There's no question that San Francisco is currently in the midst of a housing shortage, and the city's limited space—along, of course, with extensive regulation and other factors—make it a tough place to build. Way back in 1991, Emeryville-based architect Eugene Tsui looked at how little space San Francisco had to offer and came up with a revolutionary vertical structure based on African termite mounds, the tallest non-manmade structures in the world. CityLab just took an in-depth look at this never-built concept, noting that Tsui's goal was to make San Francisco "a benchmark for ecologic living for the entire planet."
The concept for the building, known as the Ultima, was undoubtedly a bit far-fetched. It would have held the entire population of San Francisco, with a capacity of one million people. The whole purpose of the building was to get rid of sprawl and leave room for open space in the city. Tsui's design laid out 120 levels, each of which would have had its own mini-ecosystem of lakes, skies, hills, and rivers. Waterfalls on the lower levels combined with aerodynamic windows would have given the building a natural cooling system, and the surface would have been covered with photovoltaic solar. The whole thing would have been two miles high.
Despite all the benefits, getting all of the residents of San Francisco to agree to build and move into one building would be virtually impossible, especially in a city that has the propensity to hate any form of new building. Then there were the costs, which were estimated at $150 billion. There's probably no chance that a termite mound skyscraper for a million people will ever hit San Francisco. But at a time when the city is in desperate need of housing, maybe a mini-version of Tsui's concept isn't so crazy after all.
· The Visionary Mega-Tower That San Francisco Never Built [CityLab]
· The Ultima Tower [Tsui Design Research Inc]