*This article is based on information as of December 2025.

1. The Geometry of Wind and Streets: Rome in Flee, Hokkaido in Opposition

When planning a city, what should be considered first? Is it the price of land or the accessibility of transportation? Vitruvius' answer was something more fundamental: the wind.

Vitruvius' warning: "Don't invite the wind in"

In the sixth chapter of Book 1 of his Ten Books on Architecture, "On the Direction of the Streets and the Winds," Vitruvius writes that the first step in urban planning is to divide the streets within the city walls."You can't have the streets facing the wind."He strongly asserts that:

According to his theory, wind is a "flowing wave of air," and although its movement is invisible, it is a physical force that determines the sanitary environment of a city. What would happen if a street were designed to face the direction of the prevailing wind (the wind that blows most frequently) in the area? The street itself would become what physics calls a "wind tunnel."

The wind, blowing through the straight, unobstructed roads, penetrates deep into the city without slowing down. Vitruvius warned:

• "Cold winds are uncomfortable and make life difficult."
• "Hot winds weaken people."
• "Damp wind is bad for your health."

He therefore recommended orienting streets "in the middle" of the main wind direction, i.e., orienting them so that the wind hits the corners of buildings (block corners), thereby breaking up and diffusing the force of the wind and preventing it from blowing directly into alleys and houses. This can be said to be a precursor to what is called "passive design" in modern environmental engineering.

He actually cited the city of Mytilene on the island of Lesbos as an example, criticizing it for lacking "prudentia" (care) in its layout planning, no matter how beautifully and magnificently constructed it may have been. His description of how "when the south wind blew, people fell ill; when the northwest wind blew, they coughed; when the north wind blew, they recovered, but the bitter cold made it impossible for them to even stand in the streets and alleys" seems to predict the scene of a modern-day winter in Sapporo.

Hokkaido's fight against snow and the trade-offs it has made

Now, let's look at the major cities of Hokkaido that were built after the Meiji period, particularly Sapporo. Planned by the Hokkaido Development Commission, this city is a typical grid city (goban-style) that is precisely based on the cardinal directions of north, south, east, and west.

From a Vitruvian perspective, this is an extremely "risky" layout because the long, straight streets face directly or at an angle to the northwesterly monsoons that prevail in Hokkaido in winter, maintaining the wind speed and drawing cold air into the city.

So why did the pioneers of Hokkaido choose this structure? There was a variable unique to northern regions that Vitruvius had not anticipated: snow accumulation.

In Hokkaido's urban planning, the top priority in winter is not "wind control" but "maintaining traffic functions," i.e."Snow removal efficiency"Let's check the comparison in the table below.

What would have happened if roads had been constructed in complex, winding patterns to protect from the wind, as Vitruvius taught? Huge modern snowplows and snow removal trucks would not have been able to operate smoothly, and managing snow dumps (snow belts) would have been extremely difficult. Straight, clear roads were an essential requirement for maintaining lifelines in snowy regions.

Instead, modern cities have achieved Vitruvian "shelters" in other ways. These include the development of "underground walking spaces (chi-ka-ho)" that completely block winds above ground, and "architectural defenses" that improve the insulation performance of individual buildings. Instead of blocking the wind with urban structures, they protect people with a membrane of technology. This was Hokkaido's answer.

2. Managing Beauty (Venustas): From Order to Munsell Values

Next, we will consider one of Vitruvius' three principles, "beauty (Venustas)." In modern times, "beauty" tends to be perceived as subjective, but in ancient Rome, it was based on strict mathematical rules.

The dignity of the landscape protected by "10YR 2/1"

Let's take a look at Toyako Town's "Landscape Guidelines" in detail. These specify the colors that can be used on the exterior walls of buildings in great detail using Munsell values, which indicate hue, value, and saturation.

For example, low-saturation (reduced vividness) colors such as "10YR 2/1" are recommended, and conversely, highly saturated primary colors such as red and yellow are generally discouraged. This is a system that puts a stop to commercial signs and architecture that aim to "stand out" within a public framework.

At first glance, this may seem like an excessive restriction on freedom of expression, but just as Vitruvius emphasized the importance of order in public spaces, saying that "temples must have the dignity to be looked up to from anywhere in the town," in Toyako Town, Mt. Yotei, Nakajima Island, and the lake surface itself serve as modern-day temples.

By limiting the height of buildings and unifying the colors to earth tones, the man-made city will blend into the magnificent natural scenery. This is a modern redefinition of "beauty (Venustas)" and the implementation of a highly intellectual design code.

3. Utilitas and Firmitas: Urban Theory of Circulation and Regeneration

Finally, we will explore the surprising similarities and differences between Rome and Toyako Town in terms of urban functionality (Utilitas) and structural strength (Firmitas).

Modern Aqueduct: Centralized Hot Spring Management System

Roman civilization is also known as the "civilization of water." Vitruvius devoted the entirety of Book 8 to water, detailing methods for discovering water sources, testing water quality, and supply systems using long aqueducts. His perspective was even medical, as he even mentioned the potential health hazards of lead pipes (lead poisoning) and recommended the use of ceramic pipes. This is because the fair distribution of water infrastructure is the foundation of a city's functionality (Utilitas).

This spirit continues to be felt in modern Toyako Onsen."Hot spring centralized management hot water distribution system"During the tourism boom of the high economic growth period, hotels competed to drill their own hot springs, which led to a drop in water level and the risk of resource depletion. To prevent this "tragedy of the commons," the town took control of the hot springs and built a system to distribute the hot water to each facility through a huge pipeline.

Furthermore, modern technology has surpassed the Roman ideal. According to documents such as the Toyako Town Waterworks Management Strategy, a system has been introduced to recover and reuse thermal energy from used hot spring wastewater using a heat pump. Resources are not used once and then thrown away, but are thoroughly recycled. This can be said to be an update of ancient wisdom with modern environmental ethics (sustainability).

Strength isn't about not breaking, it's about being able to bounce back

And here in Toyako Town, there is a crucial difference in the concept of "strength (Firmitas)."

Vitruvius aimed to build an "eternal city" that would remain unchanged for hundreds of years by placing the foundations of the building on solid ground and using permanent stone and brick. For him, unstable land (swamps and soft ground) was merely a risk to be avoided.

However, Toyako Town is located at the foot of Mount Usu, an active volcano. Eruptions occur here every few decades (in the 20th century alone, in 1910, 1944, 1977, and 2000), causing the earth itself to rise and change shape. No matter how strong the stonework, it is powerless against the overwhelming power of magma.

The answer that Toyako Town gave to this inevitable fate was something that was unique in the world."Preservation of disaster remains"is.

• The demolished public housing will remain as it is.
• The raised roads and curved railway tracks will be developed into walking paths.
• Plants sprouting from the ruins are shown as a "symbol of rebirth."

This is a dramatic shift from Roman values that sought to conquer and control nature. Based on the premise that "disasters cannot be prevented," even memories of destruction are incorporated as part of the city's identity (assets). The Toyako-Usuzan Geopark's philosophy of "coexistence with the ever-changing earth" teaches us that true "strength" in the modern world lies not in robustness, but in resilience.

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