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