Conifera: How COS and Arthur Mamou-Mani Grew a Forest From Bioplastic

ART & CULTURE · MILAN

Reading time: 9 min

Seven hundred bioplastic bricks, printed across four workshops in two countries, formed a 30 metre structure that ran from a Milanese palazzo’s colonnade into its garden. Arthur Mamou-Mani built Conifera for COS using PLA, a bioplastic designed to be composted once the show came down, so that a temporary installation could close its own material loop rather than simply promising to. It was COS’s eighth consecutive year building something new at Milan Design Week, and the most direct argument yet for the architect’s belief that a building can be grown rather than built.

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For six days in April 2019, the courtyard and garden of Palazzo Isimbardi in Milan filled with a pale, faceted structure that looked more grown than built. Its name was Conifera, and it was the work of the French architect Arthur Mamou-Mani, commissioned by the fashion brand COS for its eighth consecutive year at Milan Design Week.

Conifera was made from 700 individual bio-bricks, each 3D-printed from a bioplastic derived from renewable plant starch, in a form called PLA. The bricks ran in a continuous lattice from the palazzo’s colonnaded entrance, through its 16th-century courtyard, and out into the garden beyond, tracing a line roughly 30 metres long and weighing just over two tonnes.

The structure took its name and its logic from the way conifer trees grow: dense and woody near the trunk, opening out into lighter, more translucent growth toward the crown. Mamou-Mani built that same gradient into Conifera’s material, moving from opaque, wood-toned bricks near the palazzo’s stone walls to clear, sugar-pale bricks further into the garden. The result was less an object placed in a historic setting than a structure that appeared to have grown out of it.

What makes Conifera worth returning to, several years on, is not only its scale or its material but its manufacturing model and its ending. Mamou-Mani had the bricks 3D-printed simultaneously in four separate workshops in two countries, all working from one shared parametric file, and he designed them from the outset to be decomposed once the installation was taken apart. Both of those facts speak to an argument he has been making for most of his career: that architecture does not have to be assembled from parts shipped in from elsewhere, and it does not have to leave behind more than it needed to.

What Conifera actually was

Palazzo Isimbardi is the historic seat of the Province of Milan, now the Città Metropolitana di Milano, a 16th-century palazzo whose courtyard and formal garden have hosted design week installations for several years, including COS’s own 2018 collaboration with Phillip K Smith III. Mamou-Mani read the building’s own geometry, its square coffering, diamond motifs and herringbone brickwork, and used it as the starting point for Conifera’s structural logic, computing each brick’s size and orientation from where it sat in relation to those existing patterns. That earlier installation, Open Sky, used angled, mirror-polished steel to fold the same courtyard’s sky into a single reflective ring, and is covered in full here.

Each bio-brick was a lattice of interlocking, truncated pyramidal forms, closer to a woven basket or a wasps’ nest than a conventional building block, and light enough that the whole structure had roughly the density of foam despite its total weight. The bricks connected to one another with simple PLA cable ties rather than mechanical fixings, which meant the entire installation could be taken apart as easily as it had been assembled.

The material told its own story in colour. Mamou-Mani used three finishes of the same PLA bioplastic: a fully translucent version in its purest state, a white pigmented version, and a warmer, wood-toned version made by adding pulp from fir trees, the same family of tree the installation was named for. Moving through the piece, a visitor passed from the dense, timber-coloured bricks nearest the palazzo’s stone colonnade to the clear, glass-like bricks further into the garden, a gradient Mamou-Mani described directly: “You have gradients of colour. We’re not obsessed with a uniform finish.”

The architect behind it

Arthur Mamou-Mani trained at the École nationale supérieure d’architecture de Paris-Malaquais before attending the Architectural Association in London. He founded Mamou-Mani Architects in 2011, and that same year began teaching Diploma Studio 10 at the University of Westminster alongside the architect and educator Toby Burgess, with whom he later co-founded the open teaching platform WeWantToLearn.net. His studio operates from a base in east London built around Fab.Pub, his own digital fabrication workshop, where large-format 3D printers sit alongside the design team rather than in a separate facility.

By 2019, Mamou-Mani was already known internationally for his large-scale, digitally fabricated structures, most prominently Galaxia, the temple he built for Burning Man in 2018. Galaxia was formed from 20 spiralling timber trusses converging on a 3D-printed mandala at its centre, a reference to the spiral of the Milky Way, and Mamou-Mani was the first non-American architect selected to design the festival’s temple. Burning Man’s temples are traditionally burned at the close of the festival, in a public ritual of release. Conifera, coming less than a year later, worked from the opposite instinct: rather than being destroyed in a single dramatic act, it was designed to be quietly decomposed once it was no longer needed. Both structures were built to disappear. The interesting part is that neither disappearance was an accident, and each said something different about what a temporary building can be for.

Mamou-Mani has been consistent about what he is trying to prove with this body of work, describing his broader ambition as wanting to show “that craftmanship can grow into large scale buildings” and to challenge “the idea that temporary, small scale structures are not architecture.” Of Conifera specifically, he said the aim was to “showcase how renewable materials, coupled with an algorithmic approach and distributed 3D printing, can create the building blocks of the future.” He has also been direct that the technology is only a means to an end: “Technology alone doesn’t really matter, it’s what you do with it, and to me it’s only interesting if we are helping the planet.”

How it was made

Conifera’s 700 bricks were not printed in a single workshop. Mamou-Mani’s team designed the geometry using open-source parametric software, generating a shared digital file that could be sent to multiple 3D printers at once, and had the bricks produced simultaneously across four fabrication sites: his own Fab.Pub in London, and three partner workshops in Italy, in Milan, Venice and Macerata. Each site printed from the same code, using Delta WASP 3MT industrial 3D printers built by the Italian additive manufacturing company WASP, so that a single design could be manufactured close to where its constituent parts were needed rather than shipped from one factory.

Individual bricks took between four and a half and seven hours to print, and the full run, alongside design and testing, took roughly two months. Each brick’s exact form, its density, its wall thickness, its degree of translucency, was generated by the same parametric logic that shaped the installation as a whole: a computational process that behaves less like a set of instructions and more like a growth rule, producing variation from a consistent underlying logic in something like the way a living structure would.

That approach connects Conifera to Mamou-Mani’s wider practice, in which parametric software (principally Rhino and Grasshopper) is used to let a form emerge from a set of parameters, material behaviour, structural load, environmental exposure, rather than being drawn first and tested afterwards. For a 2018 project he co-developed Silkworm, an open-source plug-in that converts Grasshopper geometry directly into 3D-printing toolpaths, allowing a print to vary its parameters as it goes rather than following a fixed, uniform path. Conifera used that same underlying philosophy: a structure computed, brick by brick, from the same rules that generated the whole.

The material at the centre of it all was PLA, or polylactic acid, made by fermenting renewable plant starch into a plastic that is industrially compostable at the end of its life. Once Milan Design Week ended on 14 April 2019, Conifera was disassembled and its bricks composted, closing the loop the installation had been built to demonstrate. In the years since, Mamou-Mani’s studio has kept pushing on where that PLA itself comes from, experimenting with feedstocks including potato and beetroot starch to shorten the supply chain further and reduce the distance the raw material has to travel before it becomes a building block.

COS and eight years of building something new

Conifera was COS’s eighth consecutive year building an installation for Milan Design Week, a run that started with the brand’s 2012 debut at the fair and has continued with a different architect, artist or designer each year since. In 2016 the brand worked with the Japanese architect Sou Fujimoto on a light-based installation; in 2017, with Studio Swine on a piece built around scent and mist; and in 2018, with the American light artist Phillip K Smith III on Open Sky, a mirrored installation staged in the same Palazzo Isimbardi courtyard Conifera would later occupy. That 2017 installation, Studio Swine’s New Spring, is covered in full on this site too, marking the point two years before Conifera where the same annual series began.

That pattern matters because it sets Conifera in context. COS’s Milan Design Week commissions have consistently gone to practitioners working at the edge of their discipline, people testing an idea about material, light or space rather than producing a conventional showpiece, and each year’s installation has stood on its own rather than repeating what came before. Mamou-Mani’s brief fitted that history precisely: a structure that treated 3D printing and bioplastic not as a novelty finish but as the entire proposition, built to be taken apart and returned to the ground once its six days in Milan were over.

What Conifera argued, and why it still matters

The easy way to describe Conifera is as a striking, photogenic object: a pale lattice threading through a Renaissance courtyard, built with a technology still novel enough in 2019 to be a story in itself. That description is accurate as far as it goes, but it misses what made the piece worth building.

Conifera’s real argument was about where a building’s parts come from and where they go afterwards. Distributing fabrication across four workshops in two countries, all reading from the same digital file, was Mamou-Mani’s way of demonstrating that a large structure does not need a single factory or a long supply chain; it can be grown, brick by brick, wherever the printers already are. Designing those same bricks to be composted rather than landfilled or stored was his way of demonstrating that a temporary structure’s ending can be as considered as its beginning.

Put those two facts together and Conifera reads less as a one-off show piece and more as a working prototype for an idea Mamou-Mani has spent his career refining: that architecture, at least at the scale of a pavilion, can behave like a living system, computed from a shared set of rules, manufactured close to where it is needed, and returned to the earth when its purpose is served. Milan Design Week gave that idea a stage large enough, and public enough, to be tested in full.

Final thoughts

It would be easy to file Conifera away as a striking piece of design week photography, the kind of installation that circulates for a season and is then remembered mainly for how it looked. What actually happened at Palazzo Isimbardi in April 2019 was more specific than that. Arthur Mamou-Mani used a fashion brand’s annual Milan commission to test two ideas at once: that a large structure can be manufactured close to where its parts are needed rather than shipped in, and that a temporary building can be designed to end as deliberately as it begins.

Conifera answered both. Four workshops in two countries printed from one file. Seven hundred bricks came down after six days and went back into the ground. COS’s eighth year at Milan Design Week produced its most direct demonstration yet of what a building could be if it behaved less like a permanent object and more like the tree it was named for: something that grows in response to its conditions, and gives back what it used.