Soft City: Layering Life

As we strive for sustainability and resilience in urban environments, is it possible to take inspiration from natural environments? In nature, there are systems that accommodate density and diversity in sustainable ways and have proven to be resilient.

A forest is much more than a big group of trees. It a complex symbiotic system that sustains the life of a wide range of species in different scales and situations. The forest offers habitat for a wide range of lifeforms—plants and micro-organisms, animals and birds. Forests are some of the most biologically rich ecosystems on the planet.

A characteristic of the forest is a distinct horizontal system of layering life. The life around the ground is different from the life in the branches, which is different from the life in the tree tops. There are different physical realities—dark places connected to the earth, light spaces connected to the sky, more protected places and those that are more exposed, and everything in between. The layering of these different micro environments enable different forms of life to exist and even thrive in the same place.

Different species of trees may grow next to each other. Each tree creates its own environment and microclimate. The space between trees creates a unique environment, a product of both. In this way, the whole is greater than the sum of the parts.

What we know from the forest is that diversity is the key to sustainability. When the forest is attacked by fire, storm, or pests, it is resilient because the component parts can respond in different ways. Lightning can strike and a fire can start or bugs and disease can land, and even if a tree or two might be lost, or one species might suffer, the forest as a whole lives on. The forest demonstrates the potential for the collocation of different elements, creating a system where the interrelationships let life flourish in the in-between.

Compared with the natural forest, a plantation of trees is very different. Here there are no layers of different life forms. There is generally only one species. There is no difference created between trees, and the whole remains the same as the sum of its parts. We know from the need for pesticides, the higher rate of destruction in storms, and the strict fire and flood precautions, that the planted woodland is more vulnerable than the natural forest.

It was while reading about the differences between natural forests and planted woodland that I was struck by the possible parallel in the built environment. Are there towns and cities that have the resilient characteristics of natural forests and others which are more like vulnerable plantations?

The layers of different life seen in the traditional French apartment block are not unlike those in the natural forest. This drawing reveals the functional, social and economic diversity that one building can accommodate.

The illustrator has tried to express the failings of society by exposing the innards of the city and the economic segregation of people. However, there may be another way of reading this illustration. What is truly significant is that all these different people share the same address. They all live under the same roof. The minute they step out of their apartment doors they are neighbors and the minute they step out of the building onto the street, they are part of the same community and have access to the assets of the city that might be found close by.

If this kind of diversity can be accommodated in one building, even more can be accommodated in one block, as the pattern is repeated. Therefore, it is possible for people with different abilities, needs, finances, and backgrounds, and at different points in their lives to all live as neighbors. It seems with most iterations of formal planning, even long before Modernism, there has been a tendency to try and make the human built environment in something tidier, which has almost always involved the separation of different people and uses. Unlike the people in the French drawing, today people who are economically different from each other generally live many kilometers apart.

Is there a parallel between the natural forest and the traditional town or city? Just as the forest is not just a big group of trees, the city is not just a big group of buildings. In both cases the total is greater than the sum of the parts. When it performs best, the city can also be a symbiotic and sustainable system for accommodating a great diversity of life.

Like the trees, the buildings can have distinct and different layers—the ground plane is the busiest and most concentrated, then there is the relative calm of the middle floors, and the special place at the top level, like the tree tops, where the buildings meet the sky. Are the segregated zones of Modernist planning; the social housing estates, the gated communities, the business parks, and the shopping malls the urban equivalent of the tree plantation?

Like life in the forest, urban life is in constant change. The local complexity provided by spatial layering and juxtaposition can allow a town or city to adapt and accommodate to the ever-evolving changes of life.

This is an excerpt from the book ‘Soft City: Building Density for Everyday Life,’ written by former Creative Director and Partner David Sim with support from Gehl and Realdania.