Picking through a crate of reclaimed floor tiles, Micheal Ghyoot pulls out a square cement model with a blue, gray and white art nouveau motif.
“These are easy to like, because they have this floral pattern,” said Ghyoot, a researcher in architectural reuse, holding a tile that was common in many Belgian homes 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 containing tiles of many styles, sizes and colours, all waiting to be cleaned and sorted for resale at Rotor DC, a Brussels cooperative that specialises 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. Outside, a photographer arranges bathroom sinks on wet grass to shoot items for the online store.
Since opening a shop in a former office building in late 2016, Rotor DC has pushed the idea of urban mining in Brussels. Material scouts locate buildings slated for demolition and experts rescue anything reusable — from Murano glass light fittings to oak flooring and handmade brickwork.
Rotor is one of several such organisations in Belgium, and similar operations exist across Europe and North America. The practice also extends beyond resale: Rotor’s design practice advises projects that want to incorporate reclaimed components and publishes research on sustainability, circularity and the material economy.
Construction sector has a huge environmental footprint
Reusing building materials is not new — medieval builders often incorporated elements of older Roman structures — but industrialisation and modern manufacturing shifted the sector toward new products. “The whole construction system — procurement, liability, regulation, scheduling, insurance, standards — was built around new materials,” said Areti Markopoulou, academic director at the Institute for Advanced Architecture of Catalonia. She added that direct component reuse — windows, doors, beams, façade elements, sanitary fittings, flooring — remains less common than lower-grade recycling or downcycling.
Practical barriers are many: deconstructing buildings carefully, storing rescued parts, certifying reused items and aligning irregular supplies with new projects. “We know how to crush buildings very efficiently, but we are still learning how to disassemble them intelligently,” Markopoulou said.
Because of that, much demolition waste is crushed and used as backfill or ground cover instead of being reused. Construction and demolition waste accounts for more than a third of all EU rubbish. The focus on new materials carries a major environmental cost: the building sector consumes around half of all extracted materials in the EU, and associated greenhouse gas emissions are estimated at 5–12% 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 noted that reusing materials such as steel, aluminium, concrete and plastic would reduce demand for virgin products. Shifting to circular-economy strategies could cut the global building sector’s emissions by as much as 40% by 2050.
Reuse gaining ground, but still niche
Ghyoot said persuading contractors and architects to adopt secondhand materials is not straightforward. Change takes time, can raise costs, and salvaged items don’t guarantee a consistent supply of identical products. Older materials can be degraded, contain toxins or be hard to dismantle. “You have to rethink how you design, how you organise 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.”
At first, Rotor DC handled all salvage and preparation work itself. That shifted when the cooperative started buying reclaimed elements back from private sellers and, importantly, from general contractors and demolition teams. “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 her team are exploring how digital tools and artificial intelligence could boost recovery of reusable components like timber, stone, steel and brick. “Cities are enormous material reservoirs,” she said. The approach uses sources such as Google Street View, aerial imagery, 3D scans, cadastral records and permit data to estimate what materials and components are likely present in buildings, when they might become available and in what quantities.
The research has been piloted 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 emphasised that digital tools and financial incentives need policy support. Measures such as mandatory energy certificates can push construction toward sustainability, while material and building passports — detailed records of a structure’s components — would help plan for reuse and change how buildings are designed. “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