There are so many of these rectangle things everywhere.

Every new building.

There, they're subtle. They're there.

Right over there.

They're everywhere.

There.

OK, this isn't a fancy apartment building, but look at this! Kohl's.

Look at all those.

If you're living in an apartment anywhere from Minneapolis to Massachusetts

you'll see a pattern of rectangles on the facade just like this.

Buildings used to look like this.

Now they look like this.

But all these rectangles and textures are surface evidence

of a hidden system that's changed buildings.

Whether it's a big public development, like a library or private development

like apartment building

you can find panels that compose the facade.

I'm Matt Hogan, and I'm a project architect with Walter Parks Architects.

And I'm Walter Parks, and I work at Walter Parks Architects with Matt.

So this building is in an old and historic district, and so it has to fit in with the

historic nature of the other buildings.

And if you look at that building and you look at the building behind you, there's a band

the building behind you, at the top of every window.

And we have a band at the top of every window.

The running bond pattern mimics the bricks.

We're developing a palette of exterior materials that complement one another, but also hopefully

relate in some way to the neighborhood that the building is in.

My name is Andrea Quilici, and I am a senior associate at Quinn Evans Architects

and I'm a designer.

I mostly work on libraries.

There are three projects that we design at Quinn Evans.

So Libbie Mill is located right at the center of a new development.

We terracotta, we use high performance concrete panels

so that looks like concrete.

Varina is a very pastoral.

It's open, it's next to a beautiful creek that it's preserved.

And then we get to Fairfield this is much more suburban.

We want selected material that in some way resonate with this community.

We want to have a material durable, and we use the slate

because it's a material that everybody knows.

The visual choices are different, but these panels all serve a similar technical purpose.

And they're all only available now because of the evolution of building design

during the 20th century.

A number of trends have driven us towards actually building car dealership

and high rise apartment buildings in the same way that we built houses in 1920.

My name is John Straub and I'm a professor of the University of Waterloo in both the

Department of Civil Engineering and the School of Architecture.

A lot of serious houses that were meant to be permanent before 1900 would have been built

out of masonry, out of brick on brick.

They would have had plaster as an interior finish.

Brick is great like a big sponge, but it's super heavy

and requires the expense of a mason.

Those 1920 houses represented a different approach by using shingles

that protected the house from water

but weren't necessary to hold it up.

By the time we got to the Second World War, even serious houses

the houses for the town physician or mayor

were now being built out of wood framing lightweight systems.

If I were to go and say, how did we build a local school or community center in 1930

or even 1960, the answer would have been masonry.

But at the same time, even big projects were slowly shifting

to lighter, more flexible systems.

And as we got into the energy crisis, we even started to care about their energy efficiency

of how much it would cost to heat and cool them.

I'm the associate director of the Pennsylvania Housing Research Center.

We are a part of Penn State University in the Civil Environmental Engineering Department.

Our core vision is rooted in Pennsylvania.

It's to help that industry build better homes by making our buildings more energy efficient.

There was a bit of a lag in how we controlled moisture.

That is where the panels come in.

They're part of a system called rainscreen cladding.

It takes these high-tech insulated houses

and adds an air gap between them and a rainscreen.

Often, the fiber cement panels that are so recognizable, but other textures too.

It doesn't support the whole structure.

That's what the frame is for.

Imagine hanging a picture a half inch out from the wall.

Panels are simply hung on a track system.

As this installation video from one popular manufacturer, Nichiha, shows.

That rainscreen keeps a lot of water out, and what water does get through

has time and space to dry in the gap.

Instead of getting in the structure and rotting it just like those New England shingles did,

rainscreen cladding keeps water out.

But does it also use airflow to create a more environmentally efficient enclosure?

Creating the airflow to make it more efficient is its it's like vast—

like it's literally nothing.

It's a bee fart in a windstorm.

But I would say that there's a couple of factors

where depending on how you look at the environment

When I said that there's this trend to make, to use lighter weight less material

that is actually environmental.

I mean, if you were to try and build the buildings that are needed in the next 30 years

around the world and make them out of as many tons of material as we built them in 1940

the planet would just fall apart.

A rainscreen is nothing more than a concept, really.

It's a system.

It's not any one product, it's not any one technique.

It's an assembly and that can be applied to commercial buildings just as much as

it can be applied to residential buildings.

This technical adjustment and shifting thinking

led to a big change in what the outside of a building could look like.

I mean, there was a time where environmentally conscious building

was with sort of on the fringe.

And now I think because so many of these strategies have rain screens, for instance, have become

more mainstream, they're seen as best practice.

Our clients are mostly build and hold guys.

They're are long-term guys who want to hold that asset and don't want it falling apart.

They're really worried about what it's going to be in 20 years.

They've got a 25 year mortgage or a 30 year mortgage.

One of they key factors is, for example

is construction time.

What's interesting, for example, with this system is the fact that you can

enclose the building, dry in the building, independently from the facade.

So certainly availability of labor is a big one.

Cost is a big one as well.

It has structural implications.

Also, when you look at designing the structure of the home, adding brick will change

some of your details or require some additional additional structural design.

Easy to overcome, but any of those additional details they start to add up.

You see, if we think about the historic choices architects had in 1960, pick another date.

They didn't have a lot.

It was stucco or it was brick.

And then they had this sudden shock that they could do things like concrete.

And they had, like all 4 choices.

They were like, their minds were just exploding about the possibilities.

That obviously could have completely turned on its head today

because somewhere from the 1960s to the 2020s

we've gone to having maybe 3 or 4 dominant cladding types for walls

to having easy 40 or 50.