The Seduction of Form

Cities have always had a love affair with appearances. From the grand boulevards of Haussmann’s Paris to the neoclassical dreamscapes of the City Beautiful movement in Chicago, planners have often believed that beauty leads to order, and that order leads to better lives.

Form-based codes are a modern expression of this old desire. Instead of regulating what goes inside buildings—whether they’re homes, shops, or factories—they regulate how buildings should look and how they should line up along the street. Born in the late twentieth century as part of the New Urbanism movement, they promised to bring back walkable neighbourhoods, charming street scapes, and architectural harmony.

But promises are easy in theory. In practice, form-based codes have often proven clumsy, restrictive, or even counterproductive. They may make a place look pretty on paper, but they rarely capture the messy, adaptive, and unpredictable ways real cities actually work.

Beauty as Policy: The Ideological Roots of FBCs

To understand form-based codes, you need to understand the intellectual world of New Urbanism. In the 1980s and 1990s, a group of American architects and planners declared war on sprawl. They railed against strip malls, cul-de-sacs, and seas of asphalt car parks, longing instead for tree-lined streets, corner stores, and tightly-knit neighbourhoods.

Their model was the urban transect: a scale running from countryside to city centre, with appropriate forms of building at each level. To enforce this vision, they designed codes that specified where buildings should sit on a lot, how tall they should be, how close they should hug the street, and how the public and private realms should meet. The goal was not simply functional—this was an aesthetic and moral project.

Like the City Beautiful movement a century earlier, New Urbanists believed that the visual order of cities shaped the moral order of society. In their view, if buildings aligned properly, if porches faced the street and stores sat at the corner, then community spirit and civic pride would follow. It was a beautiful idea—but also a deeply ideological one.

When Good Form Turns Bad: Three Global Lessons

The trouble begins when the dream of order collides with the reality of cities. Around the world, form-based codes have stumbled in very different ways.

Miami, USA – When Miami adopted Miami 21 in 2010, it became the poster child of form-based codes. For the first time, a whole city would be shaped by design rules rather than land-use categories. But within a few years, cracks appeared. The code was so rigid that developers had to seek exceptions just to build affordable housing. What was meant to bring clarity instead brought gridlock.

Poundbury, England – Prince / King Charles’s model town, built under New Urbanist principles, is visually impeccable. Its streets look as if they’ve stepped out of a period drama. But it is also expensive, homogeneous, and socially narrow. Poundbury is less a bustling town and more a curated lifestyle product—proof that a pretty facade does not guarantee diversity or vitality.

Chennai, India – In one of the world’s most dynamic and informal megacities, attempts to impose form-based rules on dense neighbourhoods quickly ran into trouble. In areas where families build and extend their homes one room at a time, the code’s demand for fixed frontages and uniform street lines was not just irrelevant, it was hostile. Rather than helping people improve their neighbourhoods, the codes threatened to criminalize the very practices that made housing affordable.

Three very different cities, three very different outcomes, but the lesson is the same: form-based codes often fail to account for the fluid, improvised, and contradictory nature of urban life.

The Deeper Problem: Mistaking Looks for Life

The flaws in these examples aren’t accidents—they reveal a deeper weakness. Form-based codes rest on the belief that if a city looks right, it will work right. But cities are not paintings. They are living systems, full of conflicting interests, shifting economies, and constant surprises.

By prioritizing appearances, FBCs risk producing places that are orderly but brittle. They work well in planned developments or historic districts, but they stumble in cities that are diverse, fast-changing, or struggling with poverty. In these contexts, beauty becomes a cage.

And beneath the surface, there is a politics of exclusion. By embedding taste into regulation, form-based codes often become tools for preserving privilege—blocking density, discouraging unconventional housing types, or enforcing stylistic conformity. The codes are marketed as neutral, but in practice, they can act as a velvet glove for NIMBYism.

Thinking Beyond the Code: More Flexible Alternatives

So what might work better? Not a return to the old, rigid world of Euclidean zoning, but something more fluid, adaptive, and open-ended.

Blended Rules: Instead of choosing between regulating use or regulating form, combine both—lightly. Allow broad mixes of uses, set generous ranges for building form, and add performance standards for energy, affordability, and accessibility.

Time as a Regulator: No code should last forever. Regulations should expire, adapt, or shift as conditions change. A district might allow temporary workshops today, but morph into a housing zone once transit arrives. Sunset clauses would force periodic review instead of locking cities into outdated moulds.

Planning by Negotiation: Rather than prescribing one “correct” look, give communities a say in shaping their morphologies. With the help of visualization tools, residents could see different scenarios and agree on a menu of options. The result: places that feel legitimate because they are co-produced, not imposed.

The Right to the Messy City: Cities thrive on difference and contradiction. A warehouse next to a studio, a shop under a flat, a workshop beside a café—these juxtapositions are what make cities hum. Regulations should stop nuisances like noise or pollution, but they should not stamp out the everyday mess that produces vitality.

The Algorithmic Turn: What AI Could Offer

The irony is that the rigidity of codes may soon be challenged not by human reform but by machines. Artificial intelligence is beginning to offer tools that could make planning more dynamic, adaptive, and transparent.

Imagine a regulatory system that could simulate hundreds of futures for a neighbourhood—testing which combinations of housing, shops, and public spaces produce the best results for affordability, sustainability, and livability. Or imagine “regulatory dashboards” that adjust permissible forms in real time as demand for housing changes or as climate risks intensify.

AI could also make public participation less abstract. Instead of deciphering planning jargon, residents could see visual scenarios of how their street might evolve under different rules, helping them make informed choices. And machine learning could spot unintended consequences early: detecting when regulations are pushing up prices, excluding certain groups, or encouraging climate risks.

Such tools hint at a radical possibility: planning not as a static rulebook, but as a learning system—a framework that adapts and evolves as cities do.

From Frozen Pictures to Living Systems

Form-based codes were born out of good intentions: a reaction against sprawl, a longing for walkable neighbourhoods, a desire for beauty. But their reliance on form as destiny betrays a flaw. Cities are not static pictures. They are living systems, constantly in motion.

If we want cities that are resilient, inclusive, and sustainable, we need rules that embrace change rather than resist it. That means codes that are flexible, adaptive, and open to negotiation. It means shifting our gaze from facades to functions, from appearances to outcomes.

And perhaps, with the help of new technologies, it means letting go of the dream of perfect order altogether. Because in the end, the beauty of cities lies not in their conformity, but in their capacity to surprise.