Published 1 year ago.
About a 25 minute read.
Image: Circle House is Denmark’s first social housing project built according to circular principles. | Creative Denmark
The latent circular revolution is slow in getting off the ground in construction — but it’s time to reimagine and transform the industry. Here we explore eight key shifts to help construction actors rise to the circular challenge.
we connected the dots between radical climate action and the opportunity
presented by a circular economy, focused on the re-use of vehicle parts — and
how an emphasis on reuse and refurbishment, rather than downcycling, can enable
up to 50 percent savings in embodied carbon emissions, while also preserving 98
percent of commercial value.
While the climate math certainly stacks up for reuse in the automotive value
chain, how transferable is this insight for other sectors? In this third and
final part of our series, we’ll investigate how the construction sector — with
its massive climate impacts — can take a radical leap towards embracing circular
Buildings are responsible for 39
percent of global energy-related
emissions — split between lifecycle emissions for heating, cooling and power at
28 percent; and embodied emissions associated with materials and the
construction process at 11 percent. While lifecycle emissions have tended to
receive more attention in recent years — through improved thermal performance of
buildings and utilising renewable energies — embodied
provide the next big challenge in this important sector.
The World Green Building Council calls for a reduction in both embodied and
lifecycle carbon — with a special emphasis on reducing embodied emissions,
towards net zero by 2050 — supported
with a near-term target of 40 percent reduction in embodied emissions by 2030.
Tackling this important challenge will mean a complete rethink in resource
selection and management.
But, that’s OK; there’s plenty of opportunity to exploit. The construction
industry is the single largest consumer of resources and raw materials on the
planet, consuming more than 3 billion tonnes of virgin
each year. The industry is also notoriously wasteful: construction and
demolition waste (CDW) accounts for roughly one-third of total waste in
and around 40 percent of solid waste in the United States. And while there
has been a big emphasis on recycling of CDW — in the UK, 90 percent of all CDW
— these materials are mainly downcycled for future use as aggregates, so the
opportunity for reuse and preserving embodied emissions has yet to be harnessed
in any meaningful way.
With its scale of impact and opportunity, the construction sector should make a
vital contribution towards reducing embodied emissions by embracing circular
principles. According to the European Environment Agency, circular
strategies in buildings can deliver up to 61 percent savings in
— so, the potential for reining in industry impacts is huge.
As Sara Edmonds, Director of Studio
seARCH architects and coordinator with
Architects Climate Action Network, puts it: “We need to completely
moving from degenerative to regenerative
This revolution in thinking will need to include the drive for circular systems;
but how can we close the loop in
linking extensive reuse and recycling with radical reduction in embedded carbon
It’s time to completely reimagine construction — based on new possibilities — by
joining up all the dots on eight interconnected shifts that will help us deliver
circularity and radical climate action at scale in the industry.
The first shift starts with a simple question: Do we really need to build at
all, or could we repurpose an existing facility? After all, the most
sustainable building is the one we don’t need to build, right?
At first glance, there is nothing new or spectacular about the idea of
repurposing old buildings. Yet, there has been a tendency to dismiss this
obvious opportunity in recent times, in the pursuit of shiny new offices, shops
and housing. Yet, if we look through a different lens, we can start to
appreciate the amazing range of resources and new possibilities available to us
through these untapped assets.
There are millions of empty
homes and many vacant commercial
buildings around the world. In the UK, a staggering one in seven
are left vacant as the economy and retailers struggle to cope among economic
shocks and commercial shifts. How could these facilities be put to better use?
Repurposing redundant factories in the
presents a great opportunity for on-shoring and re-localising economic activity
(generating jobs within a more circular economy, perhaps?).
By reframing our needs, we can start to see existing facilities as a canvas on
which to paint a new, vibrant picture of a more sustainable built environment.
For example, the collapse of Debenhams plc — a former chain of 160
department stores across the UK, Denmark and the Republic of Ireland —
created the opportunity to repurpose vacant retail facilities.
The former Debenhams store in Sunderland, UK, has been reinvented as Prop
— an arts venue and community hub — incorporating a music venue, record shop,
café, gallery, kitchen, youth mental health trust, and a market for teenagers to
sell products. The £1 million renovation project took 3 years to complete —
restoring an existing asset to useful purpose and delivering much-needed social
improvements, while avoiding the creation of unnecessary demolition waste and
the future impact of embodied emissions associated with a new build project.
There will, of course, always be situations where organisations might still
prefer new buildings. Leading retailer and sustainability pioneer M&S
recently reached the controversial decision to demolish and rebuild its aging
in Oxford Street, London. Opponents of the project have warned that the new
structure will generate additional embodied emissions to the extent that would
require 2.4 million trees to be planted to offset the new build. To provide some
perspective: Offsetting this single project requires almost as many new trees as
are planted across the whole of
in a single year.
The scheme’s architects pose a reasonable counter argument, asserting that it’s
not always right to refurbish old structures — pointing out that the new
building will generate much lower lifecycle
and will embody much less carbon by reusing 90 percent of existing materials.
The architects estimate that the total footprint of the new build project will
break even after 16 years, which means that net carbon savings will start to
accumulate in 2043 and beyond. Although, there is clearly a significant burden
of new upfront emissions generated in the short term — a point not easily
dismissed, as we face near-term targets for radical emissions reduction by 2030.
Furthermore, for M&S to maximise the carbon savings opportunity associated with
reused materials, it will need to minimise downcycling and maximise genuine
circularity — a rarity in construction practice at this present time. In
Northwest Europe, only 1 percent of building elements are currently
There will, no doubt, be good commercial reasons for choosing the rebuild
option; but it does feel like an opportunity lost for circular leadership and
Looking further, in practical terms, we might also start to appreciate the role
of our existing stock of buildings as material banks, providing a catalogue of
assets and resources with all those embodied emissions locked in. Through this
lens, we definitely start to see old buildings as a resource, rather than a pile
of waste to be discarded.
Taking this step requires us to transform our design process and philosophy to
reimagine buildings and infrastructure for circular demand and circular design.
UK GBC provides useful
for a new ethos in circular construction, designing buildings for ‘optimisation’
— including a focus on longevity, flexibility, adaptability, and design for
assembly, disassembly and recoverability. Sounds great; could it work in
The Circle House — a 60-unit social housing project in Lisbjerg, Denmark
— provides a living example of rethinking design through the lens of
not only considering functionality, aesthetics and value, but also accounting
for buildings as materials banks, considering what happens to their assets and
resources beyond their first intended lifetime.
Circle House challenges conventional the build-use-dispose model by designing
and using components that can be easily taken apart — somewhat like a LEGO
kit — with disassembly and reuse considered for every part of the building. As
we might expect for such an approach, a great deal of innovation was required.
For example, conventional concrete panels did not work for reuse; so the team
created a new type of concrete panel that could be easily assembled using bolts.
The building can be taken apart, simply by unbolting panels, ready for reuse in
Circle House also has a higher degree of flexibility during its lifetime, with
the opportunity to reconfigure layouts or extend units; and at the
end-of-first-life, 90 percent of its components and resources can be
retaining much of their initial value.
Circular design tends to place an increasing emphasis on modern methods of
construction — focussing on standardisation, mass production and factory-based,
While there is nothing new in prefabrication, there is now an opportunity to do
it better with design and construction structured and digitised around building
information modeling to provide an
accurate and integrated representation of a building across its whole lifecycle,
which also allows for collaborative working across multiple actors within a
single intelligent process.
Mexico’s VMD Prefabricated
can be ordered and customised online, and built in 99 days with sustainable
materials. Going further, Geoship’s bioceramic, climate-resilient dome
inspire us to completely reimagine housing design — a regenerative approach with
a design life of 500 years, with 90 percent less embodied
CO2 than a conventional home, and more affordable: almost 50 percent cheaper
than conventional-build housing. They look great, too. The visionary startup
plans to produce its home kits in automated microfactories throughout the US and
the rest of the world.
Design for circularity involves a major shift in design thinking, mindful that
we need to deliver radical savings in embodied carbon emissions. And, of course,
rethinking design drives us deeper into rethinking materials, specifications and
As Architecture 2030 CEO Edward Mazria
“By 2040, all building products should require no carbon to create.” That’s
where we need to get to on embodied carbon: real zero by 2040. It’s time for
more radical innovation in building products and materials technology.
We can already choose many inherently sustainable and low-carbon products and
materials — for example, sustainable or reclaimed timber, low-carbon steel
(SSAB is now producing fossil-free
in Sweden) — or even carbon-based
Our selection of suitable materials should be based on durability, value for
money and embodied carbon emissions; but we might also think about the potential
for reuse of circular elements and components, and keeping modular assets in
Image credit: Beyond Zero Homes
designed and built for the Glasgow summit by Beyond Zero Homes, provides a
great demonstration of what can be achieved using lower-embodied-carbon
materials within the context of circularity and reuse. The single dwelling
involves an emphasis on lower-embodied-carbon building products, especially
timber — which acts as a carbon store as well as a renewable material.
Altogether, this achieves a 59 percent reduction in embodied carbon emissions —
avoiding 78 tonnes of embedded CO2 — compared with a conventional house, or 22
percent reduction, when measured against the most stringent carbon target. This
radical leap in performance is achieved by careful selection of timber products
all through the house — even the roof covering is timber! Maximising
low-embodied-carbon design means much less reliance on offsetting in our quest
There’s one further materials advantage: COP26 House also stores more than
double its embodied carbon in terms of biogenic (sequestered) carbon emissions.
Of course, biogenic emissions can be released back into the atmosphere, if and
when the building is demolished and products are disposed of through
incineration or decomposition; but COP26 house has been designed for disassembly
(using standard components) and reuse at the end of its 60-year design life,
ensuring the sequestered emissions remain locked into their natural carbon
As we rethink design and materials, it becomes evident that we will also need to
source and manage our resources in completely different ways.
By placing more emphasis on material banks within existing buildings and
infrastructure, we need to completely reimagine materials supply and management,
creating the need for new markets and logistics solutions for used materials at
International property company Grosvenor Group is picking up the challenge.
Project Director Steve
imagines a future where all elements are tagged with readily accessible data,
where the used materials from a redundant building are simply removed and resold
on a second-hand market: “Future design should be more flexible in its
specification to allow a range of materials sourced on a second-hand market to
be used… carbon will be at the centre of it all, and surely re-used is better
Taking the challenge forward, Grosvenor is seeking partners to explore new
approaches for materials reuse in London. It might, perhaps, draw inspiration
from developments in other markets, when thinking about developing new suppliers
and supply markets.
Genbryg.dk is Denmark’s largest online shop for used
building materials, with over 76,000 products in stock and over one million
webshop visitors every year. The company specialises in the purchase and resale
of used building materials — including used doors, windows, lamps, floors, door
handles, timber and much more. Genbryg has its own design studio, which develops
sustainable interior design concepts for restaurants and shops. It has also
produced 1800 m2 of refurbished wooden wall
panels for the prestigious Copenhagen
Towers development in the Ørestad
district of Copenhagen.
Lendager UP is another Danish company,
originally founded because of the lack of suppliers for upcycled building
products. The circular resource company works with resource optimisation and the
development of upcycled products, to ensure the value of used materials is
maintained and enhanced — ideally creating a product with an even longer
lifespan than the original. This process requires total stewardship and
lifecycle management of products and materials.
For a number of years, Lendager UP has prepared material analyses of older
buildings and calculated the value of demolition fields. It sees a future where
all old buildings are digitally registered with the necessary data in the form
of material passports; Lendager UP has developed digital material passports on
the Circle House
In response to the need for a new supply market, Lendager UP has effectively
developed an interesting template for a new type of circular resource company —
an essential new position within a circular construction value chain. Materials
stewardship is needed throughout the construction process, not least at the
demolition end of things.
Image credit: Unbuilders/Facebook
Let’s switch continents for a great example of a company that has really sought
to rethink the demolition process, fully integrating the idea of materials
stewardship. Unbuilders — a great name to start with — is a company of
salvage experts based in Vancouver, Canada.
Basically, Unbuilders takes buildings apart to maximise reuse and minimise
waste. Of course, any demolition contractor worth its salt, these days, will
claim to do the same. Yet, we can only watch and marvel at the care and
precision taken by Unbuilders’ team of carpenters, roofers, framers and trades
people, as they painstakingly disassemble
properties layer by layer — upcycling
resources into the supply chain. Recovered wood from a 1930s property was
remanufactured into bars, floors and table tops at a local restaurant; the team
achieved a salvage and recycle rate of 99 percent.
Their impressive ‘harvesting’ process also helps to enable societal benefits —
deconstruction is understood to generate up to six jobs for every single
traditional demolition job.
Ah, but surely this labour-intensive process will be much more expensive? Well,
here’s the thing: With careful business model innovation, Unbuilders can provide
its more-sustainable service for almost half the amount of a traditional
demolition service. The key enabler here
is the ability to attract federal and provincial tax credits, which more than
offset any premium in process cost. In one sense, this model might be considered
subsidised; while any traditional demolition process will involve many hidden,
unpaid costs — treated as ‘externalities’ — such as the cost of waste and
Going forward, we can all expect to pay the ‘true costs’ of doing business in
all sectors, starting with carbon
— but also widening the field to full natural capital
Getting to ‘true cost’ will tend to correct any market price anomalies and
render sustainable solutions more cost-effective, every time.
While the Unbuilders example focuses almost exclusively on timber dwellings, it
shows us what is possible if we can reimagine demolition for all building forms
and infrastructure — maintaining products and resources at their highest level
of use, becoming stewards of circular materials, and drawing on business
innovation to ensure the proposition works commercially.
From this point, we can then start to imagine building out the rest of the
circular construction value chain — configured to manage and restore building
assets, products, materials and resources.
Building the circular value chain in construction will necessarily involve new
partnerships and collaborations.
Both Circle House and COP26 House involve collaboration between actors through
the entire value chain. Development of the Circle House project involved
collaboration across 25 different
— including architects, circularity consultants, entrepreneurs, contractors, the
municipality, component manufacturers and materials suppliers — all taking time
to explore issues and questions that had never been considered on construction
projects. It’s not possible to develop this level of circular innovation without
Going through this process raises all sorts of questions about the role that
various actors might play, going forward. We cannot expect to develop the
circular value chain without making changes in what we do. We might consider the
role of the contractor, for example: Should we remain engaged simply as
constructors of buildings; or do we extend our position, towards becoming
stewards of zero-impact buildings and reusable resources within a circular
Do we have the capabilities to fulfil this role, as we are currently configured;
or do we need to work in partnership with materials suppliers and logistics
companies to develop the necessary infrastructure for managing circular products
and resources? Perhaps, we might even take the strategic opportunity to acquire
and vertically integrate these new core competencies? And, if contractors don’t
act, someone else will, no doubt, fill the void; perhaps new market disruptors
will create a completely new type of construction company?
But, of course, for circular construction to really take off, it has to work
commercially, as well as practically.
Going circular in construction means designing for longer, multiple-useful-asset
lives. This will require us to design and manufacture high-quality, longer-life,
reusable circular products, but will most likely mean our buildings become more
Perhaps not. Through business model innovation, there is an opportunity to
spread the apparently higher initial costs of production across multiple,
extended product lifecycles. We don’t necessarily have to recover all production
costs at the initial point-of-sale; if asset producers retain ownership of
circular assets and products, this enables both life-long responsibility and
income, while ensuring greater affordability for each building user.
This model will, of course, have implications for business cashflow, as we
experience in all circular leasing/rental business models, but this shift has
been very effective in other
where it can be 25 percent cheaper to rent high-quality products, rather than
buy cheap linear-economy items. The key to circular commercial success is all
about extended product lifecycle, enhanced resource utilisation, with less money
tied-up in resources and waste, enabling more value to be shared between
customers, retailers, manufacturers and suppliers. We can learn much from this
Similar levels of commercial innovation can also work in construction. The
municipality of Venlo in the Netherlands wanted to construct its new town
hall using only reusable
The building was designed based on circular principles, including designing for
disassembly and materials banking, and with long-term material health in mind. In
terms of procurement, the project involved an innovative commercial deal to
incentivise materials stewardship: The client asked material suppliers to
provide guaranteed take-back systems at the end of the building’s life, which
would guarantee that materials keep their residual value with pre-agreed prices.
This long-term perspective creates a continuous cycle of resources, and
incentives for maintenance and lifecycle management of resources.
This approach requires a different approach to cost planning and management — to
include accounting for the residual value of assets, and ensuring that materials
harvesting is commercially viable. And clearly, the ability to capture
value through disassembly presents a major opportunity.
As Anders Lendager of Lendager UP realised, there are large sums of money to be
saved by harvesting resources for circular construction. On one of its
projects in Norway — a business area being converted to 450,000 m2 of
residential development — Lendager prepared a material analysis of the entire
project, and found roughly $160 million of building parts
including windows, doors and many other components that could be reused. The
building contractor then harvested these resources as assets, towards the
construction of the new building. There’s more money to be made in circular
resources than there is in linear waste!
Harnessing this opportunity requires a shift in mindset; no longer seeing used
resources as waste, but as a viable economic resource. There is clearly a major
opportunity to scale-up resource bank thinking across the entire construction
value chain, harvesting and managing resources and creating new supply markets.
This shift in commercial innovation can feel like a bridge too far for
players; it really does challenge our thinking on how and when we make our money
in construction, and requires a more holistic mindset to appreciate new forms of
commercial innovation for circular business success. Which brings to our eighth
and final shift, underpinning the whole circular transformation, the need to
reimagine skills and capabilities.
There are clearly major implications for the demolition sector, developing
harvesting at scale, but there are also changes for all actors through all
stages of the construction process, whether in briefing, design, procurement,
cost planning, construction, logistics, and so on.
For example, there’s a great opportunity for procurement and commercial teams to
take a leading role — repurposing and extending their commercial skills for
circular commercial innovation, including: whole-life cost modelling, managing
costs over multiple asset lives, finding new ways of making money (business
models), ensuring affordability, and developing the maturity and scale of supply
markets for new and innovative materials.
The common thread across all functions is the need for a mindset shift,
involving systems thinking: seeing integrated sustainability and circular
principles as an opportunity, not a burden; liberating and unleashing new
creativity, ideas and solutions; experimenting and challenging standards.
Without this shift, we remain stuck within same paradigm, destined never to
It is interesting to see the emergence of new educational programmes for
circular construction at places such as TUDelft in the
and University of Brighton’s School of
Re-Construction in the UK; but there are major implications for
mainstream education and skills provision at all levels.
The recent report by Green Alliance explores what is needed to close the green
skills gap in the
A much needed report, which includes a focus on construction skills, and further
consideration of the circular economy, but doesn’t quite join-the-dots and
develop new insights for circular construction skills. There’s clearly more work
to be done on developing skills provision for circular construction.
Above all, we need what Paul Polman calls courageous
— unafraid to try bold new approaches: “so strongly purpose-driven that they
understand it is uncomfortable to set targets that you don’t know how to
achieve, but that are needed.” Without courageous leadership, we will see
little real change.
A circular economy offers the single biggest opportunity for radical climate
action in construction, which could deliver 40-60 percent reduction in embodied
While there is little visibility on global progress towards circular
construction, we do know that only 1 percent of building elements are currently
following their first application in North West Europe. A large number of
elements are technically reusable, they end up being recycled by crushing,
melting or disposal. The result is a high environmental impact and a net loss of
economic value — we can and must do better than 1 percent reuse.
Can any serious player in the construction industry hope to deliver net zero
without embracing a circular economy? Yet, not many actors in the
value chain have developed robust circular economy strategies and, quite
importantly, made the essential link with radical climate action through
reduction or embodied emissions. There is much work to be done.
Arguably, a circular economy also offers the construction industry its biggest
catalyst for industry transformation in many decades; even more than strategic
procurement, partnering, supply chain
and lean construction were in the 1990s and beyond. This is a
once-in-a-generation opportunity to reinvent the industry for a sustainable
While going circular in construction presents a great opportunity, this also
means great change — a major challenge for all those that have prospered under
the old order, where relying on former glories can present a significant
barrier to innovation and change. Real change is hard.
We’ve been here before, of course. Each new challenge and industry review leads
to some level of improvement; yet despite pockets of great innovation, the
industry often tends to change less than is really needed, and over a much
longer period of time.
This time it has to be different: The scale of the challenge is enormous, and
the pace we need to move at requires a genuine transformation. This level of
change cannot be achieved in isolation by one or two innovative companies — a
circular transformation will necessarily involve the whole value chain, working
in concert to orchestrate circular and systemic
Have we got what it takes to go circular in construction? All the solutions
are there — we just need to join them up and integrate within a new construction
process. The only real barrier is ourselves. And to resolve this, we simply need Michael
Pawlyn’s mindset of
— taking greater agency to explore and create the new art-of-the-possible: “We
need plans for the future with numbers that add up.” We need to combine
evidence-based action with the ability to manage uncertainty.
And with that comes tonnes of low-carbon innovation, including a new model for
circular commerce. And, if we can crack this challenge within a complex and
entrenched sector such as construction, we can deliver radical climate action
Reimagine the need: Rethink current stock of buildings and infrastructure —
not just in terms of their form and function, but also their potential as
live resource banks to be drawn-down and reused at the end of each useful
Reimagine design: with design for circularity, longer lifecycles,
disassembly, refurbishment, remanufacture and reuse — aiming for 90 percent
reuse of components, rather than 90 percent downcycling.
Reimagine materials: Selecting only low-carbon, biogenic, reusable products
and materials set within the context of modular design for disassembly and
Reimagine sourcing and supply: with an emphasis on materials banks, all
construction products and materials harvested, and kept at their highest
level of utility and value — working with a ‘custodian’ mindset to manage
products and materials through multiple lifecycles.
Reimagine process: minimising waste, maximising reuse; where demolition
becomes resource harvesting and products and resources have digital
passports — enabling total stewardship and circular lifecycle management.
Reimagine value chains: based on circular collaboration, involving new
partnerships and collaborations, exploring challenges and new innovations,
leading to new roles, new types of business organisation and business
Reimagine commerce: incorporating business model innovation and cost
modelling, new commercial deals and incentives to enable long-term
management of resources and to capture continuous circular value.
Reimagine capabilities: Repurpose existing skills and expand the role of all
actors through the value chain, built on new integrated mindsets for
sustainability, circularity, systems thinking, and possibilism — augmented
with courageous leadership.
Published Mar 3, 2022 1pm EST / 10am PST / 6pm GMT / 7pm CET
Mike Townsend is founder and CEO of Earthshine — an international consultancy and training provider focused on circular and sustainability transformations in business, economy, and society — unleashing the capability within people and their organisations.