I think stairs may be

one of the most emotionally malleable physical elements

that an architect has to work with.

[Small thing. Big idea.]

[David Rockwell on the Stairs]

At its most basic, a stair is a way to get from point A to point B

at different elevations.

Stairs have a common language.

Treads, which is the thing that you walk on.

Riser, which is the vertical element that separates the two treads.

A lot of stairs have nosings that create a kind of edge.

And then, the connected piece is a stringer.

Those pieces, in different forms, make up all stairs.

I assume stairs came to be from the first time someone said,

"I want to get to this higher rock from the lower rock."

People climbed using whatever was available:

stepped logs, ladders

and natural pathways that were worn over time.

Some of the earliest staircases, like the pyramids in Chichén Itzá

or the roads to Mount Tai in China,

were a means of getting to a higher elevation,

which people sought for worship or for protection.

As engineering has evolved, so has what's practical.

Stairs can be made from all kinds of material.

There are linear stairs, there are spiraled stairs.

Stairs can be indoors, they can be outdoors.

They clearly help us in an emergency.

But they're also a form of art in and of themselves.

As we move across a stairway,

the form dictates our pacing, our feeling, our safety

and our relationship and engagement with the space around us.

So for a second, think about stepping down a gradual, monumental staircase

like the one in front of the New York Public Library.

From those steps,

you have a view of the street and all the people around you,

and your walk is slow and steady because the tread is so wide.

That's a totally different experience

than going down the narrow staircase to, say, an old pub,

where you spill into the room.

There, you encounter tall risers, so you move more quickly.

Stairs add enormous drama.

Think about how stairs signaled a grand entrance

and were the star of that moment.

Stairs can even be heroic.

The staircase that remained standing after September 11th

and the attack on the World Trade Center

was dubbed the "Survivors' Staircase,"

because it played such a central role in leading hundreds of people to safety.

But small stairs can have a huge impact, too.

The stoop is a place that invites neighbors to gather,

blast music, and watch the city in motion.

It's fascinating to me that you see people wanting to hang out on the stairs.

I think they fill a deeply human need we have

to inhabit a space more than just on the ground plane.

And so if you're able to sit halfway up there,

you're in a kind of magical place.