Picking through a crate of reclaimed floor tiles, Micheal Ghyoot lifts out a square patterned in blue, gray and white with an art nouveau motif.
“These are easy to like, because they have this floral pattern,” said Ghyoot, a researcher in architectural reuse, holding the cement tile once common in many Belgian homes built in the early 20th century. “And, in the ’30s and ’40s, they started producing more modern patterns, and these are super interesting as well.”
The crate is one of dozens of boxes of tiles in varying styles, sizes and colors, all waiting to be cleaned and sorted for resale at Rotor DC, a Brussels-based cooperative that specializes in salvaged building materials.
In a nearby warehouse, tall solid wood doors with original handles stand along a wall beside large, gold-tinted windows rescued from a mid-century office building. Outside, a photographer arranges bathroom sinks on wet grass to shoot the online store catalogue.
Since opening a shop in a former office building in late 2016, Rotor DC has promoted the idea of urban mining in Brussels. Material scouts locate buildings slated for demolition and experts carefully remove anything that can be reused: Murano glass light fixtures, solid oak floorboards, handmade decorative brickwork and more.
Rotor is one of several such organisations in Belgium, and similar enterprises operate across Europe and North America. The practice is paired with research and guidance: Rotor’s design practice advises projects that want to integrate reclaimed components and publishes work on sustainability, circularity and the material economy.
Construction sector has a huge environmental footprint
Reusing building materials is not new—medieval builders often recycled pieces of Roman structures—but industrial mass production and modern procurement systems moved construction toward new materials. Today the whole construction ecosystem—procurement, liability, regulation, scheduling, insurance and standards—has been built around new products, making direct component reuse (windows, doors, beams, facades, sanitary fixtures, flooring) less common than lower-grade recycling or downcycling.
“Direct component reuse in original form… is still less widespread than lower-grade recycling or downcycling,” said Areti Markopoulou, academic director at the Institute for Advanced Architecture of Catalonia. She noted reuse faces practical hurdles: careful deconstruction, storage, certification and the problem of matching a sporadic supply of salvaged items to projects that need them.
“We know how to crush buildings very efficiently, but we are still learning how to disassemble them intelligently,” Markopoulou added.
Most demolition waste ends up as backfill or ground cover, if it’s reused at all. Construction and demolition waste account for more than a third of all trash in the European Union. The building sector also consumes large shares of extracted materials—around half in the EU—and associated greenhouse gas emissions are estimated at roughly 5% to 12% of national totals.
“Reuse matters not only because it diverts waste, but because it can avoid the emissions associated with producing new materials altogether,” Markopoulou said.
A 2019 report by the Ellen MacArthur Foundation argued that reusing materials such as steel, aluminium, concrete and plastic could reduce demand for new products and that circular economy strategies could cut global building-sector emissions by up to 40% by 2050.
Reuse gaining ground, but still niche
Ghyoot said persuading contractors and architects to use secondhand materials is not straightforward. Changing design and construction workflows can add complexity and cost, and reclaimed supplies are rarely consistent. Older components may be degraded, contain toxic substances, or be difficult to remove intact.
“You have to rethink how you design, how you organize the workflow, how you work with builders,” said Ghyoot, who is also a project manager at Rotor. “We do our best to facilitate that. But it remains a bit of a niche practice overall in the construction industry.”
Initially Rotor DC handled most deconstruction and preparation work itself. Over time it introduced a buyback system for reclaimed elements, purchasing material from private sellers and especially from contractors and demolition crews.
“What we found out is that it was not a matter of skill from their side—they usually know how to do that properly,” Ghyoot said. “But if you bring a bit of money into the mix, then they are ready to [put in] the effort because there is something in it for them.”
AI, digital tools can support material recovery
Markopoulou and colleagues are exploring how digital tools and artificial intelligence could improve recovery of valuable reusable components—solid timber, stone, steel and brick—from demolition projects. Their approach treats cities as huge material reservoirs and uses data sources such as Google Street View, aerial imagery, 3D scans, cadastral records and permits to estimate what materials are contained in buildings, when they might become available and in what quantities.
The method has been tested in cities including Barcelona, New Delhi, Helsinki and Singapore. “We cannot yet predict every reusable window or beam, but we can already estimate urban material stocks well enough to plan for reuse at city scale,” Markopoulou said. “AI can’t tell you everything inside a building, but it can radically improve how we predict urban material stocks before demolition or renovation even starts.”
She said these digital capabilities will need policy support. Mandatory energy performance certificates have already nudged construction toward sustainability; material and building passports—which record detailed information about the elements that make up a structure—could help plan for reuse and shift how buildings are conceived.
“It’s a change of mentality, because buildings were always thought to be permanent,” Markopoulou said. “We need to design while taking into consideration where our materials will go after the lifespan of the building is over.”
Edited by: Tamsin Walker