-park–but I think you’d find cities with tall towers have less park than those without. Or at least parks that are usable or in fact used. The notable thing about those pics from Urban Kchoze of medium- or hi-rise, including barrack-style housing, is the complete lack of people in any of that “green” space around them. Here is an extreme case:

          Also re your cousin: The apartment is one floor up from the street. My cousin says he would find it very depressing to live in such an apartment permanently, due to the lack of light. He hasn’t even lived in the apartment! This is the sort of thing I am talking about: people imagining all kinds of things. Without evidence, if very human.
          I’m saying that the worry that the local park will be crowded out due to the high density of residents (not to mention those zillions of tourists in Paris, or for that matter Manhattan) is unfounded. People are funny in that they will often choose to crowd when they don’t need to, but curiously for people like me who don’t like crowding, such parks usually and most times (even ‘crowded’ Sundays) there are still plenty of uncrowded areas–indeed usually the majority of such parks. I almost always had exclusive use of seating overlooking the tennis courts at Jardin du Luxembourg (which, btw, were not as intensively used as one might imagine in such a dense city … I suppose it is just those lazy unsportif Parisians only interested in hanging around bars). Another example comes to mind: the promenades on Pont Neuf often do get fairly crowded but curiously just meters away is the delightful Place Dauphine (the tiny triangular park at that end of Ile de la Cité) which is usually empty. The same was true of Ile St Louis which has a residential density of about 44,000/km2 yet I always found Square Barye, a tiny park at its eastern tip, to be a refuge of calm.
          The common bleat of suburbanites is that they much prefer their ‘wide open spaces’ and more accessible nature etc to the crowded city, yet actual studies and data shows they use such space much less and in fact walk and exercise much less.
          I think your post actually proves my point, but that’s a perception too. Perceptions, whether evidence based or not, are powerful things.

          • Eric2

            Once again you go on rants about tangentially related topics (like what the shadow laws were 200 years ago, or anecdotal stories of individual projects that failed to use their land reserves well) rather than actually addressing the topic. And as usual, your opinion entirely comes down to your idiosyncratic ideas of what is “aesthetic” to *you*, not what *people in general* actually would choose to or enjoy living in…

          • michaelrjames

            @Eric2

            My final word.
            What I wrote was precisely on topic. True it is my opinion (what else?) but also happens to be shared by those who make Paris and France the most visited city & country in the world. Many comment about what makes Paris so beautiful but many also miss what is in their faces, and it’s not that tower or the Louvre …

            I cited 200+ year old law because it seems they almost discovered a physical law which are immutable over time. Of course you are free to take the Star Trek view of life.

          • adirondacker12800

            complete lack of people in any of that “green” space around them. Here is an extreme case:

            It appears to have been taken in winter. There are a few deciduous trees in the upper right. They are bare. People don’t spend a lot of time outdoors when it’s freezing out.

          • Andrew in Ezo

            @adirondacker12800
            Exactly. I am familiar with the neighborhood as it is in a relatively newly developed suburb of Sapporo (where I live)- hence the relative lack of planted vegetation. Picture was likely taken in early spring judging by the color of the grass and patches of leftover snow. Could have been too cold out, or taken on a weekday. The area (Ainosato) is very suburban single family dwelling and auto-oriented, so the parks would primarily be used by children, not the couples and gaggles of frisbee-throwing millenials you imagine in places like Central Park or other urban oases. The few adult singles or childless couples living there would either drive somewhere or hop the train to go to the city for their leisure time.

        • michaelrjames

          Here’s that early interpretation of building height law that I promised. (Even if you don’t have the stamina to read such verbiage …. Sorry, couldn’t help the snark.) I think it is both true and useful in understanding the almost universal perceptions of Paris. Incidentally I think the same is broadly true for Washington DC for the same reasons (of course they are both French cities!). This combination of height and street width etc does not produce a sense of oppression at street level (or anywhere else) which is not what one might imagine from being made aware of residential density or building form (built right to the perimeter). Norma Evenson (in Paris: A Century of Change, 1878-1978) describes the changes to these rules from the 18th to 20th century, that allowed the number of storeys to increase up to a potential 8 or 9, but by extending the rules regarding setbacks at the top –often squeezing in 3 mansard floors; this is the case for Hotel Lutetia which was built at the peak of Belle Epoque (and remains the only Palace-grade hotel on the leftbank) and has nine floors. In this case (of Paris) the regulators were correct: the stretching of the rules did not impact the original intentions of almost two centuries earlier. The same cannot be said of NYC or many cities that have gone to hi-rise residential. In this case, of perceptions by humans of air and light etc, remain as true 3 centuries ago as today even if some are in denial, or more charitably are unaware of what makes Paris almost uniquely attractive to walk around.

          One can try to make the case for hi-rise to (try to) satisfy high demand but the curious thing is that almost nowhere does it work that way. Patches of Manhattan may be marginally denser than Paris (though not really: UES has 219,920 (2010) on 5.23km2: 42,100/km2; in fact contrary to perceptions the UWS–with much less hi-rise–is denser at 214,744 (2010) on 4.9 km2: 43,800/km2; Paris-11 with 152,500 in 3.7 km2 is 41,600/km2). Moreover on aesthetic and urbanist grounds it definitely doesn’t work. Further it doesn’t make it any more affordable (think: those supertalls are the most expensive in the city though I read recently that the developers and the city only plan on one in three apartments to be occupied at any time).

          The modifications in building regulations effected in 1902 also involved the question of height (figure 97). In 1783 a royal ordinance had stated that “the excessive height of buildings is prejudicial to the wholesomeness of the air in a city as large and as heavily populated as Paris.”40 At this time an attempt was made to regulate building height according to street width. The regulations were modified in 1859, continuing to relate height to street width and extending control to courtyard frontages. Depending on the street, maximum building height could range from 11.70 meters to 20 meters.
          The 20-meter maximum was maintained in the regulations of 1864, which permitted such a height on streets 20 meters wide or over, providing that the number of stories above the ground floor excluding the attic level, was limited to five. Counting floor levels as Americans count them, this would give the building seven stories, representing the maximum practical height in an era before elevators came into wide use. Subsequent legislation in 1872 included regulation of courtyard sizes. A building 20 meters tall required a courtyard of 40 square meters, and no building could contain courettes (air shafts) of less than 4 square meters.
          In 1880 the prefect of the Seine set up a special committee, chaired by Jean Alphand, to revise building codes. The resulting height regulations, decreed in 1888, established maximum heights corresponding to four categories of street width, and ranging from a permitted height of 12 meters on streets of 7.80 meters and below to a maximum of 20 meters on streets 20 meters or more in width. As official street widths were measured between building lines it was possible, on narrow streets, to obtain a wider measurement, and thus greater height, by setting the building back from the street. Most building, however, continued to be built up to the limit of the lot line. Although the maximum height of the cornice line remained at 20 meters, an increase in the height of the attic story above the cornice was made possible. Previously this story had been contained within the envelope of a wall sloping away from the street at a forty-five degree angle plus a horizontal roof, with the attic adding 4 to 5 meters to the height above the cornice. The 1884 regulations, however, specified that the profile of the attic story be determined by the arc of a circle, of which the radius would be equal to one-half of the street, with the maximum radius of such a circle established at 8.50 meters. The effect on building of the new code was to increase the overall possible height on wide streets from 25 to 28 meters.

  6. Frederick

    The developed Asia has a lower latitude compared to Europe, so sunlight is seldom a scarcity in Asia. One must ask how this affect their city forms.

  7. Alex B.

    The big difference here between the European examples and the North American ones seems to be the fire codes – yet there’s no discussion of that in either article.

    Here’s a sketch of the key difference: https://twitter.com/alfred_twu/status/1216764830054436864?s=20

    The end result is that the ‘obese’ buildings have internal corridors with access to multiple exit stairs, where the narrower buildings have multiple cores with just one stair (and notably, most of the examples pre-date any elevator mandates for accessibility).

      • Alex B.

        Yes, there’s quite a bit of variation even within North American (and just US) cities.

        That said, I think the general observation still stands. Almost all of the examples cited as ‘obese’ buildings are double-loaded corridors. The requirement for access to an additional stair is a big reason why you get double-loaded apartments instead of apartments that span the entire building. I’m quite certain that differences in fire codes are the predominant driver of the different form.

        The example from Let’s Go LA is all about high rise buildings, but these examples are mid-rise.

    • Sascha Claus

      Given that Europe is not a country, but a collection of them 😉 and fire codes are made at country level (or maybe even below), that would be big discussion.
      German fire codes require (IIRC since the 1990ies) an additional staircase in residential buildings higher than 30m (and all schools, kindergartens, elderly care homes etc. even when lower). In buildings below 30m (including new construction as well as about 99,999…% of all legacy housing), the fire brigade’s ladder is deemed sufficient. Note that about 99,99…% of all housing predates that law and retrofitting all that with fire exits would be impossible, prohibitively expensive and take forever, so the fire code had to work with that.

  8. James S

    Would be interesting to compare with Brazil. Cities have more apartment high-rises than probably anywhere else in the world. But theyre much skinnier than American ones, so you get more windows, since theres more corners, or they go straight across.

    Its very rare to have an apartment bathroom with a window in the US. Common in Brazil.

    • michaelrjames

      @James S

      The extreme version are the so-called snowflake apartments in Hong Kong. It’s curious that this type of plan is considered inefficient in much of the world but is (or used to be?) common in Hong Kong where land is the most scarce resource of almost anywhere. In essence they are almost a series of independent towers that converge around common elevators & services core. Perhaps it’s the heat and humidity, combined with cultural factors that value windows on all rooms. Perhaps also less reliable electricity mains supply in the early days of such development. In a way these are an adaptation of historic asian courtyard houses, hutongs even!

      http://www.skyscrapercity.com/showthread.php?t=1762858
      Having a lot of facade compared to the floor plan size is sometimes considered as uneconomical, but perhaps there is a building code that requires all rooms to have a window or something.
      The design makes efficient use of small land sizes to maximize the number of units per floor. There are also building code and cultural elements that force builders to design kitchens and bathrooms with windows. If they remove these light wells, they need a wider land footprint to squeeze in as many units.

      like this:

      and this:
      https://www.skyscrapercity.com/threads/snowflake-shaped-floor-plans.1762858/#lg=attachment_xfUid-3-1607413769&slide=0

      • Henry

        Couple of things here:

        Washers are common but dryers are extremely uncommon in HK. So you need a good amount of window/balcony real estate to hang your clothes to dry.

        Hong Kong has regulations WRT building massing, banning particularly wide masses of buildings. This is because Hong Kong’s labyrinthine street network combined with the nearby mountains severely restrict airflow in urban areas, resulting in very high levels of roadside air pollution being trapped amongst the tall buildings. https://www.cnn.com/style/article/hong-kong-skyscrapers-with-holes/index.html

      • James S

        Great example, from my experience, Brazil also has a lot of towers with that kind of shape. I like the floor plan, because it shows that you can have multiple emergency staircases with that shame, you dont need a long rectangle.

        Henry makes a point about dryers. True in Brazil as well, theyre rare. Sam with A/C. So having windows push air across the unit is valuable.

        • Henry

          AC is definitely not rare in HK; in public areas in summer, depending on your disposition you often have to bring a jacket, because for whatever reason malls and MTR crank up AC to be downright chilly.

          That being said, AC is not central, but rather each room has a wall-mounted unit.

      • Jarek

        One thing about the snowflake floor plans is that while larger external surface area per volume allows for more windows and ventilation, it is also less efficient to heat than plain rectangles since there’s more outside walls. Not a huge concern in Hong Kong or Brazil, but it would be a bit of a factor in colder places.

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