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