I can't imagine it could work for an old structure with little glass but it is an interesting use of urban land.


From Scientific American: Growing Skyscrapers: The Rise of Vertical Farms
Key Concepts:
  • Farming is ruining the environment, and not enough arable land remains to feed a projected 9.5 billion people by 2050.
  • Growing food in glass high-rises could drastically reduce fossil-fuel emissions and recycle city wastewater that now pollutes waterways.
  • A one-square-block farm 30 stories high could yield as much food as 2,400 outdoor acres, with less subsequent spoilage.
  • Existing hydroponic greenhouses provide a basis for prototype vertical farms now being considered by urban planners in cities worldwide.
Together the world’s 6.8 billion people use land equal in size to South America to grow food and raise livestock—an astounding agricultural footprint. And demographers predict the planet will host 9.5 billion people by 2050. Because each of us requires a minimum of 1,500 calories a day, civilization will have to cultivate another Brazil’s worth of land—2.1 billion acres—if farming continues to be practiced as it is today. That much new, arable earth simply does not exist. To quote the great American humorist Mark Twain: “Buy land. They’re not making it any more.”...