Saturday, April 5, 2014

Euclidian zoning

If you took a little tour of North American suburbs from the air in an helicopter, or if you're cheap like me and go see aerial images from Bing Maps, you'd see something like this:
Typical Montréal suburb as seen from the air
Entire blocks full of single-family detached homes as far as the eye can see. Houses that are near identical, with extremely similar dimensions on very similarly sized lots. This is what most new constructions look like, and we accept it as the normal way of building neighborhoods, as if it was completely natural.

But behind these kinds of development is something we do not talk much about, which defines and strictly limits urban developments using the full force of the law. It is called zoning.

Zoning in North America is a municipal by-law that defines what can be built and where. There are many different types of zoning, but in North America, the typical zoning form is what is called euclidian zoning, from the city of Euclid, Ohio. This zoning is extremely strict when it comes to defining what can be built, the uses allowed in each zone and the dimensions of lots and buildings. The territory of cities is thus divided in a great amount of zones, each one having strict specifications.

Here is an example of this type of zoning, for one zone only, from the zoning bylaws of the Québec city of Saint-Jean-sur-Richelieu:
Example of zoning
If we represent graphically the minimum sizes, this is what we would have (1 meter = roughly 3,3 feet, 1 square meter = roughly 10 square feet)
The rules above represented graphically
The green represents the lot. On this lot, only a single-family detached home may be built, and only on the pale green zone, with the minimal dimensions shown in the red zone. This is for a one-story house, a two-story house may also be built, but on the same lot.

I feel that it is important to point out that in this form of zoning, generally single-family homes and multifamily homes are considered two separate uses to separate. Even semi-detached houses are considered different enough from detached houses that they are kept separate! In a lot of European and Asian zoning, this is not the case. Residential is residential. They don't treat multifamily residents as plague bearers to be kept separate from the good people who own detached houses.

This separation actually originates from racial segregation in the United States. At first, zoning explicitly banned certain races from settling in certain areas (who am I kidding? banned minorities from settling in white areas), but when this was ruled unconstitutional, they simply used different ways to achieve the same result. As minorities were poorer and largely rented housing instead of owning it, they simply banned multifamily buildings in single-family areas, and to avoid minorities from buying smaller, cheaper houses, they established minimum lot and building sizes.

This separation is pretty recent in Québec. Our old towns used to have a variety of housing built one next to the other, like this example from Sorel:

From left to right: semi-detached house, duplex and single-family detached house side-by-side, now illegal
Now back to Saint-Jean-sur-Richelieu's zoning:

Note how the zoning greatly limits possible density. By forbidding any type of multifamily housing, only one dwelling unit can be built per lot. And this lot is at minimum 450 square meters. So if there were no streets, parks or anything else but lots with houses on them, the maximum possible density would be 22 dwelling units per hectare (around 9 dwelling units per acre).

But you need streets to connect all those lots, and if the street is 9 meter wide with 1,5 meter sidewalks on each side, each lot would have 6 meters of street and sidewalk in front of it. Add lateral streets and maybe only 80% of the total area is actually lots, the rest being public right of way. So the maximum density is only around 17,5 dwelling units per hectare (7 dwelling units per acre)

And again, that's MAXIMUM density. In reality, lots may be bigger and density even smaller.

How many of these zones exist in Saint-Jean-sur-Richelieu? Well, this 100 000-people city has hundreds of them, more than a thousand actually, zones that are similarly defined. Here is an image from their zoning map, only a small part of it, with each individual lot identified:

Map of current zones in a sector of Saint-Jean-sur-Richelieu
The darker lines represent the borders between zones, and each zone is identified with a code written in gold, like "H-2572". Most zones seem to have only 15 to 50 lots in residential areas, even less in commercial areas. But there are a few exceptions, like H-2748 which has one (!) lot.

All buildings that do not respect the zoning rules are forbidden, unless the city council grants a minor derogation or changes the zoning, which starts a process in which local residents may oppose the change.


Why such zoning practices?


Euclidian zoning is favored because, despite its apparent complexity, it is very simple to enforce. You simply measure dimensions and see if they measure up to refuse or accept building permits. This type of zoning is all about micromanagement, but though it can be used for planning, it is extremely poor in macromanagement and planning decent communities. It satisfies those with a great desire to control the built area of their immediate neighborhood.

Those who support it underline the "harmony" that results from it, and the certainty given to residents that the neighborhood will not change much once it is built up. If you buy a house on a street, there are few chances you will say anything else but houses on that street for as long as you live.


The disastrous consequences of euclidian zoning


The result is an incredible mess. All modifications, even for a few inches, requires derogations which can be contested by neighbors and create a zoning conflict than can delay projects by months, even years, or maybe even kill it... even if the project is someone who wants to build a porch for his house.

This zoning strangles redevelopment and keeps neighborhoods in formaldehyde, forbidding people from building anything that is not identical to what is already built in the area. But in order to grow, cities must evolve. One can argue that change has to be domesticated to avoid problems resulting from too much change too quickly, but euclidian zoning in practice basically makes change illegal, and there is no defense for that.

It also is the ultimate empowerment tool for NIMBYs, giving them ways to veto anything. That's why urban developments in North America are based on sprawl. As built-up areas are already zoned and obstacles to change this zoning are varied and numerous, promoters will rarely make projects to densify urban neighborhoods. Even when they do, making duplexes, triplexes or rowhouses in single-family areas are often not worth it in view of their relatively low profits and the cost of confronting local NIMBYs, so where they will confront NIMBYs is when they want to build condo towers, because the profit then justifies fighting for the right to build them. Yet, the duplexes and rowhouses would actually be a better evolution, a more gradual progression from suburban to urban neighborhoods.

Promoters stuck in this disastrous zoning will also favor building new housing on the outskirts of everything, where there is no resident to oppose new developments.

That's why we see more and more condos being built on the outskirts of suburbs, next to highways. These condos, though perfect for the city centers, are generally illegal in most neighborhoods. So they are built in areas often apart from anything else, which doesn't help fight car-dependence, as density needs proximity to be really beneficial.

There is also a strong impact on land values. If everything was allowed everywhere, choice lots in the center of cities would quickly see commercial and multifamily developments, because the profit per square foot of these uses is much higher than for single-family developments. For instance, if a single-family home costs 200 000$ to build and sells for 350 000$, and the promoter wants to make at least 100 000$ in profit, then that leaves only 50 000$ to buy the lot. On the other hand, a 3-story condo development on the same lot may have 6 units, which cost overall 600 000$ to build but will sell for 1 000 000$, to keep 100 000$ in profit, the promoter will be able to spend 300 000$ on buying the lot.

So if there is a lot near transit links, high-density developments would quickly win the auction for that lot, promoters who want to build single-family houses would just not be able to keep up with the prices other promoters would, resulting in natural transit-oriented development without the need of TOD planning from local authorities.

But if the land is reserved only for single-family detached houses, then the profit value of each square foot is kept artificially low, and thus the value of the land will be reduced, simply because more profitable uses for it will be forbidden.

The worst thing is that cities often stubbornly want to zone things for single-family detached housing. The result is an oversupply of single-family lots, which further depresses the value of the land, making single-family homes more affordable. However, there is a shortage of lands for multifamily developments and for commercial developments, the land zoned to allow them is thus much more expensive than it should be, making such projects more expensive. So it makes single-family homes more affordable by making alternative, denser housing types more expensive. Then people start thinking that it's natural that single-family homes be more affordable, when it's the result of absurd zoning practices.

There is a final consequence of such zoning: corruption.

When there is an highly profitable project that is blocked by zoning, you need a zoning modification to let it through. But this zoning change is subjected to the approval of elected officials who receive pressures from NIMBYs opposed to any zoning change. So promoters have an incentive to get friendly with the elected officials and to cajole them into passing the zoning change despite local opposition. It's not that the promoters like to corrupt people, but when you make it impossible to make a profit by following the rules, you incite people to go around them. I'm sure most of them would prefer not having to spend money buying politicians.

The problem is that the current zoning system makes corruption much more likely.

Next, I'll describe an alternative: the Japanese zoning system, which corrects many of these issues.


  1. This type of zoning in effect requires the use of cars as there are no corner stores and virtually no-one can live within walking distance of their employment. It locks inefficiencies into the system.

    1. Thank you, you've just explained why General Motors was so heavily invested in urban planning and zoning laws.