Daniel sent us this one. He was tracking a skyscraper going up here in Jerusalem, and he stumbled onto this website — the Council on Tall Buildings and Urban Habitat. And what he found was basically a whole academic and professional discipline he didn't know existed. A field dedicated to making high-rises work as neighborhoods, not just towers. His question is, who are these people? Who are the vertical urbanists, what do they actually believe, and what are they arguing about among themselves?
This is one of those moments where you find out there's a name for something you've been noticing your whole life. You walk past a tower, you feel something about how it meets the street — or doesn't — and you think, someone must study this. Turns out, yes. Thousands of someones.
The timing's right. The UN projects sixty percent of the world's population in cities by twenty thirty. Skylines are transforming from Dubai to Shenzhen to Nairobi. The question isn't whether we'll build tall — it's whether we'll build tall well. And that second question has an entire field behind it.
The CTBUH itself — founded in nineteen sixty-nine at Lehigh University, now based at the Illinois Institute of Technology in Chicago. They're the ones who officially decide what counts as a "tall building," they maintain the global database, they publish the research journal, they run the annual congress. If you've ever heard someone argue about whether a spire counts toward building height, the CTBUH is the referee who settled that debate.
Which is the kind of institutional authority that sounds absurd until you realize it shapes what gets built and where.
And Daniel's discovery — that there's a whole field here — that's the thing I want to sit with for a second. Because most people think skyscraper design is just architecture plus structural engineering. You hire an architect to make it look good, an engineer to make it stand up, and you're done. Vertical urbanism says no — you need sociology, environmental science, transit planning, public health. You're not designing an object. You're designing a vertical neighborhood where thousands of people will live, work, raise kids, grow old.
The field is the answer to the question Daniel asked once before — whether high-rise building is a specialty within architecture. The answer is yes, and it's bigger than architecture.
And the core premise — I think this is worth stating up front — is that density is the most sustainable urban form. Concentrate people, preserve green space, reduce car dependency, enable district-scale energy systems. That's the vertical urbanist thesis in one sentence. Everything else flows from there.
The counterintuitive part being that a fifty-story tower can be more environmentally responsible than a six-story mid-rise, if you do it right.
If you do it right. That's the whole field.
If you try to define the field in a sentence — which I will attempt, at risk of oversimplifying — vertical urbanism is the study of how to make tall buildings function as complete neighborhoods across the vertical axis. Not just stacking floors. Designing for how people meet each other on floor forty-two. How a child walks from their apartment to a playground without touching the ground. How waste, water, energy, and social life all move through a building that's effectively a small city stood on its end.
The difference from traditional skyscraper architecture is basically the difference between designing a sculpture and designing a street.
And it's why the CTBUH renamed its journal. It used to be the Journal of Tall Buildings. Now it's the Journal of Tall Buildings and Urban Habitat. That second half — urban habitat — is the whole point. Traditional skyscraper design cares about the silhouette on the skyline. Vertical urbanism cares about what happens in the lobby, on the sidewalk outside, at the transit connection, in the sky garden on the twenty-sixth floor. It asks whether residents know their neighbors, whether the ground-floor retail actually serves the people upstairs, whether the building makes the street better or just extracts value from it.
Which is a much less glamorous set of questions than "how tall can we make it.
Much less glamorous. And much harder to answer. The CTBUH has been pushing this shift for about two decades now. They run the annual best tall building awards, and if you look at the winners over the last ten years, they're almost never the tallest. They're the ones that solved a specific urban problem. A tower in Sydney that restored a mangrove ecosystem at its base. A mixed-use complex in Shenzhen that connected three previously separated neighborhoods with public walkways through the podium. The field is actively redefining what success looks like.
When Daniel asks who these people are — the vertical urbanists — part of the answer is, they're the ones who think the most important part of a skyscraper is the six feet where it meets the ground.
And if you trace that idea back to the people who built the intellectual framework, you keep running into the same name — Antony Wood. He's been the CEO of CTBUH since two thousand six, and he's basically the field's evangelist-in-chief. Professor at IIT, trained as an architect in the UK, spent years in Asia watching cities transform at a speed and scale that Europe and North America never experienced. And he came away with this conviction that the Western model of the skyscraper — glass box, single use, isolated from the street — was a dead end.
He's not just cataloging tall buildings. He's arguing for a specific kind of tall building.
Very much so. Wood's whole thing is that the skyscraper has to become a "vertical city" — his phrase — rather than a vertical gated community. He points to Hong Kong as the proof of concept. Six and a half million people on seven percent of the territory's land. Urban densities of six thousand five hundred people per square kilometer, compared to maybe four hundred in a typical US suburb. And it works because the towers aren't just residential silos. They're connected to transit, to street life, to markets and schools and parks. The density forces integration.
Hong Kong as the accidental laboratory.
Nobody sat down and said "let's design the world's most vertically integrated city." It was geography — mountains on one side, harbor on the other, nowhere to sprawl. But the result is what vertical urbanists point to when they say density isn't the problem. Bad density is the problem.
Wood's argument is that you can design for good density intentionally, rather than just hoping geography forces it.
That's the whole project. And the second figure I'd put in the pantheon is Jeanne Gang. She runs Studio Gang, based in Chicago. Her most famous building is probably Aqua Tower — eighty-two stories, and the balconies undulate. They're not decorative. Each balcony extends a different amount, and the pattern is engineered to break up wind loads so the building doesn't need a massive tuned mass damper. But she also designed them to give every resident outdoor space at height. You can step outside on the sixty-third floor and feel wind and see the city, not just press your face against glass.
She's solving an engineering problem and a livability problem with the same design move.
That's her signature. She calls it "actionable idealism." Her firm did a tower in San Francisco — MIRA — where the facade twists so every unit gets bay views without blocking the neighbor's. And she's been pushing for what she calls "social condenser" designs. Buildings where shared spaces aren't afterthoughts tucked next to the elevator bank. They're central to how you move through the building.
That phrase — social condenser — that's not hers originally, right? That's Soviet constructivist stuff from the nineteen twenties.
And she's explicitly reviving it for the high-rise era. The original idea was that architecture could engineer community — design buildings where people couldn't avoid encountering each other. Gang's version is sky gardens, shared kitchens, laundry rooms with views, staircases people actually want to use instead of emergency exits that smell like concrete.
Which brings us to the third name. William Pedersen at Kohn Pedersen Fox. And he's been at this even longer.
Pedersen's been designing supertalls in Asia since the nineteen nineties, when the whole idea of mixed-use vertical cities was still speculative. KPF did the Shanghai World Financial Center, the International Commerce Centre in Hong Kong, the Lotte World Tower in Seoul. But Pedersen's contribution to the theory is that he kept insisting these weren't office towers with some retail at the bottom. They were vertical mixed-use districts. Office, hotel, residential, retail, public observation decks — all in one structure, with different populations using it at different times of day.
The building never goes dead. It's not a nine-to-five tower that empties out at six PM.
That's the argument. And Pedersen was making it before anyone had data on whether it actually worked. Now we have CTBUH research — their twenty twenty-three Vertical Cities report tracked turnover rates. Buildings with dedicated community floors, sky gardens, and mixed-income units had forty percent lower resident turnover than purely residential towers. People stay longer when they feel like they live in a place, not a unit.
Forty percent is not a marginal difference. That's a structural signal.
It's enormous. And it gets at what I think is the most interesting design challenge in the whole field. How do you create social infrastructure at height? Not just stacking units and hoping people bump into each other in the lobby. Singapore's Pinnacle at Duxton is the case study everyone cites. Fifty stories, seven towers connected by sky bridges, sky gardens every eleven floors. Public housing — not luxury. And the sky gardens are designed as actual places. Benches, plantings, views, space to sit and talk. Residents report knowing their neighbors at rates that suburban developments would envy.
The mechanism isn't mysterious. You put a garden in the sky, people use it. You don't, they stay in their units. The question is whether developers will pay for gardens in the sky.
That's where the next part of this conversation gets uncomfortable. Because the advocacy is compelling, the case studies are real, the research exists. But the economics don't always cooperate. And the social questions — about who gets to live at height, and whether these communities actually mix or just stack — those are far from settled.
You mentioned economics not cooperating. Let's put a number on that. High-rises cost twenty to forty percent more per square meter to build than mid-rises — your six to ten story range. And that's not developer greed. That's structural systems, elevator cores eating floor plate, fire safety requirements that multiply past a certain height, construction timelines that stretch out.
The elevator math alone is punishing. Once you go past about thirty stories, you need a second sky lobby, express elevators, double-decker cabs in the supertalls. Every extra elevator shaft is rentable square footage you lose on every single floor.
The critique writes itself. If it costs forty percent more to build, you have to charge forty percent more to make the pro forma work. Vertical urbanism becomes a luxury product by default. The density argument looks great in a journal article, but on the ground you're not housing the middle class. You're building penthouses with a conscience.
The vertical urbanists know this is their weakest flank. The counter-argument — and I think it's partly right, partly aspirational — is that lifecycle costs flip the equation. District cooling from a central plant is more efficient than a thousand individual air conditioners in sprawl. Land acquisition is a one-time cost that doesn't scale with height. Transit infrastructure serves more people per stop. The problem is those savings accrue to the city over decades, while the construction premium hits the developer on day one.
You need a developer with either a very long time horizon or a government willing to subsidize the gap. Which is why the best examples are in Singapore, where the state builds the housing, or in markets where land is so expensive that the construction premium disappears into the land cost.
It's not a universal solution. It's a solution for specific economic conditions, and pretending otherwise is where the field loses credibility.
The second debate is stickier. Richard Sennett, the sociologist, has been making this argument for years — that high-rises create vertical segregation. Rich at the top with the views and the quiet. Poor at the bottom with the street noise and the delivery truck rumble at six AM. You're not mixing. You're stacking.
The design response is interesting because it basically concedes the diagnosis and tries to engineer around it. Shared amenity floors — put the pool and the gym on floor thirty, not the penthouse. Mixed-use podiums where the first ten floors are retail and offices, so the residential population isn't stratified by floor. The "vertical street" idea — elevator lobbies designed as actual rooms with seating and daylight, not fluorescent-lit corridors where you speed-walk to your door.
Whether any of that overcomes the fundamental fact that the penthouse costs more than the fifth floor — I'm skeptical. You can design all the shared spaces you want. The market is still sorting people by price, and price correlates with height.
That's the honest answer. The design can reduce isolation — the forty percent lower turnover we mentioned earlier suggests it does something real. But it can't eliminate the economic sorting unless the building itself is non-market housing.
Which brings us home. The Gateway project. Daniel's been watching this one because it's in Jerusalem, it's enormous — twenty towers, two thousand five hundred units, half a million square meters of mixed-use space — and it's bitterly contested. The opponents have shadow studies showing adjacent neighborhoods lose four hours of sunlight a day.
The preservation argument is emotionally powerful here in a way it might not be in, say, Dubai. Jerusalem's identity is tied to its low-rise stone character. You put a cluster of glass towers at the city's entrance and critics say you're erasing that identity before anyone even arrives.
The vertical urbanist response is that Jerusalem's population is growing, the housing crisis is real, and the alternative to building up is building out. And building out here has geopolitical dimensions that don't exist in Vancouver.
Sprawl into the West Bank versus density at the city's core — that's the actual tradeoff, and it's not abstract. It's the kind of tension where urban planning and national politics collide. The Vancouver model — slender towers on podiums with preserved view corridors — gets cited as a compromise, but Vancouver doesn't have Jerusalem's symbolic landscape. You can't just import Vancouverism and expect it to work.
Then there's the climate dimension, which nobody was talking about seriously ten years ago. Tall buildings create wind tunnels at street level. All-glass facades amplify urban heat islands. Evacuating a fifty-story tower during a wildfire or a flood is a problem we don't have good answers for yet.
The CTBUH launched something called Resilient Skylines in twenty twenty-five. Biomimetic facades that self-shade like termite mounds. Sky bridges that double as horizontal evacuation routes between towers. On-site renewables integrated into the structure rather than bolted on. It's ambitious. It's also mostly unbuilt.
The field knows the problems. It's naming them, it's researching them, it's publishing frameworks. Whether the solutions actually scale — that's the open wound running through every conference panel.
If you're a listener trying to make sense of a high-rise project in your own city — whether you're for it or against it — there are three questions worth asking that cut through most of the noise. First, is there an actual vertical urbanist on the design team? Not just an architect who's done tall buildings before, but someone who's published in this space, who's presented at CTBUH, who thinks in terms of vertical neighborhoods rather than iconic forms.
That's a concrete thing you can look up. Most firms list their team publicly on project filings. If you see someone whose bio mentions the Council on Tall Buildings and Urban Habitat, that's a signal.
Does the proposal include community infrastructure above the ground floor? Sky gardens, shared amenity floors, vertical circulation designed as social space rather than just fire stairs and elevator banks. If the renderings show nothing but residential units from floor two to the roof, that's not vertical urbanism. That's a stack.
The third one — what's the plan for lifecycle carbon, not just construction cost? Embodied carbon in the concrete and steel is one number. Operational carbon over fifty years is another. If the developer can't answer both, they haven't done the homework.
The field itself is young but scaling fast. CTBUH crossed ten thousand members across more than a hundred countries. Their World Congress next year in Singapore is themed "Vertical Urbanism for All" — that phrasing matters. It's a deliberate pivot from luxury to equity, at least rhetorically. Whether the projects follow the rhetoric is the question.
For anyone who wants to go deeper than a podcast episode, the CTBUH runs a free online database — the Skyscraper Center. You can pull up your city, look at every tall building, and compare them on density metrics, mixed-use ratios, green certifications. It's the same tool researchers use, and it's publicly available.
It's genuinely useful. You start to see patterns — which cities are building mixed-use versus single-use, which developers consistently include community space, where the certified projects cluster. It turns a vague feeling about a skyline into something you can actually evaluate.
Which is the kind of thing Daniel will disappear into for three hours and emerge with opinions.
I was about to say, this has Daniel written all over it.
Where does this leave the mid-sized city? Jerusalem, Austin, Auckland — places that aren't Hong Kong or Singapore. Can vertical urbanism scale to a city of eight hundred thousand people, or is it a boutique field for extreme land constraints?
That's the open question, and I don't think the field has answered it yet. The economics we talked about — the forty percent premium — that hits harder in a mid-sized market where land isn't priced at Manhattan levels. You can't just shrink the model and expect it to pencil out.
Yet mid-sized cities are where most of the growth is happening. The megacities get the attention, but the pressure is in places like Austin, where the population's doubled in twenty years and the sprawl is eating the Hill Country. The vertical urbanist argument should apply there. But the developers doing mid-rise infill are a different species from the ones building supertalls in Dubai.
There's a version of this that works at twenty stories instead of fifty. The principles — mixed-use, community floors, transit integration — don't require a supertall. But the field's intellectual energy is still concentrated at the extreme end.
Which is where the technology might change the math. AI-driven generative design for wind optimization is already cutting structural costs on some projects. Modular construction — factory-built units stacked on site — is bringing timelines down by twenty to thirty percent in places like Singapore and London. If the cost premium shrinks from forty percent to fifteen, the economics start working in a lot more cities.
The social questions don't shrink with the cost curve. Whether a building creates community or isolation — that's not an engineering problem. It's a design philosophy problem. And the philosophy has to come first.
Which brings us back to Daniel's original question. Is high-rise building a specialty? The answer is yes, and it has a name. It's got a research institution, a journal, ten thousand members, a global congress. It's a real field with real debates and real stakes. Whether it's the right answer for your city — that's still being written.
Now: Hilbert's daily fun fact.
Hilbert: In the early medieval period, Nenets shamans on the Yamal Peninsula used a single-stringed instrument called the sangkultap, carved from driftwood, which produced overtones that could be heard distinctly at two hundred meters across the frozen tundra.
Two hundred meters of frozen tundra overtone projection. That's a very specific acoustic property.
I have no follow-up questions.
This has been My Weird Prompts. Thanks to our producer Hilbert Flumingtop. If you enjoyed this, do us a favor and leave a review wherever you listen — it helps more people find the show. We'll be back soon.
