Christmas may be over, but if designer Sir Norman Foster has his way, everyone in Moscow will be staring at a 1500ft tall, 27 million square foot, $4 billion dollar Christmas tree every day of the year. The structure, dubbed "Crystal Island" is being described as a "city within a building" and will feature 900 apartments, 3000 hotel rooms, an international school for 500 students, cinemas, a theater, a sports complex and more.

And because the developers are obviously all about being economical and eco-friendly, the building will generate electricity using exterior solar panels and wind turbines. It will also save money on heating using dynamic enclosure panels that can be adjusted to allow sunlight to enter deep into the structure.

Source- http://gizmodo.com/337853/worlds-biggest-building-coming-to-moscow-looks-like-it-will-be-christmas-year+round