Michael Green Why we should build wooden skyscrapers

this is my grandfather 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

the 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 a small block of

wood if you stack it up tall actually

it’s an incredibly inspiring thing these

are by buildings I build all around the

world out of our office in Vancouver in

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 gonna 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 us steel or a concrete

column but I’ve actually seen that

happen in my 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 would gives Mother Nature

fingerprints in our buildings its 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

stories tall down the coast here in

California the redwood forest grows to

40 stories tall but the buildings that

we think about in wood are only four

stories 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% cities and density mean that

our building

are gonna continue to be big and I think

there’s a role for wood to play in

cities and I feel that way because 3

billion people in the world today over

the next 20 years will need a new home

that’s 40 percent of the world they’re

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 it’s 1 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 the

materials of the last century but there

are also materials with very high energy

and very high greenhouse gas emissions

in their process steel represents about

3 percent of man’s greenhouse gas

emissions and concrete is over five

percent so if you think about that 8

percent of our contribution to

greenhouse gases today comes from those

two materials alone we don’t think about

it a lot and then 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

the 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 3 billion

people that need a home and climate

change our 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 I’m

gonna 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 in a false to the

forest floor

it gives that carbon dioxide back to the

atmosphere 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 a

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 what is the only major

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

arts 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

storeys we need to reduce the concrete

and steel we need to grow bigger and

what we’ve been working on it’s 30 story

tall buildings made of wood

we’ve been engineering them with an

engineer in America and named Derek Carr

she 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 masts 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 sixty-four 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 constructions

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 you remember when

you’re a kid you kind of sift it through

the pile in your basement you found that

big twenty-four 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 masked upper panels are those

twenty-four dot bricks they’re changing

the scale of what

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

storeys 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

four 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 high

seismic zone even a 30 storeys tall now

obviously every time I bring this up

people even you know here at the

conference say are you serious 30

storeys how’s that gonna 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 in the peer-reviewed report I’m

just gonna focus on a few of them let’s

start with fire because I think fire is

probably the first one that you’re all

thinking about right now yeah fair

enough and the way I describe it is this

if I asked you to take a match and light

it and hold up a log and try to get that

log to go on fire doesn’t happen right

we all know that but to build a fire you

kind of start with small pieces of wood

and you work your way up and eventually

you can add the log to the fire and when

you do add the log to the fire of course

it burns but it burns slowly

well mass timber panels these new

products that we’re using are much like

the log it’s hard to start them on fire

and when they do they actually burn

extraordinarily predictably and we can

use fire science in order to predict and

make these buildings as safe as concrete

and a safe of steel the next big issue

deforestation eighteen percent of our

contribution to greenhouse gas emissions

worldwide as the result of deforestation

the last thing we want to do is cut down

trees or the last thing we ly do is cut

down the wrong tree there are models for

sustainable forestry that allow us to

cut trees properly and those are the

only trees appropriate to use for these

kinds of systems now I actually think

that these ideas will change the

economic

of deforestation in countries with

deforestation issue we need to find a

way to provide better value for the

forest and actually encourage people to

make money through very fast growth

cycles 10 12 15 year old trees that make

these products and allow us to build at

the scale we’ve calculated a 20-story

building will grow enough wood in North

America every 13 minutes that’s how much

it takes the carbon story here is a

really good one if we built a 20-story

building out of cement and concrete the

process would result in the

manufacturing of that cement and 1,200

tons of carbon dioxide if we did it in

wood in this solution we’d sequester

about 3,100 tons for a net difference of

4,300 tons that’s the equivalent of

about 900 cars removed from the road in

one year think back to that 3 billion

people that need a new home and maybe

this is a contributor to reducing we’re

at the beginning of a revolution I hope

in the way we build because this is the

first new way to build a skyscraper and

probably a hundred years or more but the

challenge is changing society’s

perception of possibility and it’s a

huge challenge the engineering is

truthfully the easy part of this and the

way I describe it is this the first

skyscraper technically in the definition

of skyscrapers ten storeys tall believe

it or not but the first skyscraper was

this one in Chicago and people were

terrified to walk underneath this

building but only four years after his

bill Gustave Eiffel was building Eiffel

Tower and as he built the Eiffel Tower

he changed the skylines of the cities of

the world changed and created a

competition between places like New York

City and Chicago where developers

started building bigger and bigger

buildings and pushing the envelope up

higher and higher with better and better

engineering we built this model in New

York actually on the as a theoretical

model in the campus of a Technical

University soon to come and the reason

we picked this site to just show you

what these buildings may look like

because they can the exterior can change

it’s really just the structure that

we’re talking about the reason we picked

it is because this is a Technical

University and I believe that wood is

the most

advanced material I can build with it

just happens to be the mother nature

holds the patent and we don’t really

feel comfortable with it but that’s the

way it should be

nature’s fingerprints in the built

environment I’m looking for this

opportunity to create an Eiffel Tower

moment we call it buildings are starting

to go up around the world there’s a

building in London that’s 9 storeys a

bit new building that just finished in

Australia that I believe is 10 or 11

we’re starting to push the height up of

these wood buildings and we’re hoping

and I’m hoping that my hometown of

Vancouver actually potentially announces

a world’s tallest at around 20 storeys

and the not so distant future that

Eiffel Tower moment will break the

ceiling these arbitrary ceilings of

height and allow wood buildings to join

the competition and I believe the race

is ultimately on thank you