30-story high-rise built in 15 days

Broad Sustainable Building built a 30-story high-rise in 15 days. That's bold: In 360 hours the company threw up a hotel with 350 guest rooms, plus amenities including a swimming pool and a helipad. BSB made plenty of waves with its construction process—basically a modular design stacked one story right on top of the next. But the company plans to make even more noise next year by building the world's tallest structure—220-story Sky City tower—in a mere 90 days.