Reusing materials in architecture

When One's Waste Brings Joy to Others

Every year, the construction industry discards 250 million tons of waste. This sector alone accounts for 70% of France's annual waste production. However, amidst this situation, there are solutions, and new actors, both virtuous and responsible, are striving to establish a new paradigm. While many worry about the tons of unutilized waste, advocates of reusing materials seek to raise awareness by promoting new practices, turning yesterday's constructions into the building blocks of tomorrow.

Is reusing materials an age-old solution to meet the challenges of the future? Among government authorities, project managers, and developers, digital marketplaces are eager to take the lead in this transformation.

From Waste Bins to Online Platforms

How can one make money from waste? This question is a daily concern for Sébastien Duprat and Lucile Hamon. Each of them found their own answers - Cycle Up and Backacia, respectively. What do they have in common? They launched digital platforms dedicated to the valorization of waste from deconstruction sites. "Our primary goal is to place the circular economy at the heart of an economic solution," says Lucile, the founder of Backacia, a platform for buying and selling reclaimed materials.

Sébastien, founder of Cycle Up, aims to match the abundant supply of available and reusable materials with the demand. However, don't call him a pioneer: "The construction industry has been doing this forever! The Lilles-Flandres Station, inaugurated in 1846, is none other than the former Gare du Nord, dismantled and rebuilt stone by stone!"

"The Demolishers are Top Gun of Building Engineering!"

Ecological, responsible, and practical on paper, reusing materials remains obscure and underused in practice. The challenge lies in adapting reuse to modern construction. According to Sébastien Duprat, the professionals at the forefront are already showing the way. In late 2018, he organized a consultation for a deconstruction project, following a specification facilitating reuse. However, there was little enthusiasm from curators and demolishers, and the entrepreneur faced exorbitant proposals. But this obstacle quickly transformed into a reason for optimism: "12 months later, we tried again. The result: 3 proposals with clear and detailed methodologies and no additional costs!"

For the founder of Cycle-Up, this adaptation shows that a well-structured reuse industry can be beneficial to all: "Today, the cost of processing one ton of waste is around 200 euros! Everyone is interested in a solution." In this context, the argument in favor of reuse is compelling: saving money instead of spending it. Consequently, today, project developers and companies are finding a balance that suits them.

Calculating the Reuse Share in Your Project

The weight of the building, obtained during a Life Cycle Assessment (LCA) study, determines the percentage of reused materials. Cycle-Up offers a methodology for this, which can be found at this link.

Architecture and Diagnosis

"For me, reuse has given meaning to my approach to architecture," explains Morgan Moinet, an architect and head of Remix, a specialized study bureau integrated into the agency "Encore Heureux." For him, the approach revolves around several axes: study, assistance to project owners, and training. Architects, more than ever, must accompany each stage of a building's life, often starting with its end: "Identifying a resource reservoir is the first step. This requires a resource diagnosis," he explains.

In simpler terms, this means identifying the materials that can be extracted and their potential for reuse. In this regard, the law has evolved, and the new version of the waste diagnosis, now called "products, materials, and waste" diagnosis, implemented since January 1, 2022, aims to facilitate the generalization of reuse.
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Starting Reuse in Your Project: Where to Begin?

Adjusting the Project Timeline

One challenge remains: aligning construction and deconstruction. In this period, which can last for months or even years, platforms face the thorny question of material availability.

At Backacia, the teams work hard to synchronize schedules so that reusable materials are available when they can be transferred to the construction project.

At Cycle Up, they prefer to talk about the "BAMB" - the Building As a Material Bank. This concept involves using a building, still standing, as a source of materials for the future, 2 or 3 years down the line.

The benefits: bidding farewell to the costs of guarding or storing materials, and avoiding the risk of being stuck with unwanted raw materials.

Who Is to Blame?

At this point, an architect may listen attentively to the arguments for reuse, but they may also raise additional concerns and responsibilities that they will likely reject. When a product is new, the manufacturer's responsibility protects it. But when it is no longer new, who will the project owner turn to in case of a problem?

For Lucile Hamon, the solution is to exclude materials whose use requires a specific standard. Goodbye, then, to the fire-resistant door that loses its certification when taken off its hinges, and hello to carpets and other coverings that do not require any specific guarantees.

At Cycle Up, they draw inspiration from other sectors: "No one is surprised that you can insure a used car. Why should it be any different for a brick?"

Just as the Unified Technical Documents (DTU) do not specify whether materials used in construction should be new or not, the use of a specialized marketplace for reuse should not, according to Sébastien Durat, change anything.

For Morgan Moinet, nothing is set in stone, and it will all depend on how the industry adapts. "Today, one of the main challenges of reuse concerns inert materials. But some possibilities are emerging. Tests are being carried out on the cutting of large reusable concrete sails. Why not produce paving stones with this concrete? The possibilities are numerous."

FOR MORE INFORMATION
‍Read the book "Matière Grise": consume more "gray matter" to consume fewer "raw materials" – one of the main themes of this book, which summons collective intelligence to reconsider our use of materials in architecture. 14 essays, 13 interviews, and 75 projects demonstrate the potential of reuse and the possibility of a new life for worn materials in all aspects of building.
‍-> Order "Matière Grise"

The blog "materiauxreemploi.com": a website dedicated to the latest news about the reuse of construction materials in architecture. Managed by the REMIX study bureau, the site aims to disseminate the practices of actors involved in the reuse of construction materials to as many people as possible. It was created in early 2018 by Morgan Moinet, who is still its editor-in-chief today, to perpetuate, disseminate, and extend the research of the "Réemploi des matériaux de construction" watch group, which now has over 8000 members.