From the vault: Chinese towers and American blocks
The difference comes down to regulation, not culture.
This article originally appeared in the latest issue of Works in Progress, Issue 18. You can read this article on our website and the rest of the issue here.
Inasmuch as people think about differences in urban form between countries, they tend to assume these are a matter of ‘culture’, either of buyers, architects, or developers. And sometimes, this is true. For example, most English urban developments in the nineteenth century were terraced houses, whereas most Scottish ones were flats, though there were no laws requiring this and though the two countries were similarly wealthy.
But very often, differences in urban form are the result of regulation. This has become increasingly true over time, as it has become increasingly common for rules to constitute the binding constraint on built volume. Today, it is frequently the case that the built form of a neighborhood can be predicted with almost algorithmic accuracy from the regulations that it is subject to.
If culture plays a role at all, it is through shaping regulation, not through shaping consumer preferences. But even this can be overrated: building regulations are technical documents written by tiny groups of professionals, and the same background culture can often coexist with a wide range of different regulatory systems.
We can understand this by looking at the cities of the world’s two leading economies, China and the United States. The cities of China and the United States look very different. The tall residential towers typical of Beijing or Chongqing have little in common with the squat mid-rise apartments preferred across the United States, in those cases where the US does build apartments rather than single-family homes.
It is natural to assume that there is some ‘deep’ cultural explanation for this. But it is not clear that this is so. In fact, US apartment urbanism is closer to Hong Kong, Taiwan, and Macau than Chinese apartments are. Rather than reflecting consumer preferences or a unique aesthetic heritage, the answer seems to mostly come down to zoning rules and building codes.
Back to basics: understanding floor area ratio
High-rises are new to China. Few were built until the economic and urbanization boom of the 1990s, but since then, they have become the standard Chinese home. In 2015, half of the population – including most people in urban areas – lived in a high-rise. Today, that percentage continues to grow as more people move from the countryside to cities.
In contrast, apartments comprise only a small portion of the US housing market. Two thirds of all homes in the US are detached dwellings, and most have been around for a while; the average home in the US is over 40 years old. However, in large cities, where land is scarce, most new residential structures are apartments – comprising, for example, 75 percent of all new homes in the Bay Area. Of those new apartments, most are in large mid-rise buildings.
Despite their strong visual dissimilarities, new construction in China and the US share one basic feature: they each support roughly the same population density, as their floor area ratio is similar.
The floor area ratio, or FAR, is calculated by dividing the area of all of a building’s floors by the area of the entire parcel of land the building sits on, including any internal roads. It is the measure of how much building there is in a given space, a measure of built density.
Population density and the density of dwellings per acre or hectare are both useful metrics. But pro-housing advocates should not take them as objectives because both of them can be achieved by cramming more people into the same amount of floorspace or subdividing the same amount of floorspace into smaller dwellings. FAR just measures how much usable floor space there is on a given plot or development. It can be split into dwellings based on population demand and income.
Zoning regulations typically rely on gross FAR, which includes all indoor above-ground space, in contrast to net FAR, which only includes the apartments themselves and excludes hallways, lobbies, or other service spaces.
When it comes to city planning, a building’s height is not always a good measure of its density: a short building that covers a whole lot can have the same amount of indoor space as a tall building that only covers part of a lot. For example, a single-storey building that covers an entire lot has a floor area ratio of 1.0, but a two-storey building that covers half the lot would also have a floor area ratio of 1.0.
Typical floor area ratios range from 0.1 for single-family homes built on half-acre lots to 12, indicating high-rises of 30 stories or more, of the type only found in populous downtowns. (The Empire State Building has a floor area ratio of 31, but this sort of density is rarely economical or permitted.) This has profound implications for the features and amenities of a neighborhood. The exurban density of FAR 0.1, for example, means that residents almost always rely on cars for transportation, as there aren’t enough people to support public transit or any sort of business within walking distance.
In between these two extremes are a range of other housing types.
A density of FAR 0.4 forms the backbone of the classic American suburb: houses with front, back, and small side yards, possibly linked up to the urban center by basic transit on the order of a single bus line.
FAR 1.5 indicates row houses and garden apartments – think of the less-dense neighborhoods in Brooklyn, Richmond in London, or the terraces of the Hague and Copenhagen. Generally served by more robust public transit, as traffic congestion is a given, usually, there is a variety of retail within walking distance or a short ride away on public transit.
FAR 4.0 is the density at which mid-rise apartment blocks or high-rise towers appear. It is difficult for everyone to live at this density and yet rely on cars for transport, as it would require setting out unaffordable acres of tarmac for parking and to accommodate all the traffic. Good public transit is a must, and retail serving residents’ daily needs is all within walking distance.
You can read the rest of the piece here.
Alfred Twu is a Commissioner-Elect on Berkeley's Rent Board, a California Democratic Party delegate, an architect in the East Bay and a commercial artist. Follow them on Twitter.
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