Solar Envelope and the Ideal City

 

The International Living Building Institute is asking for submissions for the Living City Design Competition - Visualizing the Future of Civilization. I have many reservations about the premise of the competition-- I think that cities are not a result of Utopian planning but the slow and aggregate change of history guided by decentralized processes and relationships between millions of people.

Typically these competitions produce awesome but totally unrealistic visions that have no hope of being realized. Some of the best cities in the world are very conservative by the standards of these types of competitions -- they are made up of mid-rise, mixed use buildings that have a strong culture and a long history, like Sienna. But many of these are tightly-packed since they originally existed within a protective wall, and didn't have such things as urban forest, bioswales, green roofs, etc.

It has still got me thinking, what does a sustainable city really look like? I think a good starting point is to think about how natural light and passive heating suggest the ideal form of a building. The Solar Envelope by Ralph Knowles is a good starting point, this shows how buildings should reside within a form that prevents them from shading neighboring buildings or the street most of the time. I theorized that there is a plateau to the ideal density of a city-- a point at which the desirability of density meets the ability for us to enjoy direct sunlight, ambient natural light, private and public outdoor space, etc.

I gave myself the project of designing a condominium building in Portland's rotated 200 x 200 ft block grid in which each resident could enjoy direct solar exposure during the winter; lots of natural light, a private backyard that doubles as a green roof.

 

Some of the most interesting problems with city design is how to give people some of the basic connections to nature that exist in the suburbs, such as a sunning deck, a place for a small garden, views to trees, etc. Even just the ability to walk around outside in the sun is a basic connection to nature that is lacking in many Utopian proposals for cities, which usually involve giant high-rises.

There are lots of reasons for mid-rise buildings; that they create a strong connection to the street; they allow sunlight to reach the street; and this is the maximum height at which a fire department can rescue someone from a burning building. If these buildings successfully integrate a mix of uses and connect well to the street then you can create a vibrant street life that is essential to any city.

And you might be surprised that although the downtown core of a city greatly exceeds this level of density, most of Portland is below this density. So density does not necessarily mean that we have to pack ourselves into skyscrapers.

I hope you enjoyed this imaginative exercise!

Brett