This is my grandfather.

And this is my son.

My grandfather taught me to work with wood

when I was a little boy,

and he also taught me the idea that

if you cut down a tree to turn it into something,

honor that tree's life and make it as beautiful

as you possibly can.

My little boy reminded me

that for all the technology and all the toys in the world,

sometimes just the small block of wood,

and if you stack it up tall,

actually is an incredibly inspiring thing.

These are my buildings.

I build all around the world

out of our office in Vancouver and New York.

And we build buildings of different sizes and styles

and different materials, depending on where we are.

But wood is the material that I love the most,

and I'm going to tell you the story about wood.

And part of the reason I love it is that every time

people go into my buildings that are wood,

I notice they react completely differently.

I've never seen anybody walk into one of my buildings

and hug a steel or a concrete column,

but I've actually seen that happen in a wood building.

I've actually seen how people touch the wood,

and I think there's a reason for it.

Just like snowflakes, no two pieces of wood

can ever be the same anywhere on earth.

That's a wonderful thing.

I like to think that wood

gives Mother Nature fingerprints in our buildings.

It's Mother Nature's fingerprints that make

our buildings connect us to nature in the built environment.

Now, I live in Vancouver, near a forest

that grows to 33 storeys tall.

Down the coast here in California, the Redwood forest

grows to 40 storeys tall.

But the buildings that we think about in wood

are only four storeys tall in most places on earth.

Even building codes actually limit the ability for us to build

much taller than four storeys in many places,

and that's true here in the United States.

Now there are exceptions,

but there needs to be some exceptions,

and things are going to change, I'm hoping,

and the reason I think that way is that

today half of us live in cities,

and that number is going to grow to 75 percent.

Cities in density mean that our buildings

are going to continue to be big,

and I think there's a role for wood to play in cities.

And I feel that way because three billion people

in the world today, over the next 20 years,

will need a home.

That's 40 percent of the world that are going to need

a new building built for them in the next 20 years.

Now, one in three people living in cities today

actually live in a slum.

That's one billion people in the world live in slums.

A hundred million people in the world are homeless.

The scale of the challenge for architects

and for society to deal with in building

is to find a solution to house these people.

But the challenge is, as we move to cities,

cities are built in these two materials,

steel and concrete, and they're great materials.

They're the materials of the last century.

But they're also materials with very high energy

and very high greenhouse gas emissions in their process.

Steel represents about three percent

of man's greenhouse gas emissions,

and concrete is over five percent.

So if you think about that, eight percent

of our contribution to greenhouse gases today

comes from those two materials alone.

We don't think about it a lot, and unfortunately,

we actually don't even think about buildings, I think,

as much as we should.

This is a U.S. statistic about the impact of greenhouse gases.

Almost half of our greenhouse gases are related to the building industry,

and if we look at energy, it's the same story.

You'll notice that transportation sort of second

down that list, but that's the conversation we mostly hear about.

And although a lot of that is about energy,

it's also so much about carbon.

The problem I see is that, ultimately,

the clash of how we solve that problem

of serving those three billion people that need a home

and climate change are a head on collision

about to happen, or already happening.

That challenge means that we have to start thinking in new ways,

and I think wood is going to be part of that solution,

and I'm going to tell you the story of why.

As an architect, wood is the only material,

big material that I can build with

that's already grown by the power of the sun.

When a tree grows in the forest and gives off oxygen

and soaks up carbon dioxide,

and it dies and it falls to the forest floor,

it gives that carbon dioxide back to the atmosphere or into the ground.

If it burns in a forest fire, it's going to give that carbon

back to the atmosphere as well.

But if you take that wood and you put it into a building

or into a piece of furniture or into that wooden toy,

it actually has an amazing capacity

to store the carbon and provide us with the sequestration.

One cubic meter of wood will store

one tonne of carbon dioxide.

Now our two solutions to climate are obviously

to reduce our emissions and find storage.

Wood is the only major material building material

I can build with that actually does both those two things.

So I believe that we have

an ethic that the earth grows our food,

and we need to move to an ethic in this century

that the earth should grow our homes.

Now, how are we going to do that

when we're urbanizing at this rate

and we think about wood buildings only at four stories?

We need to reduce the concrete and steel and we need

to grow bigger and what we've been working on

is 30-storey tall buildings made of wood.

We've been engineering them with an engineer

named Eric Karsh who works with me on it,

and we've been doing this new work because

there are new wood products out there for us to use,

and we call them mass timber panels.

These are panels made with young trees,

small growth trees, small pieces of wood

glued together to make panels that are enormous:

eight feet wide, 64 feet long, and of various thicknesses.

The way I describe this best, I've found, is to say

that we're all used to two-by-four construction

when we think about wood.

That's what people jump to as a conclusion.

Two-by-four construction is sort of like the little

eight-dot bricks of LEGO that we all played with as kids,

and you can make all kinds of cool things out of LEGO

at that size, and out of two-by-fours.

But do remember when you were a kid,

and you kind of sifted through the pile in your basement,

and you found that big 24-dot brick of LEGO,

and you were kind of like,

"Cool, this is awesome, I can build something really big,

and this is going to be great."

That's the change.

Mass timber panels are those 24-dot bricks.

They're changing the scale of what we can do,

and what we've developed is something we call FFTT,

which is a creative commons solution

to building a very flexible system

of building with these large panels where we tilt up

six stories at a time if we want to.

This animation shows you how the building goes together

in a very simple way, but these buildings are available

for architects and engineers now to build on

for different cultures in the world,

different architectural styles and characters,

in order for us to build safely,

and we've engineered these buildings, actually,

to work in a Vancouver context,

where we're a high seismic zone,

even at 30 stories tall.

Now obviously, every time I bring this up,

people even, you know, here at the conference, say,

"Are you serious? Thirty storeys? How's that going to happen?"

And there's a lot of really good questions that are asked

and important questions that we spent quite a long time

working on the answers to as we put together

our report and the peer review report.