So many things changed after the 2001 terror attacks on the World Trade Center and Pentagon, and one area where that's especially true is building design and construction. NY1's Adam Balkin filed the following report.

"New York City, and cities in general, are shaped significantly by disasters," said Georg Windeck, an architect and professor at The Copper Union.

From the Great Chicago Fire, to California earthquakes, to, of course, 9/11, Georg Windeck —author of "Construction Matters" — says so much you see in the skyscrapers around you is a response of some sort to a natural or manmade disaster.

Pre-9/11, the primary threat in New York that was taken into account was fire — how best to contain them and evacuate in the event of one.

Post-9/11, however, after seeing massive impacts and buildings crumble, those too had to be designed for; in particular, how to get people who are inside out as quickly as possible.

So lots of the focus is now on stairs.

"Prior to 9/11, skyscraper architecture, the idea was always that you keep the core of the building as compact as possible," Windeck said. "So you may have two staircases, but they're right next to each other, so in the case that core is compromised there's no other way of getting out of the building.

"Now the idea would be that you have staircases placed in different locations in the floor plan."

Stairs and sprinkler systems are also now solidly encased so that they're fire- and blast-proof. 

And that list goes on and on and on, not just for advancements in building techniques but also for advancements in building materials.

New types of glass are blast-resistant; some new concretes are as strong as steel; and safety concrete bends and cracks but doesn't break and send pieces flying in the event of an impact.

And there's a third element here too, according to City College professor Lance Brown: location.

"You design a building, you always want to take into account its orientation to the sun, you want to take into account the wind tunnel issues, you want to take into account many, many things," Brown said.

"This adds that layer, if you want to take into account levels of security that you may heretofore not have considered," Brown continued. "Looking at traffic patterns, where vehicles might come and accelerate and find ways in and speed."

And Professor Brown insists the next disaster that's already factoring into future building designs is a disaster that's ongoing: global warming.