Lets reuse building parts
i’d like to speak about buildings
we all know buildings right we were born
in buildings
we were raised in buildings most of us
are working in buildings we may even die
in buildings but let’s forget about
us for a while and let’s focus on the
building lifecycle itself
if we want to create a building the
first thing we would need to extract
materials we would need to process
that material in order to manufacture a
new component
and we will assemble those components
according to plants
and the plans will vary a school is
different from a factory
a house is different from an office
building
we need different spaces we have
different needs
and so we are building we are
constructing our buildings
according to our needs but our needs
evolve quite fast
and the building lifespan is quite long
just to give you an example
60 years ago there would have been
always a war in between the kitchen
and the living room today we don’t build
that wall anymore we don’t need it
another example two years ago
before the pandemic started no one would
have expected
that most of the students most of the
employees would have to work from home
in a separate office in their own house
in their own apartment
right next to the kids to the friends to
the family
so our needs are evolving quite fast the
good news is that
building can adapt that we can add a
wall we can remove a wall
we can extend the building we can
replace the envelope we can
transform an office building into an
apartment building and vice versa
but at some point the buildings will not
be able to adapt
anymore and we will have to replace it
at some point any building may become
obsolete it may happen
in 20 years from now it may happen 100
years it may happen in 200 years we
don’t know
but what we know is that we are
demolishing buildings on daily basis
today
and this is an environmental issue
today one third of all solid waste in
europe
is due to the construction and
demolition of buildings
today at least 11 of all greenhouse
greenhouse gas emissions
related to human processes are due to
the construction
the transformation and the demolition of
buildings
and these numbers do not take into
account the greenhouse gas emissions
related to
the operation of the building so the
heating the ventilation
the cooling and the electricity in the
buildings this at least 11
of greenhouse gas emissions are just
related to the construction
the transformation and the demolition of
buildings
and these numbers these amounts will
grow in the next
years the main reason is that the world
population
will grow in the next 50 years mainly in
urban areas and that will put more
pressure on existing buildings
because sustainable cities
will have to grow from within that means
that
smaller buildings will have to
leave room for bigger buildings
so there are reasons why we are
demolishing buildings and it’s very hard
to go against that
but the real issue here is that whenever
we demolish a building
we actually throw away its parts as well
its beams its doors its slaps its
windows
but those parts are still performing
well most of the time the reason why we
demolish a building is because we don’t
use it
and we don’t need it anymore we don’t
need it at that
location at that point in time
but still safe buildings its slabs can
still be used as slabs
its columns are still good columns doors
are still good doors
so here is my question
why aren’t we allowing those components
to outlive the depths of their building
and why aren’t we reusing those
components in new configurations
elsewhere for new purposes
because every reused component is a
component that is not manufactured
imagine the amount of waste that could
be avoided
imagine the amount of greenhouse gas
emissions that could be
avoided this is not my idea this is not
a new idea this is actually a pretty
common sense idea
that people applied in the past on a
daily basis
just to give you an example here is a
bridge built in 1810
over the rhine at the border between
switzerland and
and germany it’s a very nice
timber-covered bridge
but 100 years later engineers decided to
replace that bridge with a bigger one
and the story is very interesting
because
parts of the beams used in dead beams
have been moved and used in order to
build
this newborn in the village nearby
and if you look at the cuts of the
columns on
that barn we can actually see the traces
of the past of these columns we can see
the heritage the embedded heritage of
the previous uses of these columns
so this bound was built in 1920
and it’s still in use today 100 years
later
so what do we have here in front of us
we have a 100 year old building
that is made of 200 year-old components
and that’s really the spirit of reuse
the goal of the reuse strategy is to
expand the lifespan of the component as
much
as we can even if it means that those
components
are fulfilling new purposes
today reuse is one of the few strategy
that
will allow to to reach a circular
economy
alongside with the recycling strategy
we all know about recycling but it’s
actually completely different from the
reuse
strategy whenever we recycle material we
would reprocess it
we’d apply energy we would transform it
we would melt it we would
crash it in order to create a brand new
material
but in the real strategies we don’t want
to touch the component
we want to reuse it as it is we want to
benefit from all the embedded value
inside the component that is already
there
and the application of reuse and
circular economy can bring a lot of
benefits it can allow us to reach
more environmental sustainability to
reach more
economic sustainability and more social
sustainability as well
but the truth is that today reuse is not
common at all and there are reasons why
there are indeed technological barriers
there are legal barriers
and there are also psychological
barriers white psychological barriers
because we we as humans we tend to be
afraid of things that
we don’t know and this is a real issue
whenever
we have to reuse components
but i believe that those barriers are
temporary
and must be tackled now and for that
reason i’m leading
a team of wonderful researchers
architects and civil engineers
and our aim is to explore new ways of
reusing components
such as to contribute to the fight
against climate crisis
and to avoid any potential future
resource
crisis
the very source project that we did was
to build
this pavilion made of skis
thousands of skis are thrown away every
year
and ski is a composite material that’s
very hard to recycle
but there is a very useful technological
value
embedded inside those keys so why don’t
we reuse it
are we gonna save the world with keys
and buildings well no
definitely not but there are a few key
takeaways that we can
get from this experiment the main one
is that we show that we can build high
performance structures
structures with very complex mechanical
behavior
while not controlling everything about
the material that we put in place
we don’t know these keys we don’t know
where they come from
they are all different we don’t know
what they are made of
we don’t know their mechanical
properties
but it’s okay we can build enough
confidence
in order to make sure that the the
structure
is safe and it’s all that matters we
don’t have to
control everything
and so we are helping our architects and
engineers to
make more reuse in their practice
and if we look at the design process
itself
we’re actually facing a completely
different
um problem
in a conventional design process the
designer would first
draw the overall shape of the structure
and then little by little more
information will be discovered
until we know exactly how we want to
manufacture the components
we know what properties we want to have
what length we want to have
we know what materials we want to use
but whenever we deal with an existing
stock
of elements
those properties they are given the
length
of the components are given their
dimensions are given their mechanical
properties are given
the material is given as well and we
have to deal with that
and the new goal now is to find the best
shape
the shape that will make the best reuse
of these components
so we are developing algorithms and
tools in order to automate
part of this process and we’re also
applying these tools to case studies
and here is a case study performed by a
master student
he actually designed a roof truss for a
train
station out of elements
that are only coming from dismantled
by electric pylons and those electric
pilots are
actually about to be dismantled in the
area
and with that case studies but also with
all the other key studies that we do
whenever we compare two steel traces for
instance
one in one scenario made with reused
components
and the other scenario made with brand
new components newly manufactured
components with recycled content in them
so whenever we compare these two traces
what we see is that in the reuse
scenario the mass is always bigger
usually we would say it’s an issue but
actually it’s okay i mean
just there because we are not using the
material in the most efficient way
but what matters is that in all cases
greenhouse gas emissions related to the
contraction
of the reused scenario
are lower than the one in the new
scenario
and this is what matters if we want to
lower
global warming
there are many questions that have to be
addressed as soon as possible
we are also looking at how the reuse
potential
of existing building stocks can be
assessed
on a large scale on a territorial scale
we’re also
also looking at ways to better reclaim
existing reinforced concrete slabs and
walls in buildings
and last but not least we are also
looking at new ways
to design slap systems that can be
reused in the future
with new spans in between columns with
new floor plans with new loads applied
to them
without oversizing the components the
slabs themselves
we don’t know what the future will be
about we don’t know what will be the
needs
in 100 200 years for now what buildings
we’ll
have to to to provide
but doesn’t mean that we cannot try to
ease the dismantling
of the components we put in place today
and it doesn’t mean that we cannot try
to make sure that
those components can be reused in new
unknown configurations
so in conclusion the message
here is that if we want to fight the
climate crisis
if we want to avoid any future resource
crisis
we have to give more value to the things
that already exist
we have to give more value to the
buildings that already exist
we have to keep them to maintain them as
much as we can
but once those buildings cannot exist
anymore and there are reasons why
at some point any building may not exist
anymore may be demolished
then at that moment we have to make sure
that
components the parts of these buildings
their slabs their walls their currents
their doors
their windows we have to make sure that
those components
are reused in new buildings in new
locations
in new configurations for new purposes
and last but not least for new
generations
of users thank you very much
you