Turning demolition waste into tomorrow’s resources.
By Rose Morrison, managing editor of Renovated and The Landscape Guide.
The practice of urban mining has encouraged sustainability-minded people to think differently about sourcing construction materials. Instead of extracting resources from the planet, this process reuses materials that people would otherwise discard.
Sometimes, it involves selective deconstruction, where teams strategically dismantle buildings slated for demolition and prioritize the most valuable aspects to reuse. In other cases, architects, construction leaders and other professionals examine the most effective ways to incorporate reused materials into projects rather than sourcing new ones. How have people applied these options, and why does it matter?
Applying Responsible Deconstruction Techniques to Historical Buildings
Building preservation specialists perpetuate the circular economy by viewing demolition as a last resort. Some of these professionals have dedicated their careers to preserving historically significant structures. Standing in a room that existed during the Civil War or a home where a baroque-period composer created a famous concerto are experiences that bring history to life.
However, keeping those older buildings safe is not always possible, especially if natural disasters or other unexpected events cause considerable damage to structures not originally built to handle them. In those cases, thoughtful deconstruction can allow some of the materials to live on in new projects.
Preserving History Through Generations
Re:Purpose Savannah is a Georgia-based organization focusing on mindful deconstruction techniques that source usable materials from historical homes. It has an 8,000-square-foot warehouse used to store salvaged materials, eventually sold to contractors and other entities working to preserve homes with historical significance.
Katie Fitzhugh, director of deconstruction, explained how those parties benefit from these resources. “They all use reclaimed materials in their restorations, rehabs and preservation projects. And that’s a really cool example of a true circular economy — we take out the materials, they buy the materials and they go back into historic homes in Savannah or any home in Savannah.” This approach has allowed the organization to recycle and salvage thousands of tons of material since 2018.
While this nonprofit focuses on climate-conscious alternatives to traditional methods of destroying buildings that are no longer suitable for use, the results sometimes have extremely personal impacts.
Such was the case with Mama Lizzie’s House. Located in Savannah’s Coffee Bluff neighborhood, it was named for the late matriarch of a family that had lived in the community for decades. Her daughter Mary hired Re:Purpose Savannah for a necessary residence-removal project while experiencing the emotional pain of releasing the structure to the past. Teams gently deconstructed and reclaimed all suitable materials, which Mary will use in a future home. Then, a local recycling partner handled everything that was not appropriate for reuse.
Statistics indicate the U.S. construction and demolition sector creates approximately 600 million tons of debris annually. This example reveals compelling ways to reduce waste, honor the past and prepare for the future.
Creating Resilient Buildings While Reducing Waste
As more areas of the world deal with increasingly severe weather, construction industry professionals search for effective ways to make structures more tolerant to harsh conditions. Some have also prioritized building-material harvesting options, such as turning materials from destroyed structures into reuse opportunities. Such approaches emphasize sustainability while addressing supply chain bottlenecks due to prolonged shortages.
Combining 3D Printing and Recycled Concrete
Marat Oshakhtiev lives in Almaty, Kazakhstan, a city with high seismic activity. While observing an ongoing cycle of destruction and rebuilding caused by frequent earthquakes, he used technology to pursue sustainable urban development. More specifically, he works at a company that uses construction material recycling to generate materials for 3D-printed homes.
This approach creates them in less than two months to specifications that account for earthquakes and the country’s extreme temperature variability. It’s also ideal for families that urgently need new homes after natural disasters.
These efforts led to the first 3D-printed house in Central Asia, highlighting a viable and new possibility for efficiently built and purposeful structures that keep usable materials out of landfills. Though 3D printers usually require special mixes when used to build homes, this team tweaked the process to use locally produced recycled material.
The specialty process includes a mobile crushing plant and magnetic separator to reuse waste concrete and the metals that reinforce it. Portable equipment to break up materials usually has a smaller carbon footprint than conventional options. That setup fits the group’s eco-friendly goals and helps them prepare the mixture closer to building sites. Optimized printing workflows reduce idle time and emissions, ensuring energy-efficient fabrication.
Oshakhtiev received funding from the Fostering Productive Innovation Project, a World Bank-financed program that enables inventions to solve economic and social challenges. He credited that initiative for giving his work the necessary momentum.
“Embracing modern technologies is essential in today’s world. With the World Bank support, we are staying at the forefront of technological advancements with 3D construction printing within our country. With this project, our company has confidently stepped into the future, addressing Kazakhstan’s urgent need for earthquake-resistant, modernized, efficient and resilient housing solutions,” he said.
Normalizing Urban Mining Through Forward-Thinking Decisions
Even as people develop and implement urban mining projects worldwide, some decision-makers are reluctant to change, preferring to adhere to what’s familiar even if they recognize it’s unsustainable. However, some authorities have overcome that hesitation by mandating new ways of doing things that prevent unnecessary waste.
Affected parties know they must comply to avoid fines, negative reputations and other undesirable outcomes. While these requirements may necessitate process changes and other organizational shifts, their long-term benefits reveal new possibilities that are better for the planet.
Following the Lead of Belgian Authorities
Brussels has emerged at the forefront of urban mining, largely due to a rule that requires demolition companies to create robust plans for extracting useful materials before destroying buildings.
A good example comes from the Multi project, which refurbished a tower built in 1969. Though it was once solely an office building, its current uses are more diverse and include housing, commercial units and workspaces. This effort is notable because it was the first renovation project to receive a material passport. It contains details to help people successfully dismantle the building and reclaim usable materials later.
Construction leaders frequently decide to demolish buildings and start from scratch. However, this project emphasized renovation, which maintained the existing building’s footprint and didn’t require submitting new planning permission documents.
The architects wanted to increase the usable floor space by widening each tower by just under 10 feet per side and building two more stories into each. That approach retained proportions while making the structure more suitable for new needs.
Focusing on reuse meant that 87% of the materials used in this project came from the original tower. Decision-makers also sourced another 3% from urban mining marketplaces that help users find viable materials from other deconstruction efforts.
Frederik Jacobs is the CEO and co-founder of Conix RDBM Architects, which handled the architectural design. He explained the design team’s conclusion that “…this building lent itself well to an intervention that preserved as much of the existing material as possible, allowing the right balance between what can be reused and the new elements that need to be brought in, and thus taking reuse a step further.”
Showcasing Urban Mining’s Viability
Taking usable products from old structures and using them in new construction is still relatively new. However, initiatives to highlight the possibilities could encourage leaders to consider them and update their knowledge to reflect the relevant commercial items and methods.
Spotlighting Options for South Africa’s Residences
A recent example of valuable support comes from a South African government program that funds circular economy projects before they achieve large-scale impacts. One project centered on subsidized housing and culminated in a demonstration house built with sustainable bricks by representatives from two companies who collaborated to create prototypes.
Each recyclable interlocking block contains 70% recycled content sourced from building rubble, waste glass and other suitable materials. The block design saves resources because it does not require cement between layers.
Additionally, people with limited experience can build or deconstruct the relevant structures, which is particularly valuable for areas grappling with labor shortages. For example, relatively unskilled workers assembled a demonstration home’s top structure — from the foundation to the roof — in only a week.
The blocks have strategically placed hollow areas, simplifying the installation of plumbing and electrical systems by creating channels when stacked. This approach prevents tradespeople from needing to cut grooves into the bricks as they work.
Workers on this project also wanted to incorporate waste glass into the bricks after realizing the unsustainable margins for transporting it from the local area to recycling facilities. That issue resulted in many people within the community discarding the material. This pioneering problem-solving method provides a favorable alternative to conventional virgin materials.
Urban Mining’s Multifaceted Benefits
These promising examples highlight how people can address several construction challenges with urban mining. Their commitment to this practice reduces demolition waste and eases material shortages. Even engineered infrastructure solutions are embracing this approach.
According to GeoQuest USA, a leader in mechanically stabilized earth (MSE) retaining wall systems, crushed concrete, and other recycled materials can be successfully used as select backfill in engineered wall structures. This reuse of materials shows how recycled construction materials aren’t limited to architectural elements. They can also serve critical structural functions in urban infrastructure projects. The recycled materials decrease the need for virgin aggregates and serve as another way for construction waste to reenter the building cycle — all without compromising quality.
Decision-makers interested in this approach should review the possibilities above by working with their peers to learn more about the best approaches based on their typical projects. Additionally, identifying organizations specializing in selective deconstruction could connect parties with reputable resources for the desired materials.
About the Author
Rose is the managing editor of Renovated and has been writing in the construction, landscaping and sustainable building sectors for over six years. She’s most passionate about improving environments, reducing carbon footprints and incorporating resourceful methods to promote well-being in the planet. For more from Rose, you can follow her on Twitter and connect on LinkedIn.