“There is a limit – but it’s today’s limit, not a future limit,” says Jeff  Smilow, director of building structures at WSP in the USA. Innovation and evolution in a whole range of technologies, from damper systems to high-strength materials, will enable designers to create higher and higher building structures. “There are always new technologies. If you talked to engineers 50 years ago or 70 years ago, you’d get a different answer than today.” What about a theoretical limit past which  technology can’t take us? “You could find some very abstract limits on the strength of materials, but we are far away from reaching those limits,” adds Dr Ahmad Rahimian, director of building structures at WSP in the USA. “People’s aspiration, or the lack of it, is the real limit.”