Many technological advancements have changed the way we design in the past 150 years, but perhaps none has had a greater impact than the invention of the passenger elevator. Prior to Elisha Otis’ design for the elevator safety brake in 1853, buildings rarely reached 7 stories. Since then, buildings have only been growing taller and taller. In 2009, the world’s tallest building, the Burj Khalifa, maxed out at 163 floors (serviced by Otis elevators). Though a century and half separates those milestones, in that time elevator technology has actually changed relatively little - until recently.