Original subtitles

[Male narrator] How do you build a 34-story tower block

that won't cast a shadow over its neighbours?

My first reaction to seeing this was, "Wow".

[Narrator] What happens when a national opera house is built

into the sea alongside a major shipping lane?

Cruise ships, cargo vessels, and ferries passing right by.

The last thing you want is one traveling up

and interrupting a performance of Madame Butterfly.

[Narrator] And what do you call a building that incorporates

an aquarium, a planetarium, and a four-story tropical rainforest

under one roof?

If you think of a museum as a place full of old dead things,

then this place will blow your mind.

[music]

[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?"

For our first architectural marvel, we head down under

to a world-beating tower that raises many questions.

For example, how do you make a vast living garden grow

on the side of a huge building?

And what exactly is a heliostat that uses over

300 intelligent mirrors to banish shadows?

This Sydney landmark may raise a lot of questions,

but as you'll see, it has all the answers.

[music]

[Narrator] The state of New South Wales

in southeastern Australia is famed

for its endless golden beaches,

2,500 hours of sunshine every year,

and one very iconic opera house.

When it comes to architecture, the residents of the capital,

Sydney, are used to bold design.

But in the city centre, planners faced a problem:

how to build a colossal new tower block without blocking out

the sun from the surrounding historic neighbourhood.

[Corina] Living in a city apartment,

high up, means lots of light,

great views for you.

But those down below are living in your shadow.

[Narrator] This is what happened when architects pushed engineers

to their limits...

Wanting to bring the sun back into the inner city

by hanging it from the top of a tower block.

My first reaction to seeing it was, "Wow."

I mean, out of this world and something that's never been seen

before in Sydney.

Pretty much at every turn of the design development,

there was somebody saying, "Are we really gonna do this?"

[Narrator] Comprising of an intelligent 110-ton mirror,

flanked by the world's then-tallest

120,000-square-foot living wall, and in the part of the city

near impossible to build on, this is One Central Park,

Sydney, Australia.

So, how did they build it?

Tucked away just two miles from Sydney's iconic harbour

is the gentrified suburb of Chippendale,

a mix of 19th-century terraced housing, and for 170 years,

one of Australia's biggest and oldest breweries.

When the brewery closes in 2005, it releases to market

a large plot of inner-city land ripe for development.

[Mick] The site was an old brewery.

It was the old Carlton United Brewery,

and it was two kilometres from the central business district

of Sydney and a six-hectare site.

There was a lot of community concern about the challenges

of creating increased urban density and still maintaining

liveable environments for people.

[Narrator] The plan is to develop the six-hectare site

as a mixed residential, office, and retail precinct

with two parks.

To make it financially viable, developers need to build

two apartment towers.

But planning regulations here restrict them to a maximum

of 10 stories, to limit the shade it creates.

The designers propose building taller towers,

but away from the neighbours to the north of the site.

That creates another problem.

Normally, you would open up your development

to the northern sunlight, in a temperate climate like Sydney.

So we tried to come up with a creative way

to celebrate the sunlight that

really counteracted the fact

that we put all the massing of these buildings to the north.

[Narrator] Their proposed solution is a radical

reimagining of an ancient technology called a heliostat

on a scale never tried before.

A heliostat is actually a really old piece of technology

that uses carefully positioned mirrors to bounce light

into shaded areas.

Now, in ancient Egypt, they used to use slaves

to hold these mirrors, but luckily nowadays we have

computer programs linked to motors that can control them.

[Narrator] They're also determined to make sure

this development has some seriously green credentials.

[Corina] The problem with building

high-density residential blocks in inner cities

is how to avoid taking up valuable green space.

One answer is to make that green space vertical.

[Narrator] They come up with a pioneering design

that they hope will overcome the problem

of shading their neighbours while still making the scheme

financially viable.

At its heart will be two towers.

The west tower will be 17 floors, while the east

will be 34-stories high, casting a large shadow over the park.

But on its 29th floor, this tower will have a huge

cantilevered sky garden onto which a giant array of mirrors

will be attached to bounce sunlight down to the ground,

bringing sunshine into the shade.

Finally, nearly 100,000 plants will be added to the side

of the buildings, creating over a million square feet

of vertical hanging gardens to help integrate the towers

effortlessly into the surroundings.

In 2010, work begins on the towers,

and it's straightforward enough.

But then, engineers need to find a way to attach a 110-ton

bank of mirrors 148 feet from the building, 300 feet up,

in mid air.

They planned to do so using a tried-and-tested engineering

method known as a cantilever.

The giant cantilever on this building not only defies gravity

but it hovers over prime residential real estate below.

[Narrator] This allows the overhanging heliostat

to only be supported at one end, giving the appearance

that it is floating on air.

It relies on a series of huge steel trusses.

[Mike] There's a lot of engineering solutions

in designing the trusses to support the cantilever.

And we're talking truss panels that are 75-ton to 90-ton

in weight, lifting those up.

[Narrator] With the huge steel trusses craned up

to the 29th floor, then fixed to four rods on the opposite side

of the building, the team turns its attention to the heliostat.

Helios is the Greek god of the sun and status means

a particular position at a give moment in time.

So a heliostat is a mirror device that can compensate

for the sun's movement across the sky and make it static.

[Narrator] Modern large-scale heliostats are used

the world over to generate renewable energy.

Hundreds of static mirrors are arranged in a circle

so that at least one of them will catch the sun

throughout the day and bounce it to a central point.

In Sydney, they don't have the space for all those mirrors.

And they need to work out how to bounce sunlight

around the building and light up the park on the other side.

It took a while to understand how we're gonna deliver this.

When you saw the sketches of the design, I thought,

"Who does this work?

"There's not someone you can go around the corner and say

"can you do this?" It's a very difficult task.

[Narrator] Designers come up with a groundbreaking solution.

By using mirrors on the roof of the west tower to bounce the sun

up to more mirrors on the overhang of the east tower,

they can reflect light into the shaded areas

around the buildings.

But there isn't space on the west tower for enough

static mirrors to catch the sun as it moves through the day.

Their simple but ingenious solution is to motorize the ones

they've got, and link them to a computer-controlled program

to track the sun.

The computer on this heliostat is ingenious.

Not only does it calculate the position of the mirrors

relative to the sun at any time on any day,

it then moves and angles them to continually track the sun,

bouncing its power up into the static mirror array,

which then reflects the light down to the shaded areas below.

[Narrator] The result solves the problem of creating light

where there is shade.

But it creates another one in its wake...

How do you lift and suspend a 110-ton structure

with 320 mirrors?

We had to think about how could we build the most

of this structure on the ground, and then lift it

into its final position in pre-assembled elements.

The main challenge in being able to do that

is when you preassemble the building elements,

they become really heavy.

[Narrator] The solution is one of the world's largest

tower cranes called Tinkerbell, which they transport

thousands of miles from a mine in western Australia.

It costs six times more than a normal crane

and can cope with the enormous weight

of the pre-assembled framework.

But this creates yet another problem...

Colossal cranes and dense downtowns don't mix well.

One of the other major challenges was the fact

that there's a major arterial road called Broadway

immediately below the site,

which is taking thousands of cars in each direction

while we're undertaking this task.

We definitely couldn't close off the road

to undertake this activity.

We had to develop a lifting plan that would consider

the conditions that would be most appropriate to undertake

such a high-risk lift.

[music]

[Narrator] Next, can the team pull it off?

[Narrator] In Sydney, Australia, in the early hours

of the morning, work starts on getting the steel frame

for the mirrors into the air.

To do it, they brought in Tinkerbell, one of the world's

tallest tower cranes.

Now all they can do is hope things go to plan.

One of our key enemies when we're working at height

is wind, so you know, we had to make sure that we were,

you know, carrying out the task in the appropriate conditions.

[Narrator] Any sudden gusts while lifting the frame

into the air will be disastrous.

But after months of meticulous planning and organization,

the structure is finally attached to the building.

Incredibly, it's done in under two hours.

And there was a sense of relief when the load was lifted

in position and eventually bolted onto the building

and released from the hook of the tower crane.

I think a few of the boys definitely went

and had a beer after that one.

[Narrator] With the framework in place,

the 320 mirrors are hung, and the team turns its attention

to maximizing the building's green credentials.

The plan is to build the world's then-largest living wall.

[Jock] Nothing like this project had ever been done anywhere

in the world.

The green wall's on here by a French guy, Patrick Blanc.

He's very well known for his green walls.

He was the pioneer of green walls in the world.

He has green hair, he has green fingernails.

And he doesn't drink water, he only drinks champagne

'cause water's for the plants, is what we were told.

[Narrator] Creating the largest vertical garden the world

has ever seen is a serious challenge.

[Ellie] A living wall might seem like a really simple idea,

but if you think about what it takes to just plant up

a simple garden or yard, and now you do that on a vertical plane

hundreds of feet up in the air, it gets a lot more complicated.

[Narrator] The engineers need a framework big enough

to house the plants, and strong enough to remain upright.

The weight of the planter boxes was a key consideration

because they had soil for the plants to grow in.

When it was wet, that added weight.

So we had to engineer these boxes to attach to the building

and cope with the loads.

[Narrator] To pull it off, the team has to create

a unique system.

[Adam] We undertook a number of prototypes to try and develop

our solution, and we finally arrived at a rotomold...

A polyethylene tub, if you like.

This tub had to be overclad with the building fabric

so that these planter boxes looked integral as part

of the building.

[Narrator] The planting takes 2,000 man hours and injects

over a million square feet of greenery

into the urban landscape.

[Jock] There is 1,120 square metres of green walls,

and it's 5.5 kilometres of planter boxes

if you put them end to end.

So overall, I think there's about 98,000 plants

on the project.

[Narrator] Even the watering system that feeds over 3 miles

of planter boxes is sustainable.

All of the water is actually from treated sewage.

They actually have blackwater treatment plant on site

that manages the sewage, turns it into A-grade drinking water,

which we then get to use on the project.

So a very water-efficient project at the same time.

[music]

[Narrator] Finally, in 2013,

after 6 years of planning and building,

One Central Park is finished

and opens to residents, workers and members of the public.

So it gained two World Awards for this site

that we started off just wanting to do a good job.

Well, it was recognised as being a good job.

[Mike] A couple of the people

in the department's planning department

nicknamed it the diving board, but there's absolutely no doubt

that people will recognise the green building

with the reflectors on the giant cantilever,

and everybody knows the building you're talking about.

[Narrator] Combined with sustainable architecture,

it showcases how living walls can bring greenery and life

to the urban jungle, both inside and out.

[Man] I've got the hanging gardens

just right outside my balcony.

It makes me feel as though I have a garden apartment.

Every now and then, I do drive past this building

or drive on a road where I can

see the building in the distance.

And you know, I always look at it with great pride

and satisfaction, knowing that I was able to play a part

in, you know, creating this great building.

[Narrator] One Central Park not only changes the Sydney skyline,

it alters the perception of what urban living can be...

Exceeding the expectations of the people of the city

and flying the flag for

world class engineering and design.

[music]

From Down Under to the top of the world

and the Norwegian capital of Oslo.

Now, when you're asked to design a monumental new home

for your nation's opera and ballet productions,

there are a few things you must obviously include.

An excellent stage for performers,

a comfortable auditorium for visitors, and of course,

an enormous under-the-sea barrier due to

the unacceptably high risk of a ship colliding

with the building. I made that last one up, right?

Nope.

Titanic the opera anyone?

[Narrator] The Scandinavian country of Norway is renowned

for its stunning 35,000 miles of coastline

and the 1,700 fjords, or flooded sea valleys,

carved along it.

These breathtaking natural wonders attract tourists

by the millions.

Then in 1999, one fjord became the setting and inspiration

for an attraction of its own... One of the country's

most ambitious cultural buildings.

It's this giant marble wedge that looks like it's slipping

into the fjord.

[Narrator] Built both on land and under water,

this extraordinary feat of design and engineering

is supported by 17 miles of steel piling, driven deep

into the icy North Sea.

It looks like they've carved up a glacier or an iceberg.

[Narrator] Featuring a 32,000-square-foot

wave-shaped wall, crafted from white American oak,

and finished off with a rooftop piazza made from 35,000

hand-cut slabs of soft white Italian Carrera marble,

this is Oslo Opera House, a worthy home

for Norway's National Opera and Ballet.

So, how did they build it?

[Narrator] The 60-mile-long Oslo fjord on Norway's

southeastern coast is breathtakingly beautiful.

And it's clearly a massive challenge

to create anything as stunning

as Mother Nature has done herself.

But at the end of the 20th century,

the Norwegian government sets itself that challenge.

It had a bold new vision for Oslo's industrial harbour front.

This includes their first national opera house.

The opera house was announced as a big international architecture

competition, there were about 320 different projects

being delivered.

It was a jury working for a year, and finally,

at the end of this, they chose our project.

[Narrator] The winning design is by Norwegian firm Snohetta,

renowned for their futuristic Le Monde Group HQ in Paris,

and another underwater building, the radical Under Restaurant,

built in the North Sea.

They approach the design of the opera house

with a bold vision.

[Kjetil] The building became this negotiator between the sky

and the water.

So it wasn't a building per se. It was a public plaza

on top of the opera functions.

[Narrator] The idea translates into a vision

that looks great in blueprints, but gives the engineers

some sleepless nights.

One half of the building will sit on an area of unstable

contaminated land at the harbour's edge.

The other half will dive in and under the sea.

Covering an area equivalent to four football fields,

the plan is for the opera house to be divided

into three main zones over four floors.

Outside, the plaza, which includes the roof,

will be laid with 215,000 square feet

of Italian white marble, all accessible to the public.

The rear of the building will sink 53 feet below sea level

and house the stages and an incredible 1,100 rooms,

including workshops and rehearsal spaces.

Finally, a huge wall of white American oak, called the wave,

will divide the land from the sea, and the public spaces

from the 1,400-seat auditorium.

But before the first foundation stone can be laid,

the team has to deal with an ancient problem.

Norway dominated Europe's timber trade.

Sawmills lined the country's rivers and waterways,

including the Akerselva, which runs into the harbour.

For centuries it carried sawdust and industrial pollution

with it.

[Corina] First, they're building below the waterline,

in water that will freeze in winter.

Then they're dealing with heavily polluted

centuries-old dock waste.

And then they're drilling down to the bedrock.

It's not an ideal location.

[Kjell] So that was a big challenge, to build something

out in this area, with the sawdust conditions

and the very soft clay conditions

and the large depth, the bedrock.

[Narrator] Rather than trying to build under water

on the soft sea bed, the team decides to create a cofferdam,

a circular perimeter fence using 129,000 square feet

of steel sheet pile, before pumping the water out.

Build a structure in water is always challenging.

But when that water freezes every single winter,

the structure needs to be not only watertight,

but incredible strong.

[Kjell] The cylindrical shape is essential here.

The cylinder is, in its shape,

able to take up much larger pressures from the outside

than a box, because the forces go in very nicely

into the cylinder walls.

And this is why we make lots of structures with cylinders.

Why are the big platforms he put in the North Sea cylinders

and not the not square boxes?

It's because the cylinder has this great capacity

to take external forces.

[Narrator] With the cofferdam in place and the water pumped out,

the excavation begins to create a basement big enough

to house 16 elevators, a rotating stage,

two side stages, and a background stage,

53 feet below sea level.

As they dig down, the circle of sheet pile needs a series

of concrete ring beams to hold it all in place.

[Kjell] When we cast a concrete ring beam, you create a support

of the sheet pile that allows it to perform as it should.

Then we excavated down to a certain level,

cast the concrete ring beam.

Excavated further down, cast a new concrete ring beam,

until the final depth 16 meters below sea level

[Narrator] Although they've overcome the physics of water

and created a dry space to work on the foundations,

completing those isn't going to be easy either.

The bedrock is up to 180 feet down.

We have, if I recall correctly, 700 piles.

And the total pilings of 28 kilometres.

So it's quite a bit of steel piles under this building, yes.

[Narrator] Creating firm foundations takes

an extraordinary 17 miles of piling.

But the opera house's location still has another headache

to overcome.

What is the probability that some of the large ferries

that use this part of the harbour area

could have loss of control?

[Narrator] A large part of the opera house will be hidden

underwater with two ferry terminals nearby.

Experts decide the risk of a collision is unacceptably high.

[music]

[Narrator] Next, can engineers make it safe?

[Narrator] Every year, cruise ships make around

35,000 in-port manoeuvres, almost all without incident.

But when they do go wrong, the consequences can be disastrous.

A collision with the Oslo Opera House could be catastrophic.

You've got cruise ships, cargo vessels, and ferries passing

right by.

The last thing you want is one traveling up that slope

and interrupting a performance of Madame Butterfly.

[Narrator] Planners decide the solution is to build something

called a berm.

[Hayley] A berm is a manmade bank of earth and rocks.

On land, it could be used structurally to hold back

a slope or to create a barrier.

Here though, it's got to hold back an entire ship.

[Kjell] The only solution was to build an artificial barrier

into the sea in front of the opera.

And this, this barrier is made of rockfill.

[Narrator] Creating an underwater berm 230 feet wide

and 27 feet high is an enormous job.

This is a ship and here is a barrier.

And the ship comes in here, and it hits the barrier,

and it will start to lift out of the sea, the front.

It's like a collision with a rock, right?

Where it starts raising up.

When you start to lift the ship out of the sea, you use energy.

So this lifting energy takes out the energy, moving energy,

of the ship.

[Narrator] 110,000 tons of rock are blasted and dropped

overboard to create the berm seven feet below the surface

of the sea.

Now, having finished dropping rocks outside,

they have to follow the plan for the inside to the millimetre.

The devil is in the detail.

It's a fairly complex building when it comes

to functionalities.

[Narrator] At its heart is the main stage,

which will serve both the national opera and ballet.

We have about 300 different computerized electro models

which are running all of the operations inside the stage.

So you can shift with turning things and sinking things.

You can push it in from the top, you can push it in

from the sides.

[Narrator] The main auditorium is designed to hold

almost 1,400 people.

The traditional horseshoe-shape guarantees clear views

of the stage.

But it also needs to be engineered

to provide perfect sound.

[Kjetil] We have to deep dive into the elements of acoustics

and understand what type of acoustics.

You know, it depends on the education of opera singers.

Do you have a pressure voice or do you have a soft voice?

What is your preferred kind of style?

Or do you have language understandability,

or do you have more on the music side of filling the room?

[Narrator] The key measurement is called

the room's reverberation time, the time it takes for sound

from the stage to reach the rest of the hall and then diminish.

Usually, a reverberation time of between 1.5 and 2.5 seconds

hits the sweet spot, quick enough for vocal clarity,

long enough for musical tones to develop.

[Kjetil] The singers should hear themselves.

You should hear the orchestra without any pre delay.

When the singer opens his or her mouth,

you should hear the sound immediately.

[Narrator] The team's solution partly comes down

to the materials they pick.

They line the auditorium with American oak,

which looks beautiful and has great acoustic

and reflective properties.

When they test it, the auditorium's reverberation time

is measured at 1.8 seconds, perfect for a room

of its size and shape.

[Randi] The sound is amazing.

Actually, the acoustics is brilliant in this house.

It's one of the best I've ever had in an opera house.

[music]

[Narrator] Since its opening in 2008, ahead of schedule

and 52 million dollars under budget,

this incredible opera and ballet house has become much more

than a performance space.

With its fully accessible public roof,

handcrafted from beautiful white Italian marble,

it attracted 5 million visitors within its first three years.

[Woman] It's really nice that it's open access to the public,

it's great.

Not a lot of places you can climb on top of a building.

It's actually really nice, I like that.

[Kjetil] While you're sitting on that spot on the roof,

it's your roof.

It's giving us this possibility of relating it back

to human experiences and intimacies,

and hopefully by that, creating public ownership

to the building.

[Narrator] And in the world of opera and ballet houses,

that's what's known as a box office smash.

[music]

Our next building is a museum that's almost

entirely recycled stuff.

Now, I'm not saying most of the objects on display are recycled.

Oh no, those things are all originals.

What I mean is the museum itself is built

using recycled stuff.

15,000 cubic metres of recycled concrete.

5,000 tons of recycled steel.

With its living roof and built-in rainforest,

here's a museum that's actually making history.

[Narrator] In Golden Gate Park,

on the west side of San Francisco,

a truly amazing new building has arrived.

A unique museum that combines breathtaking architecture

with thousands of exhibits.

If you think of a museum as a place full of old dead things,

then this place will blow your mind.

[Narrator] When one of America's leading scientific institutions

needed a new home, they decided to make it like nothing else

on the planet.

This building is really groundbreaking

because it really arrives in a time

where we were just really getting serious

about sustainable design.

[Narrator] It had to be tough enough to survive

in an earthquake zone,

green enough to set an example to the world,

and kind enough to support a whole host

of different plants and animals.

[Hayley] Entirely different ecosystems

at different temperatures, humidity,

even different types of seawater.

[Narrator] It's the only place on the planet

with an aquarium, a planetarium, a natural history museum,

and a four-story rainforest all under one extraordinary roof.

The architect had this vision of lifting up a section

of the park and putting a building underneath.

[Narrator] A visionary design that would create a building

so radical, it barely looks like a building.

This is the California Academy of Sciences in San Francisco.

So, how did they build it?

[music]

[Narrator] In 1853, the first scientific academy

on the Pacific Coast was founded in San Francisco.

Thousands flocked to see stuffed animals, rare artefacts,

and collections from around the world.

For over 130 years, the institution withstood

not only the test of time, but also several major earthquakes.

By the 1980s, the academy had grown, and on its site

in Golden Gate Park, the collection extended

over 12 buildings.

But when the Loma Preita earthquake hit in 1989,

it damaged some of the buildings beyond repair.

Determined to turn this catastrophe into an opportunity,

the academy decides to build one incredible new facility

to replace all 12.

Several well-known architects are invited to pitch

for the design of the museum.

And one in particular stands out.

Most of them made big slide decks with visions and numbers

of how they would make a difference, et cetera.

And Renzo Piano was totally different.

He made a sketch where he just basically said,

what if you could lift up a section of the park?

You put a living roof on top and put the building underneath.

[Narrator] Taking inspiration from the seven rolling hills

of San Francisco, Renzo Piano's museum will appear

to have risen out of the ground.

The roof will contain 1.3 million plants

to help control rain water on the building.

Instead of air conditioning, natural airflow will pull

cool air in at the bottom and push warm air out

through the roof.

A complex water filtration plant will supply the aquariums

with the right conditions for their exhibits to survive.

Slimline design will keep concrete pillars to a minimum,

while sustainable construction methods will help

create a building for the future and set the bar

for museums around the world.

Work starts in 2005, and the first challenge facing

the engineers is making sure this extraordinary building

is going to be tough enough to survive

in a major earthquake zone.

San Francisco is a seismic zone four,

which is the highest.

So we get some pretty big earthquakes coming through.

We've developed a lot of ways of dealing with quakes

when constructing new buildings.

Whatever you do, the key is not having the building tied

to the ground during a quake, which would transfer

the movement of the ground straight into

the building above.

[Narrator] But the engineers not only have to do this,

they have to do it without compromising the look

of the building.

[Alisdair] It's really like a huge shoebox

and reinforced concrete.

And it's big enough that by

allowing that entire basement level to rock

and flex a little bit, dissipates quite a bit

of the seismic energy,

so that the stuff inside the art exhibits don't get

thrown around.

[Narrator] With a plan in place to ensure

tremors aren't transferred into the museum,

the next challenge is making the building

environmentally responsible in its construction.

This building was designed to honour the living world.

And so really, it is about honouring that relationship

between people and the natural world.

[Narrator] It's a big challenge at a time when the building

and construction industry accounts for almost 40%

of the world's carbon emissions.

This project tries to change that.

First, almost all the demolished materials are recycled.

In the new building, half the lumber comes

from renewable forests.

And 95% of the steel is from recycled sources.

Even the insulation comes from an unusual place.

The walls of this building are filled with recycled jeans,

which is kind of an amazing thing unto itself.

Normal insulation has formaldehyde

and all these chemicals in it that you really don't want

in a building.

Recycled jeans have many of the same or better properties

than traditional fibreglass insulation in terms of

holding in heat, et cetera...

Soundproofing, all these things.

And of course, you're recycling and there's nothing toxic

in them, so this is the level that people went to

to make this building sustainable.

[Narrator] And as the birthplace of denim jeans,

some 150 years ago,

San Francisco could not have chosen

a more suitable material.

Next, they have to minimise the need for air conditioning.

[Christopher] One of the unique exhibits is the rainforest.

So that's a challenge in terms of the mechanical system

that's providing, you know, the right kind of humidity

and temperature that's appropriate for the plants

and the people.

[Narrator] Instead of relying on artificial heating and cooling,

they look to use the location itself.

[Alisdair] We thought, well, the climate in San Francisco,

particularly close to the ocean and Golden Gate Park,

is pretty mild.

I think with that shape of building and the big open space,

and that the hills, we can make the main exhibit space work

as a naturally ventilated space.

[Narrator] Architects use the curvature of the roofline

and the height of the halls within the building

to limit the need for air conditioning.

It's known as the stack effect.

[Christopher] The cool air comes in from below and then rises up

through those openings.

And that's really the beauty of this building,

is it's, it is breathing, therefore making it

much more efficient and using a lot less energy...

Up to at least 30% energy than a building like this

would have otherwise.

[Alisdair] So what we have is at

a little bit above the planetarium,

because that gives off a lot of heat,

and above the tropical rainforest,

all those round portholes.

Those openings are all computer controlled.

So as the temperature inside the space builds up,

they will start to open.

[Narrator] As work continues, not only does the building

need to blend in with nature, it has to bring nature inside.

Including the ocean.

[Brenda] The Steinert Aquarium is one of the oldest

and most biologically diverse aquariums in the world.

We opened in 1923 and have had a very long and rich history

of exhibiting rare and unique species.

[Narrator] The plan is for a new super aquarium

to be housed in the Academy of Sciences building.

It will be one of the largest and deepest coral reef exhibits

in the world.

That's if the team can work out how to build a tank

to hold over 200,000 gallons of water.

[Alisdair] The big coral reef exhibit

I think's about 15 to 20 feet deep,

and that's a lot of pressure down at the bottom,

trying to push out.

The concrete enclosures for the tanks was part of

the structural design, but then the acrylic sections

in those big tanks are curved.

And from a structural standpoint, a curved structure

is stronger for resisting pressure than a flat one.

[Christopher] In the aquarium,

you've probably seen the massive acrylic wall

that was, you know, no seams.

It was, at the time, the largest acrylic structure.

It had to be ordered, manufactures, and installed

prior to most of the building going up around it.

[Narrator] The next challenge is creating the perfect water

for each of the different habitats in the aquarium.

All of the water that we use for the aquarium

actually starts with one source,

and that's San Francisco city water.

From there, we run it through filtration

to remove chloramines, and then we either send it

to our freshwater basin for our freshwater habitats

or to saltwater mixing, where we create our own salt water

from our own special recipe.

[Narrator] The team builds the system into the basement.

It requires over seven miles of pipework to supply the aquariums

with the perfect water for their inhabitants to thrive.

One of the challenges is the coral, the coral reef.

You know, that was live coral that was brought in.

But before it was brought in, you know, the water

had to be right, the lighting had to be right.

And then you install the coral and you hope that,

you know, you have to watch it and maintain it.

[Narrator] By summer 2008, 19 years after

the Loma Prieta earthquake ripped through San Francisco,

the new academy throws open its doors to the public.

It's buildings like this, and programs and exhibits

like the kind that occur in this building,

that really encourage large numbers of people

to think differently about their relationship with nature.

[Narrator] Along with a colony of penguins,

a 90-foot high rainforest, a full-size T-Rex skeleton,

and an albino crocodile, over 40,000 live exhibits are put

on display to the public.

[Scott] We've had 17 million people

walk through this building...

More than since it opened in 2008.

So we can have a significant impact in the world.

[Narrator] The huge curved window offering a glimpse

into an undersea world,

the sustainable system cooling the building,

the enormous living roof on top...

It truly is a success with the scientific community

and the general public alike.

It really did set the bar very high

because it's an incredible building that's beautiful,

very functional, and also incredibly sustainable.

[Narrator] The structure is living proof

of an incredible idea turned into

an extraordinary reality.

One that continues to inspire visitors every day.