Tokyo is the largest city in the developed world. It is also the only one where housing is, by any reasonable measure, affordable. A young professional moving to central Tokyo in 2026 can rent a one-bedroom apartment, within twenty minutes of their office by train, for roughly a quarter of their take-home pay. The same person moving to central London will pay closer to half. Moving to central San Francisco, two-thirds. Moving to central Sydney, more than that.
The standard explanation — that Tokyo is somehow geographically blessed, or culturally distinct, or willing to live in shoeboxes — does not survive contact with the data. Tokyo is no denser than Paris. The average new apartment is no smaller than a comparable London flat. The land is no more abundant; the metro region is hemmed in by mountains on three sides and the Pacific on the fourth. What Tokyo has that London does not is a planning system that actually permits housing to be built.
The mechanism
Japan zones at the national level. There are twelve land-use categories, defined by national statute, and they apply identically in every municipality. A residential plot in central Tokyo and a residential plot in rural Kyushu are governed by the same code. If you own the land and your proposal complies with the code, you can build. The municipality cannot refuse.
"The planning system in Tokyo is not designed to optimize neighborhoods. It is designed to optimize building."
In London, by contrast, every borough writes its own plan. Every proposal is discretionary. Every neighbor has standing to object. A typical mid-rise residential development in Camden will go through eighteen months of consultation, two rounds of revision, and a public inquiry before it gets permission to be built — and that is assuming it is approved at all. Most are not.
What "as of right" means
The Japanese term is kenchiku jiyū, sometimes translated as "building freedom." It means that meeting the code is sufficient. The code itself is strict: it specifies floor-area ratios, height limits, setbacks, fire-safety standards, and minimum distances from neighboring buildings. But once you have met those specifications, no further approval is required. The architect submits the drawings, the engineer certifies compliance, and construction begins.
This sounds technical, but it has profound consequences. The single biggest source of cost and delay in modern housebuilding, in every country that has measured it, is not labor or materials. It is regulatory uncertainty — the risk that a project will be denied, delayed, or required to change after the design is finished. In Tokyo, that uncertainty is approximately zero. In London, it is the dominant factor.
What gets built
The visible result is that Tokyo continuously rebuilds itself in a way no other major city does. The average residential building in central Tokyo is about thirty years old. In London, it is roughly seventy. Older buildings are not necessarily better, and newer ones are not necessarily worse, but what matters for affordability is the rate of replacement. A city that adds 80,000 new homes a year, on a constant base of 7 million households, replaces roughly one percent of its stock annually. A city that adds 22,000 a year on a base of 3.7 million households replaces about half that.
The difference compounds. Over a generation, Tokyo absorbs three times the population growth London does while raising rents at a fraction of the pace.
The political economy
This is the part of the comparison that is most often misunderstood. Tokyo's permissive system is not the result of weak politics or absent NIMBYism. Japanese residents complain about new developments. Local councils receive thousands of objections every year. The difference is that, under the national zoning system, the councils have no power to act on them. The right to build is established at a level of government too high for any single neighborhood to capture.
London's system, by contrast, gives the maximum possible power to the smallest possible constituency. Every street has effective veto power over its own block. The result, predictably, is that nothing gets built. The people who would benefit from new housing — younger workers, immigrants, the future occupants of buildings that do not yet exist — have no representation in the process. The people who object are present, organized, and politically engaged.
This is not a uniquely British problem. The same pattern, with local variations, governs San Francisco, Sydney, Toronto, Auckland, Boston, and most of coastal California. In each case, planning power has been pushed down to the level of the affected neighborhood, with predictable consequences for supply.
The honest tradeoff
Tokyo's system is not without costs. Its neighborhoods change faster than London's. Buildings of historic interest are sometimes torn down. The visual character of a street can shift in a decade in ways that would take a century in Europe. People who value continuity find this disorienting, and they are not wrong to.
But this is, finally, a tradeoff — not a mistake. A city that prioritizes the comfort of its current residents above all else will eventually have only current residents. A city that prioritizes the ability of new residents to find homes will keep growing, keep refreshing, and keep being a place that young people can afford to move to.
The question every aging city now has to answer is which of these two cities it wants to be.