Original subtitles

[Male Narrator] How do you build an airport so futuristic

that it's more rainforest than runway?

There is no other airport terminal building like this

anywhere.

[Narrator] Why does a New York skyscraper

take 80 years to finish?

[Norman] It was open, published speculation,

that was the end of the tall building.

[Narrator] And how do you build a gallery as extraordinary

as the art it holds in the middle of a hurricane hotspot?

We've got 150-mph winds

and we've got huge pieces of debris

flying right at our building.

[Narrator] This is the age of the extraordinary.

[Hayley] It's like one of those insect-eating plants,

only enormous and white.

[Narrator] Where ingenious engineers have

unleashed unchecked creativity.

Now their secrets are revealed.

As we discover the inside stories of their construction.

This is an incredible feat of planning and engineering.

[Narrator] To try and understand,

"How Did They Build That?"

It takes a lot of money, materials, and brains

to transform the craziest most ambitious designs

into extraordinary buildings.

It also takes time,

sometimes an unbelievable amount of time.

When the world's tallest building,

the 2,700 foot Burj Khalifa in Dubai opened in 2010,

it had been under construction for six years.

But that's nothing compared to this next project.

A Manhattan landmark that's sat unfinished since 1928.

Some 80 years later, it finally emerged.

That's a heck of wait for a new office.

[Narrator] A New York's Manhattan Island,

the home of the high rise.

The constant competition to redefine the skyline with

ever more incredible buildings is reaching dizzying heights.

But in the middle sits what should have been a skyscraper

of a bygone era.

Instead the vision of a newspaper magnate was stopped

at a mere six floors by the Great Depression of the 1930s.

And had been sitting there ever since.

But at a moment in time when it looked as though New York

might never build another of its towers,

a world-famous architect had a radical redesign in mind

and he wouldn't take no for an answer.

[Norman] As I was told, you would never, ever be able

to do that in New York, which of course,

was the greatest incentive to do just that.

[Narrator] It would prove to be a monumental feat of engineering

rising from the ashes of catastrophe.

[Norman] There was open, published speculation,

that was the end of the tall building.

[Narrator] It had become a beacon for strength

and resilience as well as the first of its kind in the city.

New York is skyscraper city, so to pioneer it here,

it's truly amazing.

[Narrator] A radical new skyscraper

rising out of the center of an important old building.

A cutting-edge design borrowed from nature that would push

engineers to their limits.

And require the city to change its way of thinking.

This is the Hearst Tower.

So how did they build it?

New York, in the 1920s

was at the heart of the country's thriving economy.

It was boom time for the city that never sleeps.

People had flooded in from around the world to make

their names and their fortunes.

Land prices had shot through the roof.

And a generation of newly-minted multi-millionaires

decide it's their opportunity to make a mark on the Big Apple.

Harnessing new technology to build bigger and higher

than ever before.

30 years earlier,

Andrew Carnegie finished his landmark Carnegie Hall.

Walter P. Chrysler, the automotive tycoon was

planning on building what would be the world's tallest tower,

the Chrysler Building.

While another gilded-aged billionaire, newspaper man

and politician, William Randolph Hearst

didn't want to be left out.

Widely regarded as the first media mogul.

At its peak, Hearst's newspapers

had a daily circulation of 20 million people.

His life is so successful, he becomes the inspiration

for the lead character for an Orson Wells' film,

Citizen Kane.

But he wanted to make a mark that would stand tall above

the city for 100 years, rising from a corner of midtown.

[Peter] He really envisioned this whole area being

the cultural center of New York

and there was Carnegie Hall a block down.

He had a site next door, which he wanted to build

an opera house.

And he saw his new headquarters in the middle of all of that.

[Narrator] Construction began on his dream tower.

By 1928, the six-story base was complete.

But hit by the Great Depression of the 1930s,

Hearst found himself so deeply in debt that

he had to stop construction and liquidate most of his assets.

Another attempt at reviving his dream of the 1940s

was stopped by the second World War.

Hearst died in 1951, not living to see his towering glory built.

By the end of the century though,

the Hearst organization is in robust health.

And it decides the time is right to bring its businesses together

under one very tall roof.

It's time for Randolph's vision for a Hearst skyscraper

to become a reality.

To pull it off, they turn to one of the world's

most influential architectural practices led by Norman Foster.

We came without any preconceptions

and we challenged a lot of the things that we were told.

[Narrator] Foster has created extraordinary buildings

from scratch like 30 St. Mary Axe in London.

More affectionately known as the gherkin.

But he's also radically reinvented some of the world's

most iconic historic buildings,

including the British Museum in London.

And the roof of the Reichstag in Berlin, Germany.

But Lord Foster's idea for the Hearst Tower

takes reimagining old buildings to a whole new level.

When you're dealing with historic buildings,

there's a lot to consider.

For one, you don't want to damage the existing structure.

The Hearst building is nearly 100 years old.

[Norman] It was apparently always intended to have a tower,

but there were no evidence, no drawings of it.

As I was told,

the one thing you cannot do is take away everything inside.

Now that's called facadism. You would never, ever

be able to do that in New York, which of course,

was the greatest incentive to do just that.

[Narrator] True to form, Lord Foster tears up the rule book.

He's supposed to keep the interior as well as

the exterior intact.

Instead, he plans to scoop out the inside.

Lord Foster plans to remove the roof

and hollow out the insides of the original six-floor building.

All without damaging the historic facade,

so he can create an enormous new atrium.

Steel megacolumns will then rise from the foundations all the way

up to the base of the new 10th floor

where the brand new tower begins.

With beauty and strength, and mind, the diagonal grid

of four-story-long steel trusses will interlock

to create a series of triangles,

the strongest shape which will resist movement

all the way up the 46th floor.

The design is ready to present to their clients,

so Foster and his team travel to New York.

The presentation meeting at the Hearst building

is scheduled for 9:30 AM.

The year is 2001. The date is September the 11th.

I was walking that morning for the meeting.

And I realized as people were gathering and talking

that there was something, something strange going on.

And there were a group of truck drivers talking animatedly

and I was curious and joined them.

Ended up in the cab of a truck listening to the event

unfolding on the radio.

[Narrator] As the Twin Towers collapse in the most deadly

terrorist attack on US soil, the world is changed forever.

It also calls into question the very future of the skyscraper.

At that time there was open, published speculation

that was the end of the tall building.

[music]

[Narrator] Next, will the Hearst Tower ever be finished?

[Narrator] In the weeks after the 911 attacks,

New York City slowly regains its buzz.

Shock has become resilience and resilience is sparking action.

The Hearst Tower remains on the table.

There's a brief moment of pause

for people to process what just happened.

The project went on hold for about a month while Hearst

decided whether or not to proceed with the project.

They realize to not build would signal defeat

and they wanted to show that the city's resilient

and it became one of the first commercial office towers

post 911 to be built in New York City.

[Narrator] With Lord Foster's radical vision signed off,

the engineering team gets to work.

The first challenge is to safely

strip the old building back to facade

while getting it ready for the 40-story tower,

which is about to be built above it.

Because of the enormous weight of the tower,

there's no way it can be supported

by the existing outer walls and original foundations below.

Instead the plan is to create a completely new structure

that doesn't rely on the old building for strength.

Starting with brand new, super strong foundations.

Luckily, there is a reason Manhattan is

home of the skyscraper.

Manhattan's well-known for its granite base and you don't have

to go down far to hit bedrock unlike other cities.

And there was no exception here as well.

[Narrator] Constructing solid foundations is often one

of the unknown costs in the construction world.

But here, they are in luck.

With shallow foundations you don't have to dig as deep,

so it's usually easier to construct and it costs less.

[Peter] The original building had a basement and

not far from the basement is pretty solid bedrock,

so we didn't have to excavate too much.

[Narrator] The engineers start work on the megacolumns,

attaching them to the newly constructed foundation

sunk into the bedrock below.

These huge structural legs will literally hold the tower

above the old Hearst building.

We wanted to limit the amount of columns that would touch the

ground because that meant a lot of excavation and demolition.

[Narrator] The problem facing the engineers

is how to do this while protecting the old building.

[Hayley] In a traditional building,

the floors inside brace the walls

interconnecting everything. This creates a strong box.

Take those away and everything becomes weak and unstable.

[Narrator] Lord Foster's design requires taking out all the old

internal walls and floors from the original six-story building

to create a show-stopping atrium underneath the new tower.

Ahmad Rahimian is the engineer charged with doing this

without it all falling down.

[Ahmad] In order to provide lateral bracing,

in absence of the original floors for the facade,

we devised a new set of framing,

a grid system behind the existing facade.

[Hayley] Building a super strong skeleton inside the old walls

and tying these into the new megacolumns

means you can safely take away the floors.

[Peter] Once we inserted the columns and the tie beams,

they were ready to be cleared out of all the supporting slabs.

[Narrator] The construction crews

demolish the interior floors

creating a giant hole they soon hope becomes a stunning atrium.

The megacolumns extend another four floors above

to the 10th floor,

the structural heart of the new tower.

The 10th floor is our major support floor.

Its job is to transfer the load from the diagrid system above

into the perimeter megacolumns in the base below.

All whilst incorporating the visual trick of appearing

to float above the original building.

[Narrator] Now the engineers face their biggest challenge,

constructing the new glass tower that's going to

sit over the old building.

Lord Foster goes for a structure that borrows its design

from the natural world.

If you want to track that down through structures in nature,

spider's webs, whatever.

You'll see the principle of triangulation.

[Narrator] It's called a diagrid.

An exoskeleton of steel that takes the load

instead of the internal columns found in most buildings.

So in the event of any catastrophe

where you take away part of that structure,

there are more parts that the load can take.

So it's more resilient. It's stronger.

[Hayley] It basically works like a web of triangles

all pushing together at their points.

And pushing against each other,

they essentially support each other.

The diagrid essentially became a solution to the problem

with the building being destabilized.

But it also turned out, there are many other benefits.

Less materials are used and it looks pretty cool, too.

[Norman] The triangulated structure in Hearst

uses 20% less steel,

2,000 tons for a structure, which is actually more rigid.

[Narrator] The engineers and construction crews

get to work erecting the tower.

New York has never seen anything like it.

[Corina] New York is skyscraper city,

yet the diagrid system had never been used in one.

So to pioneer it here, it's truly amazing.

[Narrator] The tower grows and the diagrid structure

is tied into the core of the building

making it even stronger.

[Ahmad] There is a symbiotic relationship

between the external diagrid with that internal-core

structure with both supporting each other in an elegant way.

[Peter] It's not just vertical gravity that we're dealing with.

We also have to work with lateral movement

because of wind and seismic, so the diagrid takes all those

complicated forces, interconnects amongst itself

and then ties it back at every floor.

[Narrator] In most skyscrapers, the ironwork that gives strength

is hidden away in the structure, so none of it can be seen.

In the Hearst Tower,

Lord Foster decides to celebrate the framework instead.

The structure is very much part and parcel of the architecture,

which is holding it aloft.

To clad that in stainless steel with the sharp angles

means that it's forever changing its appearance

depending on the weather.

Subliminally that choice of polished stainless steel

is evocative of other buildings,

which are symbolic like the Chrysler Tower,

which is one of my personal favorites.

[Narrator] In 2005,

the Hearst Tower is finally complete

reenergizing and redefining the beating heart

of the Hearst Corporation.

[Norman] I go back to Hearst.

New York is the city of skyscrapers.

Amazing we've got a skyscraper in New York.

[Peter] The joy of not only designing the building,

but then to have our office in the building

is that you're able to see how the people use it.

Basically, this has been our home for the past 15 years.

[Narrator] The Hearst Tower is the perfect marriage

of the old and the new.

Foster's rebellious act of scooping out the building's

inside has created an enormous, exciting and welcoming space.

While outside, New York's first diagrid skyscraper

reinvigorates one of the city's historic landmarks,

redefining what's possible.

Visionary design and groundbreaking engineering

puts the Hearst Tower on the map after 80 years of waiting.

[music]

How do you like hanging out in an airport?

No? Me neither.

We got to airports only to get somewhere else.

The musty air, the impossible to find bathrooms

and a cup of coffee the price of molten gold,

no thank you.

But in Singapore, they do things differently.

Forget squeaky baggage carousels and security lines

longer than your holiday and think tropical rainforest

with infinity waterfall falling from the sky.

At last, an airport that is a destination itself.

As for the overpriced coffee,

yeah, I'm afraid that's just an airport law.

[Narrator] With a population of close to six million,

Singapore is a small country with a big economy

and a determination to create a world-class impression.

So in 2013,

as the city state is growing in economic power and stature,

it wants the new airport to reflect its vision.

Somewhere that will blow away anyone who sees it.

[Cristobal] There is no other airport terminal building

like this anywhere.

[Narrator] It has the world's largest gridshell roof

with a huge cylinder of water pouring through it.

Becoming the tallest indoor waterfall on the planet.

This is Jewel Changi in Singapore.

The engineers that made this happen

are pure magicians, period.

[Narrator] It's a place where lucky passengers wander

through a huge indoor garden that's among, you guessed it,

the largest on the planet.

Between them, architects and engineers

created a 10-story tall, 1,460,000 square foot

man-made paradise.

And all of this happened while one of the world's busiest

airports stayed open and a train ran right through the site.

Next find out how they built it.

[Narrator] It's 2012.

Singapore Airport is handling around

50 million passengers a year.

And come second in the world airport awards.

Good, but not good enough.

In a country that wants its already successful economy

to really take off.

Hoping it will increase capacity and attract new business,

they decide to create a brand new departure's hub

and invite some of the world's leading architects

to come up with a startling design.

Boston-based Safdie architects are invited to bid for the job.

The bid document that we received requested an expansion

of the retail facilities at Changi Airport,

but also a major attraction of unknown design and program.

And so our task was to conceive of some kind of

unknown attraction.

Together, it is something that would be

a destination for Singaporeans and visitors alike.

[Narrator] The team that wins the bid will get a huge prize,

a project with a budget of 1.6 billion dollars.

Even though airport structures are big,

with a budget of over a billion bucks,

you can make something really special.

And that's exactly what Singapore Airport wanted to do.

[Narrator] Home to some of the world's most

groundbreaking pieces of architecture

like the Sky Gardens and Gardens By The Bay,

the bar is already set pretty high in Singapore.

But it also gives the Safdie team inspiration.

[Jaron] Singapore's a place that is the Garden City.

And we said, well, the garden is the attraction.

A garden is a timeless destination

that would draw people from near and far.

Something so spectacular and the scale of which

has never been done before.

[Narrator] They come up with a truly extraordinary design

for the new airport.

Part shopping mall, part urban forest.

They will create a valley that climbs up steeply

over five floors

hiding over 300 places to eat and shop.

All of this will be covered by over 9,000 panels of glass

with practically no support from underneath.

In the center, there will an oculus or hole to the outside.

Through it, every minute,

10,000 gallons of water will fall into a pool 130 feet below.

The experience of being within this transport-hub wonderland

is expected to be completely unique.

But before anyone can enjoy it, engineers have to figure out

how on earth they're going to build it.

Starting with the enormous roof, all 325,000 square feet of it.

The first time I saw the design from the Safdies, I was like,

wow, what a great space.

They, of course, they had drawn things without

having a very good idea of the engineering behind it,

but I sensed that it had a logic that I could work with.

[Jaron] The test was how do you make it as light

and as elegant as possible?

We were trying to create as visible impression of the sky

as possible.

[Narrator] The solution is to create a super-strong structure

known as a gridshell.

Gridshells are awesome. They're strong and light,

which means you can create huge spans of unsupported roof area.

But ideally, they need to be symmetrical.

This means that the load can be evenly distributed.

And it's also just a lot easier to build.

[Narrator] Here though, it can't be.

A sky train runs through the middle of the site,

which would put it right underneath thousands of tons

of water cascading down onto the tracks.

We couldn't have the water over the airport train.

We couldn't shift the airport train,

but we had to shift the waterfall over to the side.

[Jaron] Of course, it would have been interesting

to go through the waterfall on the train,

but the engineers didn't really like that.

[Narrator] Moving the waterfall from the center of the roof

has big consequences.

It means that each panel and every connection is

different from the next.

[Cristobal] You have thousands of different elements

and only one element belongs in one place.

They're not like, interchangeable.

And so basically what you're gonna do is you're gonna

manufacture all these pieces that are all different,

all customized using computers and milling machines.

We digitally milled these steel surfaces in Germany

and places like Malaysia.

And they were all shipped to site in containers

and then bolted in place in the exact position

that they needed to be.

[Cristobal] I think this building showcases

what you can do now with computer-aided design

because it allows you to sort of mass customize something.

[Narrator] Next, 9,304 unique triangular panes of glass

are fitted to complete the roof.

Although the dome weighs 4,000 tons,

it's so strong and has been engineered so precisely

that it needs minimal support inside.

[Cristobal] There's 14 columns. We call them tree columns that

support the gridshell between the perimeter and the waterfall.

[Narrator] Incredibly, all through construction

the airport keeps functioning as normal.

Even the sky train runs through the site

shielded from potential damage

by a temporary protective tunnel.

The next challenge for the engineers is creating a system

for getting 10,000 gallons of water up onto the roof

to feed the waterfall

without ruining the look of the beautiful design.

[Cristobal] We are doing something that we hadn't

done before and we're going to make something beautiful,

but you know, there's always a little level of fear um,

that we have to control.

[Narrator] Although the team had created waterfalls

inside buildings before,

they'd not done anything on this scale.

In fact, no one had.

[Jaron] It wasn't our first rodeo in a sense

in terms of creating a waterfall inside a building,

but in order to deliver this,

we had to do two and a half years of research.

We built full-scale mockups.

[Narrator] The extensive testing yields a system

that is efficient, ecological and invisible to the public.

You want to do it in a way you can't really tell

where the water is coming from.

[Narrator] And that's exactly what they achieve.

The water starts its journey in a 115,000 gallon holding tank

built in the basement.

From thre it's pumped in eight pipes up four floors

to ground level.

This is where the roof becomes visible to anyone inside.

And the water needs to be moved in secret.

[Cristobal] So the pipes that feed the waterfall

come out at level five

and they actually go through the fins

that are on the outside of the gridshell.

And there the water all collects

and then it all gets directed downward.

[Narrator] With the water on the roof,

the next challenge is how to deal with the deafening noise

created by five tons of water per minute

crashing down into the pool below.

But the specialist water featured team

comes up with a slick solution to turn the volume down.

They install a huge dished acrylic funnel,

which reduces impact,

so the water slides quietly down the four floors below.

This also creates an incredible visual feature to see

in the basement shopping mall below.

And in addition, the waterfall creates

air currents that cool the building and cool the garden,

and help temper the air for the people

who are enjoying the gardens below.

[Narrator] The next challenge is working out how to create

a healthy 5.6 acres of forest garden in the cooled valley.

Many of Singapore's tropical, indigenous plants

will struggle to survive.

So the five stories of steep terraces are planted

with 120 species normally found in high-altitude forests

around the world.

The team have to plant 60,000 shrubs, ferns and flowers.

Plus 3,000 mature trees,

including 40-foot palms so heavy,

they have to be winched into position.

And a 120-year-old tree from Spain.

It's taken six years.

It cost 1.25 billion dollars to complete.

The question now

is will anyone like it?

[Narrator] Most of the world's airports

are 21st century bus stations, drab and gray,

shaped more by the mechanics of transit

than the beauty of design.

But on Easter Sunday in 2019,

the boldest most spectacular airport terminal in the world

opens its doors.

And 600,000 people rush in to see it,

10% of Singapore's entire population.

[Jaron] It was almost like a festival had arrived at Jewel.

There were so many smiling faces upon the opening of this project

and it was just heart-warming.

It was a proud moment for the whole team.

[Narrator] Underneath seven acres of steel

and glass gridshell,

visitors can enjoy sky nets, crystal clouds and mazes.

Or they can brave the 165-foot long,

glass-bottomed canopy bridge suspended 75 feet in the air.

While below it,

travelers enjoy the spray wafting from the rain vortex.

When you see people arriving with their suitcases,

they're just kinda, they're like, a little bit dumbstruck.

They can hear the waterfall.

They can feel the wetness from the waterfall.

They can see the green.

And it think it's just like, kind of overwhelming.

It's a very inspiring space.

[Narrator] And nighttime brings an even more

show-stopping spectacle.

With light projections dancing off the cascade.

This airport is no longer a way station to other destinations.

It is a destination itself.

No surprise that Jewel Changi surpassed its annual target

of 50 million visitors just six months after opening.

I don't know any other airport where people say,

I want to have a stopover, because that way I can see it.

In that sense, I think it really put Changi Airport on the map.

[Narrator] In 2019 and 2020,

Singapore Airport is ranked the world's best.

It also gains an unbeatable platinum award

for sustainability.

[Jaron] I don't think I'm alone in saying that Jewel was one

of the most complex projects that I've ever worked on.

And I'm very proud that we were able to deliver what we promised

if not more than what we promised.

[music]

Now if you were asked to design a museum

inspired by Salvador Dali,

one of the greatest surrealist artists who ever lived,

how tempting would it be to shape it

like a huge melting clock?

Or like a lobster telephone?

That would be crazy.

Almost as crazy as say,

building a museum around an endless helical staircase.

No one would ever be crazy enough to do that, right?

Wrong.

[Narrator] St. Petersburg, Florida.

Locals call it St. Pete.

Tourists attracted by an average of 361 sunny days per year,

call it Sunshine City.

Home to around 270,000 people who came for that sun and water.

St. Pete has another attraction

that might broaden the city's appeal.

Because it's also home to one of only two major museums in the

world dedicated to the works of Spanish artist, Salvador Dali.

A building that's almost as strange and arresting

as the paintings that hang inside.

The result is a mind-bending building to look at.

[Narrator] A building as tough as it is good looking.

It can stand up to a two by four being

shot out of a cannon at it.

[Narrator] It's protected from the worst of Florida's weather.

This is the Dali Museum, St. Petersburg.

So how did they build it?

St. Petersburg may not immediately seem

the most obvious place to find a collection of over 2,400 pieces

by the Spanish artist, Salvador Dali.

A man whose paintings sell for tens of millions of dollars.

The story behind the museum and the artwork in it

begins with a love affair started some 80 years ago.

This collection,

which is the preeminent collection of Dali in the world

was formed by Reynolds and Eleanor Morse.

They had collected Dali from the first days of

their romantic engagement.

They actually bought each other a Dali painting

as a wedding present.

[Narrator] That was in 1942.

And over the next 25 years, they added to their collection

becoming both Dali's patrons and friends.

In 1971, they decided to open their first Dali museum

in Cleveland, Ohio.

With Dali attending the opening in person.

Ten years later, they decided to move the collection.

And eventually, they found a location in St. Petersburg.

The museum opened in 1981 in a downtown marine warehouse.

And here it stayed for another 28 years.

But there was a problem.

Florida's six-month hurricane season wreaks yearly destruction

up and down the coast.

And every time a major storm threatened the area,

the incredible collection of paintings and rare books

worth millions of dollars

had to be moved in case the worst was to happen.

In 2008, the museum decides it wants to redesign the building.

To do it, they bring in Yann Weymouth.

Who'd been involved in creating the glass pyramid

at the Louvre in Paris.

Yann has bigger and bolder ideas than simply

redesigning the existing space.

[Yann] The museum was right on the water

and it was very vulnerable to potential storms.

The first goal was protect it

from any potential climate events.

The second goal was, oh, and by the way,

we would like the museum to be unlike any museum

we've ever seen, and iconic.

[Narrator] Having convinced the foundation that this

irreplaceable collection needs a completely new building,

Yann gets to work designing somewhere strong enough

to protect it from Florida's most violent hurricanes.

[Ellie] We've got 150-mph winds.

We've got storm surges. We've got floods.

And we've got huge pieces of debris

flying right at our building.

Protect the collection is making this place a fort.

[Narrator] At the heart of the design

is a box that will be so strong

that it will fend off anything the weather throws at it.

The walls are 18-inches thick.

And they are laced with

hundreds of kilometers of steel bars.

[Narrator] The engineer charged with building

this impregnable gallery is Scott Martin.

[Scott] We wanted to make the building to protect the artwork.

That's what really drove me to and got me excited

to protect the artwork no matter what elements

mother nature had to throw at it.

[Narrator] Although concrete and steel is a tried and tested

construction method,

building in Sunshine City

gave the engineering team its first headache.

[Hayley] When poured in hot weather, concrete sets faster,

so you must work quicker.

Moisture evaporation is accelerated making cracking

more likely reducing the overall strength of the concrete.

[music]

[Narrator] Next,

can they pour it fast enough?

[Narrator] In Florida,

the new Salvador Dali Museum is under construction.

And the massive job of pouring the concrete is underway.

Because so much concrete would be visible

in the finished building,

the design spec also requires minimal joints.

The engineer's solution to both challenges

is to use a system of form work or molds,

which they then fill with huge batches of concrete.

But that creates another problem, wood,

the material traditionally used to build the molds

isn't going to be up to the job.

[Scott] There's a lot of outward forces exerted on the form work,

so they use steel form work here and with strong ties going

between the two, so when they pour the concrete inside of it

and the concrete wanted to force the forms apart,

the forms kept it together and were able to

because they were made out of steel.

[Narrator] It takes seven months and 20,000 tons of concrete,

but in October 2009, the cube is complete.

That was the first part of the concept, strong box.

The problem with a strong box is the gold of the United States

is kept in Fort Knox in Texas.

And fortresses are not terribly inviting to come in.

A challenge that engineers and architects face

is that balance between form and function.

The easiest way to protect the art would have been to lock it

in a big concrete box, but where's the fun in that?

This building is not only about keeping something safe,

it's also about showing it off.

How do you make a museum that people will want to be in

and how do you make that museum not claustrophobic?

Well, that's very simple.

You give them light. You give them space.

You give it volume.

The box needs to be somewhat disrupted by something in glass.

[Narrator] Yann's solution is to leave open part of the

concrete box in order to bring light into the huge atrium

and the galleries.

They'll then create a futuristic glass dome worthy of Dali

nicknamed The Enigma.

It will be made up of 1,062 triangular panes of glass.

Although the idea comes from Yann and the team,

the final design isn't down to any human.

This structure is possible

because of computer-aided design.

By using computer software, we can create

really complex designs allowing us to push the limits

like never before.

[Narrator] Despite being largely made from glass,

Enigma has to be super tough.

Fabricated in triangular panes, the strongest shape.

It is also made from reinforced structural glass.

Then it needs testing to make sure it is tough enough.

Because we're in a large missile-impact region

or a windborne debris region,

um, and that's anywhere in Florida where the winds

can go over 140 mph.

Any kind of glass needs to be impact resistant,

which means it can stand up to a two by four

being shot out of a cannon at it.

So all the glass panels have been designed and tested

at a wind tunnel test in Miami.

They've got a two by four cannon.

They shoot it at glass panels to make sure

it can stand up to large missile impact tests.

[Narrator] With the artwork safe

and the outside of the building solid,

Yann has one very large surrealist twist in mind

for the center of the museum.

Something that would have made Dali himself smile.

[Yann] We have three high-speed, very efficient, energy-conscious

elevators to take people up,

but how do you signal to people that there's a way up?

A spiral staircase seemed a natural.

Dali loved spirals.

He loved DNA. It's a structural tour de force.

[Narrator] The enormous spiral staircase is to be made entirely

out of steel and concrete

touching the building at two points.

The engineers pour the concrete in eight-foot sections

and have to support it as they go

because it won't be able to stand by itself

until it's finished.

And even then, only if they get it right.

[Scott] We'd never done a stair like this before

that was free standing like this.

So when using shoring on something like this

and the concrete has to stand on its own.

[Narrator] The moment of truth comes.

And the engineers remove the form work to see

if their calculations are correct.

One mistake and they will be left with a pile of rubble.

[Scott] It's always a little nerve-racking and um, maybe

get a couple of sleepless nights out of it, but at the end it all

came out like we designed it to.

[Narrator] It may have taken three years in the making,

10,000 yards of concrete,

220 miles of rebar,

and 1,062 triangles of glass,

but in 2011, the Dali Museum is finally complete

and ready to throw open its doors to the public.

[Yann] They were astonished.

I'm sure some of them thought it was strange.

There's a sense of life to it.

[Scott] I think Dali would have been impressed.

It's something that's outside the box.

It's surreal, that's unique, that's completely atypical

to anything else around here or in the country.

Uh, I think he would have been proud of,

of the building that we built.

[Narrator] Designed to survive the worst hurricanes imaginable,

the Dali Museum will continue

to keep this quiet corner of Florida,

weird, for years to come.