eVolo Magazine recently announced the winners of its 2012 Skyscraper Competition, which range from compelling to whimsical to too clever by half. Meanwhile, here's a visionary skyscraper--not part of the competition--that's actually getting built.

The future of urban farming is under construction in Sweden as agricultural design firm Plantagon works to bring a 12-year-old vision to life: The city of Linköping will soon be home to a 17-story "vertical greenhouse."
the greenhouse is a conical glass building that uses an internal "transportation helix" to carry potted vegetables around on conveyors. as plants travel around the helix, they rotate for maximum sun exposure. [plantagon ceo hans] hassle says the building will use less energy than a traditional greenhouse, take advantage of "spillage heat" energy companies cannot sell, digest waste to produce biogas and plant fertilizers, and decrease carbon dioxide emissions while eliminating the environmental costs of long-distance transportation. and growing plants in a controlled environment will decrease the amount of water, energy, and pesticides needed.

The greenhouse is scheduled to open late next year. --b.d.s.