Imagine that when you walked in here this evening,
you discovered that everybody in the room
looked almost exactly the same:
ageless, raceless,
generically good-looking.
That person sitting right next to you
might have the most idiosyncratic inner life,
but you don't have a clue because we're all wearing
the same blank expression all the time.
That is the kind of creepy transformation
that is taking over cities,
only it applies to buildings, not people.
Cities are full of roughness and shadow,
texture and color.
You can still find architectural surfaces of great individuality and character,
in apartment buildings in Riga
and [???].
social housing in Vienna,
Hopi villages in Arizona,
brownstones in New York,
wooden houses in San Francisco.
These aren't palaces or cathedrals.
These are just ordinary residences
expressing the ordinary splendor of cities.
And the reason they're like that
is that the need for shelter
is so bound up with the human desire
for beauty.
Their rough surfaces give us
a touchable city.
Right? Streets that you can read by running your fingers
over brick and stone.
But that's getting harder to do,
because cities are becoming smooth.
New downtowns sprout towers that are almost always made
of concrete and steel
and covered in glass.
You can look at skylines all over the world --
Houston, Guangzhou,
Frankfurt --
and you see the same army of high-gloss robots
marching over the horizon.
Now just think of everything we lose
when architects stop using the full range
of available materials.
When we reject granite
and limestone and sandstone and wood and copper
and terra cotta and brick
and wattle and plaster,
we simplify architecture
and we impoverish cities.
It's as if you reduced all of the world's cuisines
down to airline food.
(Laughter)
Chicken or pasta?
But worse still,
assemblies of glass towers like this one in Moscow
suggest a disdain for the civic and communal aspects of urban living.
Right? Buildings like these are intended to enrich their owners and tenants,
but not necessarily the lives of the rest of us,
those of us who navigate the spaces between the buildings.
And we expect to do so for free.
Shiny towers are an invasive species,
and they are choking our cities and killing off public space.
We tend to think of a facade
as being like makeup,
a decorative layer applied at the end to a building that's effectively complete.
But just because a facade is superficial
doesn't mean it's not also deep.
Let me give you an example
of how a city's surfaces affect the way we live in it.
When I visited Salamanca in Spain,
I gravitated to the Plaza Mayor
at all hours of the day.
Right? Early in the morning, sunlight rakes the facades,
sharpening shadows,
and at night, lamplight segments the buildings into hundreds
of distinct areas,
balconies and windows and arcades,
each one a separate pocket of visual activity.
That detail and depth, that glamour
gives the plaza a theatrical quality.
It becomes a stage where the generations can meet.
You have teenagers sprawling on the pavement,
seniors monopolizing the benches,
and real life starts to look like an opera set.
The curtain goes up on Salamanca.
So just because I'm talking about the exteriors of buildings,
not form, not function, not structure,
even so those surfaces give textures to our lives,
because buildings create the spaces around them,
and those spaces can draw people in
or push them away.
And the difference often has to do with the quality of those exteriors.
So one contemporary equivalent of the Plaza Mayor in Salamanca
is the Place de la Défense in Paris,
a windswept, glass-walled open space
that office workers hurry through
on the way from the Metro to their cubicles
but otherwise spend as little time in as possible.
In the early 1980s, the architect Philip Johnson
tried to recreate a gracious European plaza in Pittsburgh.
This is PPG Place,
a half acre of open space encircles by commercial buildings
made of mirrored glass.
And he ornamented those buildings
with metal trim and baize
and gothic turrets
which really pop on the skyline.
But at ground level,
the plaza feels like a black glass cage.
I mean sure, in summertime kids are running back and forth
through the fountain
and there's ice skating in the winter,
but it lacks the informality of a leisurely hangout.
It's just not the sort of place you really want to just hang out and chat.
Public spaces thrive or fail for many different reasons.
Architecture is only one,
but it's an important one.
Some recent plazas
like Federation Square in Melbourne
or Superkilen in Copenhagen
succeed because they combine old and new,
rough and smooth,
neutral and bright colors,
and because they don't rely excessively on glass.
Now, I'm not against glass.
It's an ancient and versatile material.
It's easy to manufacture and transport
and install and replace
and clean.
It comes in everything from enormous, ultra-clear sheets
to translucent bricks.
New coatings make it change mood
in the shifting light.
In expensive cities like New York, it has the magical power
of being able to multiply real estate values by allowing views,
which is really the only commodity that developers have to offer
to justify those surreal prices.
In the middle of the 19th century,
with the construction of the Crystal Palace in London,
glass leapt to the top of the list of quintessentially modern substances.
By the mid-20th century,
it had come to dominate the downtowns of some American cities,
largely through some really spectacular
office buildings like Lever House
in midtown Manhattan, designed by Skidmore, Owings and Merrill.
Eventually, the technology
advanced to the point where architects could design structures so transparent
they practically disappear.
And along the way,
glass became the default material of the high rise city,
and there's a very powerful reason for that,
because as the world's populations converge on cities,
the least fortunate pack into jerrybuilt shantytowns,
but hundreds of millions of people need apartments and places to work
in ever larger buildings,
so it makes economic sense to put up towers
and wrap them in cheap and practical curtain walls.
But glass has a limited ability
to be expressive.
This is a section of wall framing a plaza
in the pre-Hispanic city of Mitla, in southern Mexico.
Those 2,000-year old carvings
make it clear that this was a place of high ritual significance.
Today we look at those and we can see a historical and textural continuity
between those carvings, the mountains all around,
and that church which is built on top of the ruins
using stone plundered from the site.
In nearby Oaxaca, even ordinary plaster buildings
become canvasses for bright colors, political murals,
and sophisticated graphic arts.
It's an intricate, communicative language
that an epidemic of glass would simply wipe out.
The good news is that architects and developers
have begun to rediscover the joys of texture
without backing away from modernity.
Some find innovative uses for old materials like brick
and terra cotta.
Others invent new products like the molded panels
that Snøhetta used
to give their San Francisco Museum of Modern Art
that crinkly, sculptural quality.
The architect Stefano Boeri even created living facades.
This is his Vertical Forest, a pair of apartment towers in Milan,
whose most visible feature is greenery.
And Boeri is designing a version of this for Nanjing in China.
And imagine if green facades were as ubiquitous as glass ones
how much cleaner the air in Chinese cities would become.
But the truth is that these are mostly one-offs,
boutique projects,
not easily reproduced at a global scale.
And that is the point.
When you use materials that have a local significance,
you prevent cities from all looking the same.
Copper has a long history in New York --
the Statue of Liberty,
the crown of the Woolworth Building --
but it fell out of fashion for a long time
until shop architects used it to cover the American Copper Building,
a pair of twisting towers on the East River.
It's not even finished and you can see the way sunset
lights up that metallic facade,
which will weather to green as it ages.
Buildings can be like people.
Their faces broadcast their experience.
And that's an important point,
because when glass ages,
you just replace it,
and the building looks pretty much the same way it did before
until eventually it's demolished.
Almost all other materials have the ability to absorb
infusions of history and memory
and project it into the present.
The firm Ennead
clad the Utah Natural History Museum in Salt Lake City in copper and zinc,
ores that had been mined in the area for 150 years
and that also camouflage the building against the ochre hills
so that you have a natural history museum
that reflects the region's natural history.
And when the Chinese Pritzker Prize Winner Wang Shu
was building a history museum in Ningbo,
he didn't just create a wrapper for the past,
he built memory right into the walls
by using brick and stones and shingles
salvaged from villages that had been demolished.
Now, architects can use glass
in equally lyrical and inventive ways.
Here in New York, two buildings,
one by Jean Nouvel and this one by Frank Gehry
face off across West 19th Street,
and the play of reflections that they toss back and forth
is like a symphony in light.
But when a city defaults to glass
as it grows,
it becomes a hall of mirrors,
disquieting and cold.
After all, cities are places of concentrated variety
where the world's cultures and languages and lifestyles
come together and mingle.
So rather than encase all that variety
and diversity in buildings of crushing sameness,
we should have an architecture that honors
the full range of the urban experience.
Thank you.
(Applause)