http://www.theatlanticcities.com/design/2012/08/there-limit-how-tall-buildings-can-get/2963/
"We could do at least a mile and probably quite a bit more."
Is There a Limit to How Tall Buildings Can Get?
Atlantic Cities Nate Berg examines skyscrapers how high is possible? I think we long ago surpassed the height that is bad for a city.