The definition of what it means to be sustainable in the 21st century needs to be broadened to include a skyscraper's ability to sustain the human spirit, says Hao Ko, a design director at Gensler.

"Imagine energy efficient towers whose walls might slide open, allowing office workers to step outside, into the sky, for a breath of fresh air. Towers where seasonal gardens grow vertically and where friends might meet by a kumquat tree on the 68th floor for a cup of coffee on a beautiful spring day."

Buildings such as Manitoba Hydro Place in Winnipeg, Canada, and the KfW Bank Headquarters in Frankfurt, Germany, have led this next generation of sustainable towers.

Gensler‘s Shanghai Tower is next. Slated to be the second-tallest building in the world, it incorporates these positive ideals within the clear walls.

(READ the full story from the FastCoExist)