Building for Wealth, and Point Access Blocks
The biggest housing activism push in North America right now has moved on from YIMBYism to housing reforms to allow single-stair mid-rise buildings, called point access blocks. My off-hand reference to this last post ended up being the main issue debated in comments; this compounds a post by Matt Yglesias from November that I’ve been meaning to respond to, since he starts working off of some examples of double-stair buildings on corridors in an even older post of mine about the Kowloon Walled City in My Backward (KWCIMBY) meme. I strongly respect the main point access block activists pushing the issue, like Stephen Smith, so I’d like to revisit the KWCIMBY post and explain what I’m doing there, while also pushing back against some of the more iffy claims portraying point access blocks as not just more efficient but also inherently better for families. In short, both forms of housing are generally easier to build in a more affluent society with higher expectations, and some of the comparisons come from that.
What are the point access block and double-loaded corridor?
An apartment building can arrange its apartments on each floor in one of these ways. The KWCIMBY post assumes double-loaded corridors, as in the diagram below:
In each of these buildings, there are two staircases, as required by American and Canadian law; the first building has scissor stairs, forbidden in most of the US but allowed in New York, whereas the second separates the two staircases into opposite sides of the corridor. Apartments are on both sides of the corridor, with one aspect of windows except the corner units, hence the term double-loaded.
This building form is practically unheard of in European apartment buildings. Only one staircase is required per building, so architects instead slice the buildings into thinner pieces, with one staircase and an elevator and apartments radiating from the common area, called a point access block:
Each of the four access points has an elevator and a staircase; the first example has four apartments per floor, with one aspect per unit, whereas the second has two, with two aspects, both north and south. The result is more elevators and staircases per net floor area, but less corridor area; the floorplate efficiency is notably higher, 92.5% in the first case and 94% in the second case, compared with 89.5% in the first case of the double-loaded corridor and 86.67% in the second. This is one of the reasons Stephen is so focused on elevator costs.
All four buildings are 20 meters by 80, except the last, which is 14 by 80. 20 meter wide residential buildings are more or less unheard of in Central Europe – I see a few that are 18, in what look like higher-income neighborhoods to me. In contrast, 14 is standard in Central Europe, with some buildings looking like the above diagram, and others, almost always older ones, having wings that are still around 14 meters wide but end up with an area-to-external-width ratio of 8-9 meters, rather like a 16-18 meter wide building without wings. In practice, on a 100*100 block, we’d never have two buildings looking like an equal sign but rather an enclosed rectangle, with or without wings.
What about the single-loaded corridor?
A third housing typology puts all apartments on a corridor, but only in one direction. The corridor is then in the open air, and apartments have windows on both sides, to the corridor and in the opposite direction. I lived in such a place for a year in Berlin. This is not unheard of, but still rare. The width of such buildings is limited by the need for apartments to stretch all the way, limiting them to at most 14 meters and usually less.
The resulting floorplate efficiency is low, which turns this into a question of how much cheaper it is to build an external corridor than an internal one. When I asked on Bluesky, I was given ranges for the answer, from an external corridor being 25-50% cheaper to its being if anything more expensive. Temporary worker housing tends to use this form because it is built to lower standards, in which the external corridor is just some barred steel without protection from the elements above, which should reduce the cost of the corridor. This form still exists in permanent housing, with concrete corridors that offer protection from rain, but it’s less common than the other two.
Point access blocks and families
The biggest selling points of the point access block are that it has better floor plate efficiency and that it permits units with multiple aspects to allow for cross-ventilation and for strategic placement of rooms (living room facing the street, bedrooms facing the quieter internal courtyard of the euroblock). This is bundled with other issues, at the same time:
- In Europe, buildings are almost never built out of wood, and if they are, it’s usually mass timber. This means that the cost of construction is proportional to floor area, largely linear in the number of floors for a given footprint. North American construction uses light wood on a concrete podium, sharply limiting height to six to seven stories, hence the preference for thicker buildings to increase floor area. In turn, light wood is less safe in fires – but those codes don’t exempt concrete buildings from the two staircase requirement.
- The double-loaded corridor has units so deep that bedrooms come with their own bathrooms and walk-in closets. Absent these, the maximum usable depth of a bedroom is about 6 meters. Bathrooms cost more to build per square meter than bedrooms and living rooms, which drives up construction costs.
- The double-loaded corridor makes it easier to build units with fewer bedrooms – it’s just a matter of how much corridor width the apartment takes, so costs are linear in the floor area of units. The point access block instead prefers larger units, in square meters, since larger apartments have higher floorplate efficiency, and it’s routine to build a cheaper three-bedroom, one-bathroom unit.
The last two points have been used by some urbanists, especially more conservative ones, to argue that the point access block is inherently family-friendlier. The argument made by Mike Eliason (who’s not at all conservative) is that Seattle, where he’s based, builds multifamily housing rapidly but all of it is studios and one- and two-bedroom units, on the expectation that families with children should eventually move to the suburbs.
More conservative people even relate that with low urban American birthrates, which always comes off as strange to me given how low European birthrates are. The one developed country with above-replacement birthrates, Israel, doesn’t use any of these forms, but instead has independent buildings, some mid-rise and some tall – and there’s consensus among European and American urbanists that tall buildings are bad for families. At any rate, the Israeli sociologists I read on the subject, like Sergio Della Pergola, attribute Israeli birthrate exceptionalism to other issues than built form, just as Singapore’s Paulin Tay Straughan attributes the very low birthrates in rich Asia to other issues.
The difficulty of relating the issue of housing forms with that of apartment sizes is that housing a family requires a lot of apartment space to go to people who are not working, because they are children. If housing is expensive due to high construction costs, restrictions on building, or both, then housing will be built for the rich, which means not just high-income earners, but also households with a high income per person, which are almost always ones without children. A developer building a double-loaded corridor making a choice between a one-bedroom, say 6*9 meters, and a three-bedroom, say 12*9 meters, will choose the former if two independent households can outbid a family. This is getting to the point that in urban America, it’s normal for unmarried adults to live with housemates, because there are a lot more three- than one-bedroom apartments in cities that don’t build much housing, like New York or Boston.
The family could outbid the single person, but not in all circumstances. A two-income family can do well, and the working adults are likely to be older than the single person and thus higher earners. A landlord of a fixed apartment choosing who to rent to would also prefer the family to the group of three to four housemates – the family is more stable, divorce being far less common than housemates leaving with little prior notice. But not all families have two earners (and the social conservatives who are most anxious about family housing tend toward one income, not two), or two middle-class earners, and so far American developers haven’t yet run out of demand for single people and childless couples to build for.
Point access blocks and wealth
In a way, the point access block has benefits that aren’t yet unlocked in Europe. Higher wealth is spent on, among other things, bigger dwellings. The double-loaded corridor in a way bakes in assumptions of private bathrooms, essentially spending income on higher-cost elements. But it’s possible to do the same with a point access block. The point access block ends up more efficient when apartments are bigger, because it’s limited by number of units per floor, and the bigger the units, the smaller the proportion of the unrentable common areas.
Speaking of common areas, higher wealth doesn’t necessarily demand of them. If the expectation is that people should have a washing machine and a drier at home rather than in a common area, then the demand for such an area shrinks. Trash rooms take up more space, but then higher wealth, as opposed to higher inequality, means not just that the demand for trash rooms is higher but also that the supply of workers to staff them is scarcer, and at the end of the day people can just haul trash bags to a collection point in the courtyard or a side room on the ground floor. Trash chutes are an innovation that doesn’t take up common space (for one, they can be installed in-unit, especially if there are only two units per floor anyway). High-end condo amenities like private gyms are usually provided at the scale of an entire building rather than a floor, and a complex of interconnected buildings is likely to have just one either way.
In the examples I posted above, in a way I baked in a wealth assumption, in that the option with two units per access point assumes those units average 132 m^2, which is very high for Europe; the norm for high-end buildings here is three units, with slightly lower combined floor area than 264 m^2, and the same or a hair higher circulation area to allow for a third door, with the smaller apartment usually only having one aspect of exposure. A 132 m^2 unit, in effect 10*14 with slight recessing at one end, would generously have four bedrooms, likely configured as three actual bedrooms and a private office or guest room. The intended users would be families of means, but then again new housing tends to be built for this class, and over time, growth and abundance make the standards that today mark middle-class wealth more widespread across classes. The working class once didn’t have indoor plumbing.
Pedestrian Observations 
Housing is definitely scarce in Hong Kong as well, but we don’t observe market diversity being affected very much. It’s common to see studios and 1-4 bedroom apartments being mixed in one single estate. There was a period that apartments are growing larger and larger therefore government was considering restricting maximum unit sizes; but soon developers found small units more profitable thanks to the shortage.
Is mid rise timber building even a good idea in the US, with hurricane, tornado, flooding, fire, and other disasters occasionally hitting different parts pf the country
Except for fire and flood building material is irrelevant – and both of those tend to give you time to get out if there is a problem. Engineering can make wood strong enough for the job. Wood is cheap, strong, and works very well. This isn’t the three little pigs, this is real engineering. When you look at a building like an engineer bring and cement start to look very bad – they are heavy and weak in compression (which is why nearly all buildings are steel framed). You can get a cement/brick building slightly taller than wood, but not much before the weaknesses start to show (which is why large buildings are steel frame – there might be brick but it is decorative.
In the case of earth quakes (which is a big deal in California) wood is better than brick/cement. You get warning to evacuate in case of fire and so you live to rebuild. Earthquakes don’t get nearly as much warning and so if you building fails with you inside you die. (steel again is good).
Brick buildings do last a lot longer than wood buildings in general. Most of our poorly built late Victorian brick houses are still standing.
There are a lot of wood buildings from the Victorian era standing in the US. And because wood is more flexible to remodeling than brick they are more likely to have been updated several times over their life to meet the needs of whatever was modern to the then current owners. Now you are correct that wood doesn’t last as long (unless you are in a desert – but then you have to import it), but it still lasts long to outlive its reasonable usefulness.
There are a lot of former brick buildings no longer standing in the world because they outlasted their usefulness and were torn down.
There is a good argument that every building built before 1985 (only 40 years ago!) should be town down. Modern insulation standards are much better. Modern kitchen standards are very different. Modern wiring is different (no phone lines in walls, but maybe network jacks; likely more outlets per room …). This also gets us out of lead drinking water pipes. some of this is retrofitable but only in a major remodel where you are not far off from starting over and starting over allows floor plans not possible. Of course this is expensive enough that most places wouldn’t do this, but Japan proves it isn’t unreasonable.
Definitely there is an argument that the pre cavity wall houses (i.e over 100 years old) should come down, but everything since then can or has been sensibly retrofitted to give you modern advantages anyway.
There are only so many things you can retrofit without tearing down though. You are often stuck with walls that cannot move and so you can’t adjust space the way you might want to.
Of course this does depend on money. I know one area where tear and and rebuild ends up being illegal and so people will instead tear down all but one outside wall thus staying in the remodel category while changing everything. (this is mansions where a bedroom can be as large as my entire house). It would be cheaper to tear down, but the laws don’t allow that so they find their cheat. They are also doing this a lot more often than I’d propose a tear down (but Japan will do the tear downs about as often)
If you would consider that level of renovation you are either a builder or very wealthy or the building is genuinely life expired.
they are heavy and weak in compression (which is why nearly all buildings are steel framed).
You are 100% incorrect. Today, most mid rise and taller buildings are made of concrete not steel because concrete is so much cheaper and flexible than steel. Getting major steel members for a high rise (hot rolled “jumbos”) can take months or a year in the production queue, but the local concrete plant can give you concrete to start pouring with a week’s notice, and if you are building a taller building with thicker columns and beams they just send more trucks until the pour is complete.
Concrete is not weaker than wood in compression, it is exactly the opposite, concrete is stronger in compression for the same reason that you can pile more weight on a rock before it cracks than you can on a piece of wood before it splinters. Concrete is weaker in tension than steel – it is easier to tear concrete apart. This is why all modern concrete is steel reinforced, the steel rebar inside provides the tension strength that concrete does not have naturally (in some intense cases like critical sheet walls the rebar is so thick the structure looks more like concrete reinforced steel than steel reinforced concrete). Modern material science and engineering have made incredible strides all the last few decades allowing buildings of any height to be made out of concrete, as opposed to say the 1930’s when only steel framing could build a high rise.
Steel is used more often for the highest structures, but there are no limits to what concrete can do. Note that many concrete buildings use steel for the upper levels/spire/roof (where its lower weight is an advantage higher in the structure but huge steel beams are not needed because the load is lower); many modern buildings are also composite with a concrete core and columns (to carry the weight downward because concrete is good in compression) but steel beams and outriggers (to carry the weight across spans and for shear strength because steel is better in tension).
You can get a cement/brick building slightly taller than wood, but not much before the weaknesses start to show (which is why large buildings are steel frame
“Slightly” taller?!?!?!?! The Burj Khalifa, the – checks notes – tallest building in the world is concrete framed up to 606m which is taller than every building in the world except for four, and taller than any building in any continent except for Asia.
How embarrassing – I meant strong in compression weak in tension.
Reinforced concrete counts as steel buildings as much as concrete as that steel is what makes them possible. They do use less steel than steel beams, but that steel is still critical to how the system works and so not at all related to concrete construction which is limited to much lower buildings.
No one considers reinforced concrete buildings to be a “steel building” just because there is rebar in it. By that standard every building with steel beams should be considered a “concrete building” because each and every single one of them use concrete foundations. As I noted, there are true composite buildings that use concrete for some members (principally columns, shear walls and cores) and steel for others (usually beams and braces).
Un-reinforced concrete is hardly ever used (even sidewalks are poured with a metal mesh inside them) so concrete construction as you define it basically doesn’t exist, certainly not for any building. This makes your definition not relevant. To every person in the world involved in architecture, engineering or construction, a concrete building is clearly defined as a steel reinforced concrete structure with cast-in place columns and slabs or prefabricated panels. These concrete buildings are clearly distinguished from steel buildings that use hot or cold rolled steel columns and beams to carry the building loads, with non-structural concrete deck infill. Engineers look at these concrete buildings very favorably, and do not in any way compare them to brick or cinderblock buildings; concrete buildings are strong enough to build any structure that humans want to build right now. Developers and contractors look upon them even more favorably since concrete is cheaper, more flexible and quicker to procure than steel framed buildings for most purposes.
In New York, reinforced concrete is used for residential multi-family/apartment builds to all kinds of heights. Steel frame with concrete deck infill is used for commercial of all heights. Warehouses, self storage (4-6 floors generally), retail are steel frame, not concrete. So I would differ on your comment about steel is used more often for higher structures.
I can’t remember a single such disaster affecting a mid-rise timber building in the US. (In contrast, there was that concrete high rise which collapsed in Miami, the 9/11 terror attacks destroying steel skyscrapers…)
There are many reports of mid-rise timber buildings completely burning down during construction, before the sprinklers are installed. But once installed, the sprinklers appear to make things very safe.
Eric2,
There have been instances of mid rise timber buildings burning down completely after construction too. Sprinklers make this much less likely but not impossible. In most cases if the building is modern and has sprinklers then everyone gets out safely.
Forms of residential buildings in Hong Kong are shaped by laws and regulations, including but not limited law on effect of buildings against sunlight and air circulation and various rules related to FAR etc
But regulations in HK won’t result in spaces being wasted on unsoldable corridors.
With regards to bathrooms people like having lots of bathrooms these days. I think that is OK.
I don’t think they have to be particularly expensive either.
I also don’t think a three bed apartment should be twice as big as a one bed. The communal spaces like the kitchen, the living room and perhaps dining room take up a fair amount of space.
You should be able to have a 3 bed apartment in ~80sqm, a modern British 3 bed house is maybe 90sqm and an older 3 bed might be 100sqm. And houses lose maybe 10sqm for the stairs.
Compared to a closet of the same space the bathroom is very expensive. Even a bedroom with much more floor space is probably cheaper to build despite the required window.
You need to provide air ventilation or mold will grow (a closet needs some but not much).
You need plumbing, and since drain water universally gravity flows downhill that means the rest of the whole building below needs to be designed so that those pumps have enough slope for the water to flow. Don’t forget that running water makes noise which will annoy those tenants below so provide some sound proofing for those pipes. Also there are probably fire codes about things going between units, check what that means for your pipes. Again, anytime you have plumbing the entire building design below needs to account for that.
You also need to pay labor. Plumbers costs more than most other labor and you need them.
If you can get by with no bathroom (or shared bathrooms like a dorm) that will save a lot of money. $10000 per unit is a lot of money to any project. Sure it might not look like much, but those costs add up and accountants track them.
@henrymiller74 you are correct, despite what Matthew Hutton might think, bathrooms are expensive. Your cost of $10k per unit is more in line with just a bathroom remodel though, building a full bath is generally thought to cost as much as a mid-size sedan.
Probably $15k for a remodel including ceramic tiles these days, but even so I find it difficult to believe adding an extra bathroom would be much more than that in a new build. No disposal time/costs in exchange for the extra work to put the necessary pipe work in seems a reasonable exchange. Pipework isn’t expensive at the builders merchant.
Pipe isn’t very expensive but paying a plumber to put it in is. Also remember that when building a new bathroom you are not just putting pipe in the actual bathroom, you also need to put in pipe through the floor and walls to get to the waste and vent risers. Depending on layout of other plumbing you may need to add risers. In most places bathrooms require forced ventilation to prevent mold and circuit interrupters to prevent electrocution so there are electrician and mechanic costs as well for new bathrooms. Demo by comparison is cheap, a couple people can remove all fixtures and cabinets from a bathroom in an hour, maybe more if the flooring comes out or drywall removed from the walls.
@Onux, I am sure if you have two bathrooms per apartment (I.e a family bathroom and an en-suite for the master bedroom) that they could be next to each other and share a down pipe, and for the kitchen in the next door flat to share that down pipe as well – or better for them to be mirrored and four bathrooms to share a pipe and two kitchens to share a different one. Agree with a third bathroom it would be trickier and you would probably need a separate down pipe.
@Matthew Hutton,
Yes, and developers and architects work on floor plans to stack bathrooms and kitchens in mid and high-rise development for this exact reason. But this does not help with making new bathrooms less expensive compared to remodels. The riser is only part of the issue, you still need all of the horizontal pipe to get from the toilet/sink/shower to the riser. If a riser is in between two bathrooms the length of drain pipe to reach it in each bathroom has to be longer compared to a riser centered on one bathroom – and more importantly the time for the plumber to install them is longer too. If you are stacking four bathrooms at one riser and two kitchens on another, that is an additional drain/hot water/cold water/vent stack to install compared to stacking two kitchens and two bathrooms and leaving the intervening walls dry. Services (electrical/plumbing/HVAC) is expensive, and new bathrooms are more expensive than bathroom remodels.
I think you are wildly underestimating the time savings from getting to work on multiple bathrooms on the same site while sealant/glue/adhesive/grout is drying. And also demolition and replacing damaged plasterboard/waterboard is harder than you think.
You shouldn’t be *forced* to have an extra bathroom just because there is no other plausible use of floor area without windows.
Whatever the depth of the apartment, point access allows you to make the building footprint larger (=more valuable) for a given apartment depth. If the market asks for super-deep apartments with lots of bathrooms, that is fine. But if the market prefers normal-depth apartments with a larger number of bedrooms, that should be legal too.
I’m not sure if I agree or not. The elephant in the room: fire safety. Does point access really provide sufficient fire safety while being cost effective? If it is more cost effective to build with cheaper wood and provide dual staircases, then building that way and putting in excess bathrooms just to have something to do with the space makes sense.
The above is a question I cannot answer. The issue is complex and may even be could be cost effective but only after many projects where everyone learns something just different enough from how they build that they today are not good.
Concrete point access block costs per m^2 here are a lot lower than American wood double-loaded corridors, around half as high or slightly more than that.
@Henry, @eric, I am sure developers add lots of bathrooms because despite their costs as you highlight quite correctly people like them.
The obvious cheap thing you can add to space that is difficult to use for anything else is storage of course.
People like them, but do they like them that much? What is what are they there because people want them, and what are because you have to fill space with something and only bathrooms or closets can apply? For a poor large family they would want a 4 bedroom apartment, but still with only 2 bathrooms and not too large closets. However the reality of the dual staircase design is you end up with at most 3 bedrooms and 3 bathrooms, many large walk in closets just because it isn’t legal to put a bedroom there. If it was legal to not have a window you could fit 5 smaller bedrooms with 2 small bathrooms in the space of a current 3 bedroom – I submit the poor would prefer this configuration except it isn’t legal. (note that by saying I submit I’m admitting I don’t know for sure – it needs market analysis)
My bedroom is 4m by 3m which is a good sized double bedroom. You can easily go smaller – especially for a bedroom aimed at children. I mean they need a bed that is what 1m by 2m and then a wardrobe that is maybe 1m by 0.5m? So a 2.5m by 2m room would just about work at an absolute minimum – especially if they had one of those bunk beds with a desk under it.
I would have thought the poor would prefer that to having a bedroom without a window.
My en-suite bathroom is 1.7m by 1.7m and is fine.
Hot and cold water is straightforward plumbing. The sewer/drain pipes are trickier because they have to have a slope in the correct direction to operate, and have to have traps to prevent sewer gas backflow.
The slope issue with drain pipes is an issue, and relates to placement of risers (and their associated cost) because for a given floor depth drain pipes may not be able to reach a distant riser with correct scope. Traps are nothing though, they are just a p-shape curved piece of pipe that require no special planning or installation – toilets come with the trap built in for instance.
Hot and cold water piping is not straight forward. It is pressurized piping, which means every joint needs to be a pressure joint (either soldered or special mechanical fittings, not slipped together by hand like drain pipes) and they are made out of copper not cheap PVC. Hot water pipes require thought as to layout so they are not too far from the water heater to minimize wait – in larger mid/high-rise buildings you need to plan for recirculation pumps and loops to keep hot water constantly flowing between the heater and faucets because the distances are so long. Hot water piping can also require insulation in these conditions. In the context of adding bathrooms to a project, more sinks/showers will require more or larger hot water heaters to supply them, which in turn can require upgraded electrical or gas service. Water piping needs to account for water hammer, and in certain locations a water softener system is needed to prevent scale buildup in the pipes.
Large (22mm) diameter copper pipes are $10/m. Like yeah they aren’t cheap, but no they don’t break the bank either.
Narrow copper piping is $5/m.
https://www.screwfix.com/p/wednesbury-copper-pipes-22mm-x-3m-10-pack/18384
Pipe insulation is $1.50/m for a 22mm pipe and a little less for a smaller one – https://www.screwfix.com/p/essentials-economy-pipe-insulation-22mm-x-13mm-x-1m-45-pack/57077
You can use pex pipe in commercial and residential buildings, much faster and easier to use than copper. Even if just for non-drinking water, like a sprinkler system, its a big time saver over copper. It’s also cheaper, depending on the diameter, $3 or less per linear meter.
A quick test on how local regulations obstacle affordable housing. Will such floorplan representing affordable housing in HK be banned in the US?
I think zoning patterns, indirectly via economics, is the main reason US developers build small apartments.
Affluent areas close to downtown are where the market demand for mid- & high-rise apartments is. (In outer suburbs, low-rise garden apartments are the dominant multi-family type.) In US cities, most land there is zoned 1-family.
All land is expensive in affluent areas; in large cities it stays expensive even far from downtown. In 1-family detached zones, the land value per housing unit is high compared to the structure value. (For old houses, especially small ones, the structure value is often negative — that’s why there are so many tear-down mansionizations.)
1-family zones limit the number of units per lot more strictly than the floor area. When the land cost per unit is comparable to or higher than the cost of building a new structure, the marginal cost of the first bedroom and bathroom is much higher than subsequent ones. So you see all these 4- & 5- bedroom houses.
In multi-family zones, on the other hand, zoning generally restricts floor area but does not limit the number of units in a structure. So the construction cost is much closer to proportional to the number of bedrooms.
The natural outcome of this economics is to put the small units in high-rises and the big units in 1-family detached houses. Scarcity of land for high-rises accentuates this pattern.
Your comment about trash chutes reminds me of one of failings of Cabrini-Green low-income housing in Chicago. At one point, trash chutes were backed-up 15 stories. Tenants would simply throw their trash off their balcony. Balconies then had chain-link fence put around them, to prevent trash being thrown, or people falling off the balconies, or people being thrown off the balconies.
Isn’t that just a failing to service the building, then? Something could become stuck and obstruct, sure, but if it’s just that the dumpsters are filling and no one’s coming to empty them, that’s the issue.
Poor–or no–maintenance of public housing in the U.S. is one of the reasons people have been so against it.
– Building services are broken because the landlord can’t be bothered to have them repaired.
– Building services are broken because every time they are fixed, some resident(s) sabotage it. Perhaps they think it’s funny.
– Building services are broken because maintenance personnel refuse to go there and fix it because on multiple previous occasions some resident(s) harassed/beat them. Or at least, they demand a police escort.
Given that maintenance frequency and/or cost-per-maintenance are much higher than expected, the question of “how much yearly expenditure, on electricity+maintenance+etc., does it take to keep building service X (mostly) working” may very much turn out to be answered with “more than we can afford”. In-situ abandonment of building services is …rare. It takes an unusual violation of design assumptions to justify this decision. But I’ve heard that some of the projects had problems with keeping the lights on in the public areas, as in, they had trouble replacing all the bulbs and lamp covers that were smashed.
But then, the technology choices used suffered from a lack of graceful degradation. If you live in a 4-floor walkup apartment, and the default way to handle trash is to walk it down the stairs, few (nonzero, but few) people would have thrown it from the window/balcony. This would largely remain true even if there was originally a trash chute, and people have to take the fallback option of walking it. Whereas if you live on the 10+th floor, the default way (the trash chute) is broken, and the elevator is also broken because of course it is broken, it takes a lot of …considerateness, “manners”, middle-class conformity, willpower… to walk an extra round-trip of 10+ stories as opposed to dumping it wherever it may land.
Since you bring that article again, when I read it there were some details that surprised me as a non-architect, thinking about all the places where I’ve been.
“Bathrooms and kitchens with windows are not only expected but mandatory in much of the world, but are almost impossible luxuries in North American apartment buildings“. <- I’m very surprised by this, I think I’ve been in apartments with non-windowed toilets at least in Singapore, Russia, Spain, UK, Brazil… basically the solution is using extractor fans. Am I misunderstanding something here?
“The only way to make these spaces efficient is to drop the requirement that bedrooms have windows. (…) These designs are legal (and increasingly popular) in many American jurisdictions, but are almost unheard of outside of the United States.” <- And in Spain there’s lots of buildings that are very deep and they workaround this by having rooms facing lightwells, which brings ventilation and maybe not much light, but after all the bedroom is for sleeping, you really want your light in the living room instead. I’m sure it’s not the only place with this solution.
Yeah I mean bathrooms definitely don’t have to have outside windows. They do need good fans which can be a challenge but it isn’t impossible.
Bedrooms in the US need windows as a last resort fire escape. If by the time you realize that beeping is a fire alarm it might be too late to safely get to the stairs so you have a window. If it is a second floor window you can probably safely jump hang on the window sill and the fall isn’t too bad). If a fire department sees you waving from a higher window they will rush a ladder to you, but they only have ladders good for around 30-40 meters. Higher than that – well if the fire department knows you are they they will send someone with breathing gear and protection to get you – if that is safely possible; otherwise smoke inhalation is one of the larger dangers of a fire and standing at the window will get you some air to breath (maybe).
I suspect Spanish light ducts act like a draft inducing chimney in a fire and so are the worst thing possible. However engineers can maybe do something about that so if someone can show me real tests I’ll change my mind on them.
Since I’m not an architect, I’ll stick more to the observation than the opinion.
Surely light ducts are draft inducing, because that’s the way to cool down the apartment in summer without air conditioning: at night you open the windows on both sides strategically and the draft brings the cool air inside. I always thought that was by design, maybe it’s a cultural difference in priorities? Or as the IT joke goes: It’s not a bug, it’s an undocumented feature.
Anecdotally I grew up in a small room facing the light well, and privacy was never an issue, I suspect one of the things that are different in Spain because of the endemic external rollable outside window blinds. The only issue was that you had to close the window at meal time to keep out neighbor kitchen smells. It is true that I’ve seen a lot of “inner rooms” in Spain, but I cannot think of them abroad.
When I had to make a big reform, I hired an architect, and fire safety didn’t appear very much in the conversation. The point you make above about the pipes length and slope was quite important for the placement of toilets, so the idea “I can’t use this space, let’s put a toilet” also requires nuance. A toilet too far from the exit pipe requires some extra hardware which I saw going wrong at a friend’s place, so just because you can do it, it doesn’t mean you should do it.
Italy has outside windows in bathrooms, and Stephen relied on Italian standards heavily.
The light wells are common in Old Law Tenements in New York. They’re considered undesirable there – there isn’t enough natural light, and the room faces another building so that if you have artificial light and no curtain then the neighbors can easily see inside.
Garbage chutes are not very nice. I lived–long ago–in a mid-rise in NYC that had one. Smelly and a pest route to upper floors.
Today, with required sorting of garbage, trash and 2 types or recyclables, the chute is not practical.
Where I live, in central Europe, appartment buildings usually have one staircase, one elevator and about 4 flats per floor. Buildings are mostly from concrete panels, or concrete frame with brick partition walls. Regulation forbids flamable materials in coridors, electrical wiring is burried inside plaster. So if there is a fire, usually starts in a flat, and there is a barier for a flame and smoke to spread to corridor. Some buildings have stairwell separated by extra doors to separate staircase from smoke. Also, most of the buildings have distance heating, by hot water pipes, so there is no risk of fire from heating. It seems to me, that buildings are quite safe, but I coul not found reliable statistics to compare with different countires.
Do you have some statistics about fires internationally ? Without firm numbers this discussion is pointless.
I linked it in the previous post. The US has the highest age-adjusted fire death rate in the developed world.
https://www.worldlifeexpectancy.com/cause-of-death/fires/by-country/
The majority of housing in the U.S. is low rise wooden construction which doesn’t tell you much about high rises. The majority of most things west of Ninth Ave. are low rise.
It suggests that the safest mid/high rise buildings are the safest ones that can be built cheaply, as to get as many people out of low rise wooden construction as possible. The benefit of additional fire safety features, effective or not, has to be weighed against cost increases encouraging people to live in the death traps that make up the vast majority of the current housing stock.
the floorplate efficiency is notably higher, 92.5% in the first case and 94% in the second case, compared with 89.5% in the first case of the double-loaded corridor and 86.67% in the second.
Your efficiency numbers are way off if you are taking them from your representative gray drawings. Your stairs at either end of the hallways are too large, the footprint for a North American egress stair should be smaller than the footprint of a Euro point access stair because the egress stair only needs a single door in and out and not the (even minimal) circulation to access the four units with their four doors. Similarly, if your central block in the first example is representing a scissors stair it should be less than double the size of a end stairwell. If you are assuming elevators they should be centrally located on both, developers never put elevators at the end of a hallway (hotels sometimes do) to minimize undesirable units with a long walk from the elevator. But if you are including elevators your cores for the point access buildings are too small in comparison.
Note I am not disputing that point access housing is more floorplate efficient because there is clearly more space lost to a full length hallway, but I cannot accept your values without looking at a more accurate floorplan.
A third housing typology puts all apartments on a corridor . . .The corridor is then in the open air . . . This is not unheard of, but still rare.
This typology is quite common in the sunbelt of the US, the garden apartment style that is particularly prevalent in LA. With open air corridors it is probably as cheap or cheaper as a double loaded corridor. If the corridor is inside it is definitely more expensive because you have all the cost of building the indoor square footage of the corridor with half of the units to carry the cost.
The stairs at the end of the hallway are taken from a real Seattle development that Mike Eliason complained about for being too deep on Bluesky a week ago; the dimensions are around 6*8, with an elevator near each staircase rather than in the middle. You can go smaller if these are staircases without an elevator, but then there needs to be a middle bulge for an elevator lobby.
Low-end California hotels and other buildings have single-loaded corridors, yeah. As I said, it’s a typology that isn’t unheard of, just not common in North America and Europe.
I would like to see the plans for that Seattle building. 6m x 8m is big for a stair and elevator; egress stair footprints can be 2m x 5m, even an ADA elevator shaft can be done in 2m x 3m, and the elevator can/should open directly to the hallway.
There is of course variability in all of this based on size of building (more height/tenets leads to more shafts or wider stairs to handle the load). Still, your euro models certainly do not have an elevator to each unit so using your Seattle example is not comparing fruit to fruit. Plus a building with elevators at each end of the hall is unusual.
I do not dispute that point access stairs will lead to a better floor area efficiency, but if your prototype for end stairs is, say, a 7 story Seattle building with four elevators and an atypical layout but your Euro prototype is a four story walkup with no elevators then I would say you are biasing the sample.
And to be clear, my European prototypes all have elevators; 2.5*7 is enough for a staircase and an elevator here.
In turn, light wood is less safe in fires – but those codes don’t exempt concrete buildings from the two staircase requirement.
Wood framed buildings are not less safe in a fire. As I noted in the last thread fire safety is almost entirely a factor of if the building has sprinklers or not. Secondarily is the firestopping and fireproofing – a modern wood building with properly rated walls and shafts will do better than an old concrete building with routes for fire/smoke to spread floor to floor. Grenfell Tower was a concrete building and we know how that turned out. The fact that Grenfell was structurally sound after the fire ended didn’t save anyone who burned inside it. Conversely, two years before, a massive fire at a wood apartment building in Edgewater NJ destroyed 240 of the buildings 400 units but no one died – the Edgewater building was fully sprinklered.
I didn’t know apartment block configurations could be a class war topic. And everything seemingly revolves entirely around anti-social behaviour.
I will not pretend to understand American politics. I will only comment from a Sino-European standpoint.
In parts of China (around Shanghai where I’m from) they almost exclusively build point-access blocks of the second variety – dual aspect 2 per floor ~15 metres deep – even for buildings more than 30 storeys high. Nothing else sells. Dual aspect is non-negotiable and kitchens/bathrooms without windows are frowned upon. (Almost nobody has open plan kitchens because of Chinese cooking – pristine sofas and piano in the same room as a wok doesn’t bare thinking about) There’s very rigid societal expectation of which directions rooms should face – living room and master bedrooms should face south, study and everything else should face north. The result is a slightly boring streetscape as everything is a thin slab orientated the same way placed equi-distant apart, but at street level things work OK.
Dual-aspect point-access blocks are common in Europe, I think largely due to an expectation that flats need to cater for families. In Britain (particularly England) where where’s a stronger ‘house’ culture ‘hotel-corridor’ thicker blocks are the most common among new builds. Up to the 90s council blocks would often have external corridors. Thicker blocks are easier on the eye at street level – more interesting corners and avoiding streets flanked by thin sides – the aesthetics driven urban advocates seem to like that. Thinner blocks need more height to get the same plot density, so Britain’s cultural aversion to height also lead to thicker, squatter blocks of single-aspect flats.
If the US apartment market can only realistically cater for childless youngsters (it’s too easy to buy a massive house with a driveway) and topics like shared facilities cannot get away from anti-social behaviour, then, well, the US is going to US.
Post Trump I was looking at the house price data and US house prices are higher than ours on average now, albeit that of course you get more space.
$420k median now, vs £267k in Britain.
OK looks like the nationwide one is a little low compared to the Geometric mean from the government – https://www.ons.gov.uk/economy/inflationandpriceindices/bulletins/privaterentandhousepricesuk/january2025. So it’s similar now. But still.
In the US, the thicker blocks come out of aversion to height, yeah, in two ways:
1. Zoning laws aiming at creating a nice streetscape rather than just regulating density, e.g. the quality housing program in New York, aim to reduce height rather than floor area ratio. This also includes some psychologically dodgy rules about breaking up the massing of a building so that it doesn’t have a contiguous street wall.
2. Construction techniques, in which light wood is an acceptable building material, and there’s not much experience with concrete (outside New York and Florida), which imposes a sharp seven-story limit, to the point that outside some unusual circumstances, buildings have 5-7 floors or 15+, nothing in between – the marginal cost of the eighth floor is so high that it’s only justifiable if it’s possible to amortize the land over many more floors.
Thin sides are not at all bad for the urban streetscape. Euroblocks with 14 meters of depth and no wings end up having more interior courtyard space.
Antisocial behavior isn’t really an issue at any of these American buildings. They’re access-controlled, and residents don’t find the common areas unsafe. The elevators, for example, are clean, and there’s no stereotype that they aren’t the way there is at public spaces like subway elevators.
They import concrete workers for all the commercial buildings that are concrete?
The construction costs are just much higher for those concrete buildings, and honestly also for the five-over-ones (whereas for single-family housing American construction costs are as low as here or even lower).
and there’s not much experience with concrete (outside New York and Florida),
This is absurd, where are you getting this nonsense, there are concrete buildings built all over the US in cities everywhere, all of the time. To say nothing of the concrete podiums in 4+1 or 5+1 buildings which use the exact same same techniques as building a multi-story concrete building.
which imposes a sharp seven-story limit,
The limit for wood stick framed construction in most US jurisdictions is 60 ft and/or 4 or 5 stories, which translates to 5 or 6 stories with a podium. The 2015 Intl Building Code restricted timber frame buildings to 85 ft or 6 stories (although 85 ft could be 7 stories) but in 2021 with the developments in mass timber and engineered lumber in 2021 that was raised to 18 stories. There is of course lots of variation in local codes, Portland approved an 11 story mass timber building (legally a high rise) in 2017 for instance.
to the point that outside some unusual circumstances, buildings have 5-7 floors or 15+, nothing in between
All of the discussion of construction techniques and building code is generally irrelevant to building height though, since the controlling factor for height is virtually always zoning codes, not building techniques. Except for famously Houston, the US is notorious for zoning codes that place strict height restrictions because of adversity to non-single family neighborhoods or the concept of height in general. Developers will build as high as possible if the market allows. The 5-7 and 15+ typology is because US politicians won’t zone their urban parts of their city for more than an “acceptable” 5-7 stories to avoid “Manhattanization”, except for the very downtown core (or cores) where they go all out for not just high rises but skyscrapers. The ‘West Coast Compromise’ (SF-Seattle-Vancouver) you refer to below where high rises right at a transit stop or along an arterial are allowed as long as everything else is downzoned to low-rise/single family (no mid-rise) is a symptom of this, and produces worse results than if the entire area were zoned for mid-rise.
On top of that there is also probably a natural reason for building heights in this range. The very nature of cities, aggregation and travel geometry means that there are a few areas where demand is really high (CBD, downtown, secondary center/travel node) and it makes economic sense to build as high as possible. In most other areas demand isn’t so sharp, and it doesn’t make sense to build much higher than 5-7 stories regardless, either units in a higher building will go unsold/unleased because people will be living in another building somewhere else, or the extra construction costs (more elevators, stronger structure) will make the building unprofitable even if it is fully occupied at what the market can bear.
The view west of Tenth Ave. is very very dim and fuzzy.
The same construction workers who slap up wood framing on Monday slap up steel framing – for commercial – on Tuesday – and where code requires fire resistant multi family they do just that.
The view east of Queens Plaza gets dim too. There are lots of places right at the subway stop with single story retail surrounded by two family and single family houses. Or Great Neck Plaza. It’s okay if things are different in different places.
Others have said that you do 3 floors or 10 because 4 floors you start to need an elevator and those are so expensive that you need to serve 10+ just to spread the costs out over enough units. You can of course put an elevator in anything but rents becomes enough more expensive that many would not agree to it.
That is another thing that I’m not able to evaluate the truth of. However it needs to be considered – elevators in the US are expensive.
This points to an issue with the various calculations and claims in this piece. In the Euroblock model the “interior courtyard space” is not counted. In the vast majority of instances a block consists of duplication of the single-loaded plan ie. each on the two (long) streets defining the block, internally separated by those courtyards; and the courtyards have to be a certain size because all have apartment windows facing onto them (they are not just airshafts for bathrooms/kitchens). The Americans have simply replaced the substantial courtyard with the minimal single internal corridor servicing both blocks. Thus, strictly one should include the Euroblock courtyard in calculations, ie. it should be based on the developed land area of the whole block. Econocratically the double-loaded system is more “efficient” but let’s be clear, also far worse aesthetically for the residents. And worse for family apartments because Americans are not allowed to build windowless bedrooms deep in the apartments, ie. those adjoining the internal corridor.
Note that the “snowflake” towers in Asia also need to count all that space separating the sub-towers. Thus they are also less econocratically “efficient” as the American design but, as pointed out by others, it is the absolute preference by Asians (who are right). In fact in some parts of the Anglosphere there is a distinct trend towards a version of the snowflake layout, if not as extreme, and for exactly the same reasons (plus a lot of Asian buyers?). The monstrous monolithic square hi-rise may be most “efficient” for the property developers and builders but crap for residents. For the wrong reasons the skinny supertall hi-rises in NYC are really the same thing ie. with format similar to one wing of a snowflake tower.
I don’t think there is any real doubt about the negative effect of very long unchanging street walls. But there are various ways of coping with it and Haussmannian design clearly overcomes the problem. Karl Marxhof is another example in different context (only partly successful IMO) but the opposite is the oppressive Faluház. While in the Anglosphere, and perhaps ultimately everywhere because brute econocrats dominate this world, regulators have to counter property developers innate disdain for spending any money on anything that doesn’t benefit themselves, let alone the city or residents.
Right. Much the same reasons for Haussmannian and pre-Haussmann (ie. in 17th century Paris when it all began) height limits. Combined with calculations on light and air. And fire safety; 5-7 floors are at the limit of even modern fire-fighting systems (extendible ladders, fire hoses) which is so dramatically demonstrated in those hi-rise fires caused by cladding.) Regardless of the awful quality and short lifespans of the American 5+1 stick-build, it is good for urbanism. (To those who claim timber buildings can’t last, I remind them of the 350-year old housing on Ile St Louis, Paris, that I happened to live in. As Alon has pointed out, either “massif” timber, ie. solid, or modern engineered glulam etc can last for very long times and be no more of a fire risk, perhaps less risky, than all-masonry construction. (There have been some critiques of such 19th-20th century buildings but it is self-serving b.s.) As I forever point out, when this model incontestably achieves the highest residential densities in the world, why argue for anything else? Only if you are a property developer.
Note that Alon’s proposal in the KWCIMBY piece has very large internal courtyards, fancifully coded green in the plans but almost certainly grey in reality (nothing is going to grow in them when surrounded by 30-storey buildings; close to Joburg’s Ponte City). Clearly such large courtyards don’t work. They are pointless and counterproductive in hi-rise, and either unnecessary in low-rise (Haussmannian) or won’t persist (the lost courtyards of Cerda’s Eixample). The Spanish Mission style with leafy courtyards and fountains may be much loved but, alas, not likely to return.
Euroblocks as practiced here are not at all monotonous, is the point. The street wall is contiguous, without anything breaking up the massing, and it’s completely fine. It helps that the point access block scales down better, and is cost-effective with a building width in the 10-25 meter range, so that each section of (say) 20 meters of street wall looks a bit different. But the styles are often the same – not every street is eclectic here or in Paris, and it’s fine.
The double-loaded corridor is not efficient, is the point. It exists because of peculiarly North American regulations that evolved without dialogue with the rest of the world, leading to a larger amount of wasted space. I wouldn’t compare any of this with the euroblock courtyard, which does not need to be built, fire-rated, or heated. The courtyard takes up space, but that’s fine – construction methods here can build taller, which is why Parisian buildings routinely have nine floors, a number that more or less does not exist in modern North American construction because it’s in the valley of cost-effectiveness between 6-7 and 15+.
A separate issue from this is also the structure of density. North American TOD has too steep of a dropoff, in what is called corridor zoning: tall on the arterials, single-family or missing middle (which isn’t really missing) away from them even a single block away. Note that this isn’t exactly about maximizing density near the train stations, because a lot on an arterial street 300 meters from the subway stop will be part of this upzoning too, whereas one on a side street 200 meters from it will not. In effect, apartments are put only at the noisiest, highest-car traffic locations. In contrast, here TOD zoning extends in all directions, without the Canadian and Pacific Northwestern US juxtaposition of thick mid-rises and even high-rises right next to single-family zoning.
Finally, to the point about the courtyards: the courtyard at my building is rather wide relative to building height, but 10 meter wide courtyards flanked by six- and seven-story buildings are pretty common in Berlin, for a 2:1 ratio.
Actually that was my point. However there are some, probably from the 50s thru to 80s that come close. And that is why I understand building regs that talk about limiting long stretches of sameness. Haussmannian and other Euro buildings prewar had grand entrances, window and balcony detailing etc that stopped this descent into monotony that the International Style in particular was prone to.
My point was that it was the most “efficient” for the property developer because it gave the most sellable area for the land (block). Clearly internal courtyards of Euroblocks reduce that while of course making them better (more “efficient”) for residency. It is precisely why the double-loaded form is so dominant in the Anglosphere.
You’ve written such things before and I still wonder if I misunderstand. But it is very clear. Older Parisian residential buildings are almost all 6 to 7 with very few at 8 floors; this is at least 90% of the entire housing stock. More recent buildings can achieve up to ten floors within the same height regulations because they build much lower ceiling heights. But those are probably less than a few percent of all housing stock. That low ceilings are probably also considered “efficient” but I consider a terrible development because it makes smaller living spaces quite a lot worse than they need be.
I’d bet they aren’t being built quite so generously today except perhaps in very upmarket zones.
As to the discussion about TOD etc, my position is that allowing hi-rise residential is not the way to go. The extremes you point out (5+1 or 15+ with nothing in between) is awful for most purposes. It only exists due to property developers power over politicians, especially local city politicians. It doesn’t make for good urbanism and doesn’t support the best TOD. It doesn’t even support the best density which is supposed to be the point.
I also think to build on Michael’s point that people like living in smaller buildings.
I do also agree with Michael that within reason low ceilings are bad.
@Michael
Double loaded corridors are only more efficient if height is capped (artificially either by planning regulations or by weird unit cost thresholds).
I’ve not done the maths properly, but I’m sure I’m there and thereabouts: say an 100x100m plot can deliver a certain number of units with doubled loaded thick blocks of 5 storeys; you can deliver the same number of units at same sizes with dual-aspect 14m thick blocks of 7 or 8 storeys.
I must not be making myself clear, when I wrote:
For the Euroblock you must first subtract all the internal courtyards, generally at least 5m deep but in some cases like Alon’s up to 10m. Then they still have to have corridors and stairwells for access to the street. There is no way when calculating for the whole block (the land, not the building) that Euroblock uses more of the land area for habitable use than the Anglosphere double-loaded which has no courtyard at all and just the minimal (2.5m?) single corridor serving the entire block. “Habitable” is used in the French legal sense, ie. enclosed private space–it doesn’t even include balconies (when selling you can cite the balcony and its size but legally you must not include its area in your claim of habitable area). “Efficiency” here only relates to the amount of space given over to habitable use (or saleable or rentable), not to its quality. I think double-loaded is an awful design and will never live in such a building.
Incidentally your 100m x 100m is problematic. First, very few are of that size. Euroblocks might be 100m long but usually 50m or less deep; ie. defined by streets on all sides. You’d have trouble fitting in either double-loaded single building or a ‘normal’ Euroblock (ie. one set of central courtyards) in your example. So your example is too complicated to apply these definitions. Instead we should use something like the plan by Mike Eliason reproduced by Alon in a comment, which looks roughly what I said, 100×50. Or take a look on Google maps at the block defined by rue Chanoinessse/rue des Ursines (adjacent to Notre Dame) which is about 120m x 50m; in fact it is a bit too deep for a single set of courtyards but certainly demonstrates what I am talking about. (G maps of course do not show internal corridors and stairwells).
@Weifeng Jiang
You don’t even need the 8th story. A five story 20m deep double loaded building with units on every floor needs a 7.1 story 14m deep dual aspect building for the same number of units at the same size. If the ground floor is not residential (retail, parking, common areas) then the building needs to 6.7 stories tall for the same number of units.
I must admit I ran these calculations because at first I didn’t believe you and thought the dual aspect layout would less efficient than it is.
There’s a separate issue here in that recently-built European dual-aspect apartments tend to be smaller than recently-built North American single-aspect ones for the same number of bedrooms.
Part of the issue is wealth – those American apartments are built in a wealthier and more unequal society, with plenty of middle-class disposable income for a bathroom in every bedroom. But then again this is also seen in Canada, which is not especially wealthy or unequal by Western European standards.
The other part is floorplate efficiency of apartments with more window space, especially if those apartments are larger to begin with. For example, take three 12*9 m apartments, two on a double-loaded corridor (one in each orientation), one in a point access block or at the end of a single-loaded corridor. You need around 3 meters of width for a room – bedrooms can be a bit less, but living rooms generally can’t, so you’re not squeezing a living room and three bedrooms with 9 meters of frontage, or a living room and four bedrooms with 12. The upshot is that the 9 meter deep double-loaded corridor apartment is a three-bedroom, with an open plan kitchen, and a living room that’s awkwardly narrow; the 12 meter deep double-loaded corridor apartment, which is uncommon but does exist as in the example I linked in Mike’s skeet, will either be a two-bedroom or have windowless bedrooms, which is a compromise often seen in office-to-residential conversions. The dual-aspect apartment will enter to a living room and essentially be able to organize itself as six 3*6 spaces, minus some circulation and bathroom space, which will be in practice a four-bedroom as the living room takes two of the 3*6 spaces, with or without a separate kitchen.
Israeli families generally want to live in a place with a lot of windows and a nice view, and tall buildings are a way of getting that – topography can also be used for this in the places where it exists. As far as I can tell single people tend to care less about that.
America already has a typology like the single-stair point access block. It’s called here a suburban-style garden apartment complex, which tend to be three to four stories. A sample floor plan can be found here: https://images.squarespace-cdn.com/content/v1/53e7c118e4b0ff55cc9afe25/1431517157594-J9LOAHLO7UAMS4LKC5R0/mf-20-APT-pline.jpg?format=1000w. Unfortunately, new construction of this style tends to be in the low-regulation Sun Belt suburbs of Texas and Atlanta, in large complexes surrounded by acres of parking and grass (hence the “garden apartment” terminology). Can urban America successfully transplant this typology into new housing? Possibly, but I believe it depends on security and market factors. Urban America has more crime than Europe and Asia, possibly because of greater socioeconomic inequity and less ethnic homogeneity, and having more single-point vertical accesses costs more to provide security (multiple access points versus a single main entrance/lobby with a doorman or security guard). In lower-crime suburban neighborhoods, this can be ameliorated with single access into a large complex of these buildings, but for higher-crime urban neighborhoods, security costs can easily scale up to unaffordable levels if each single-stair point access requires its own security infrastructure due to small or constricted urban sites.
Another factor is the American general market preference (and often code requirement) for elevators in buildings more than three-to-four stories tall. Elevators are also generally necessary for access to any code-required ADA-accessible apartments planned for above the ground floor, and these elevators must be large enough to accommodate a wheelchair, including the wheelchair turning radius. The larger sized elevator further increases the cost of elevator service. To keep housing affordable, each ADA-compliant elevator must service as many apartments as possible, and the only way for an elevator to service many apartments is with a corridor building. Five-to-six story apartment buildings without elevators (single-stair point access block) are generally not feasible to develop in light of code requirements for percentages of ADA-accessible apartments while also keeping these accessible apartments to the ground floor. This does beg the question, is it possible to develop significant numbers of ADA-accessible, affordable, 4-bedroom, large family apartments without elevators in dense American-regulated urban environments?
The stacked townhouse typology (2-story unit above a second 2-story unit) was developed as a modification of the single-stair point access block which does not require elevators. Stacked townhouses without parking provided can be developed by small developers on small urban lots/sites as a denser affordable missing-middle typology, but generally result in larger units due to the duplex nature of the stacked units. Given a development that is small enough, ADA-accessible requirements might not be triggered, or might be possible to provide with a two-over-one-over-one stacked townhouse with an accessible unit on the ground floor. Developing new construction four-bedroom family-friendly stacked townhouses in an American urban environment without parking is economically feasible, and probably is the more regulatorily-effective way to develop new construction family-affordable missing-middle apartment housing to urban American environments compared to a four-story single point access block.
…. has two staircases.
British rules certainly either require or it is very much desired to have lifts for more than 3 stories, and they need to be big enough for a wheelchair (or to be fair a fairly large piece of furniture).
Lifts are also pretty expensive, the rule of thumb I heard a few years ago was £100k plus £100k a floor (so probably £150k plus £150k a floor now).
E.g. Dunelm won’t deliver above the 2nd floor without a lift – https://www.dunelm.com/info/help/delivery
Interesting discussion. Look at the LA fires. Gov Newsom suspended affordable housing requirements in these areas. Fossil fuel ban is suspended (you can reinstall gas ovens and gas dryers). Solar panel/battery requirements are suspended. Single family housing will return.