The U.S. construction industry is among the world’s largest polluters and consumers of energy and resources. As economic forces and cheaper, less durable materials have incentivized razing structures rather than repurposing them or salvaging construction materials, the industry’s production of construction waste skyrocketed to 600 million tons by 2018, an increase of more than 300% since 1990. And as new buildings spring up, so too does their contribution to greenhouse gas emissions — which reached a new high in 2023.
Efforts to reduce waste, encourage remodeling and reuse of buildings and implement energy efficient design practices often run up against the reality of deadlines, budgets and shifting priorities. But at a moment when new digital technology is promising greater productivity, could it also be harnessed to make our economy less wasteful?
A group of researchers from Drexel’s College of Engineering recently examined how these technologies, including machine learning, AI, blockchain, and various augumented reality and Internet of Things technologies, are being used to reduce waste and the carbon footprint of the construction sector. Their study, “Digital Technolgies and Circular Economy in the Construction Sector: A Review of Lifecycle Applications, Ineggrations, Potential, and Limitations,” which was published in the journal buildings, highlights the challenges and potential of integrating these new technologies into design and building processes.Fernanda Cruz Rios, PhD, an assistant professor in College of Engineering, who studies environmental sustainability in the built environment and was a co-author of the study, recently shared her insights with the Drexel News Blog about the state of the construction sector and the technology that could help it build a more sustainable future.
First off, can you explain the concept of circular economy any why it’s important for improving sustainability?
The circular economy is a more sustainable way of managing resources compared to the traditional “take-make-waste” system, where we extract raw materials, use them for a short time, and then throw them away. As consumer demand grows, this wasteful cycle has led to resource depletion, pollution and environmental damage.
But the impact isn’t just environmental — it’s also a social justice issue. Many of the materials we use, like metals and timber, are extracted in developing countries, often under harsh working conditions, while wealthier nations benefit from the final products. To make matters worse, much of the waste generated in these wealthy countries is shipped back to poorer regions, offloading the environmental burden. Even in the U.S., landfills, incinerators and mining operations are often placed near low-income communities and communities of color, increasing their exposure to pollution and long-term health risks.
The concept of a circular economy calls for breaking this cycle by keeping materials in use for as long as possible through reuse, repair and remanufacturing. Instead of throwing materials away, they are recycled into equally valuable products, reducing the need to extract more raw materials.
This approach doesn’t just help the environment — it also makes economies more resilient. Recent global supply chain disruptions have shown that relying on imported materials can lead to shortages and price spikes. Circular strategies, like urban mining (i.e., sourcing reusable materials from existing buildings instead of virgin resources), local material reuse and manufacturing products with recycled materials, help reduce dependence on unstable global supply chains and encourage self-sufficiency. At the same time, the circular economy would create new job opportunities in areas like repair, remanufacturing and building deconstruction. If implemented correctly, the circular economy can lead to a more sustainable and fairer economic system.
How has the construction industry evolved to become more wasteful and less sustainable over the years?
Many of the innovations that make modern life more comfortable — like new building materials, air conditioning, and global trade — have also made construction more wasteful.
In the past, buildings were designed to last for generations, but today, the industry prioritizes fast, low-cost construction over durability. This has led to an increase in waste and resource consumption, as cheap materials like drywall, plastics, and synthetic insulation wear out quickly and need to be replaced more often.
The reliance on mass-produced, imported materials has also disrupted local supply chains, increased carbon emissions from transportation and left the industry vulnerable to supply chain disruptions and price fluctuations.
On top of that, modern buildings depend heavily on artificial lighting and mechanical systems, rather than taking advantage of natural ventilation, daylight and passive design strategies that could reduce energy use and carbon emissions. Keeping these buildings climate-controlled requires constant energy input, further increasing resource consumption and emissions.
This shift toward disposable buildings and inefficient material use is putting massive strain on natural resources, while also increasing environmental and economic risks. To create a more sustainable and resilient future, the construction industry needs to return to circular, locally sourced and adaptable design strategies, while embracing passive design to reduce reliance on artificial systems.
How might a digital technology, like blockchain or “material passports,” incentivize the use of more sustainable building materials?
Digital technologies, like blockchain and material passports, are still in their infancy but promise to incentivize sustainable building materials by increasing traceability, transparency and market confidence.
A material passport is a digital record that stores information about a building material’s properties, origin and reuse potential. Think of it like a “nutrition label” for construction materials, but instead of listing calories and vitamins, it includes details like what the material is made of, how long it lasts, whether it can be recycled or reused and where it has been used before.
Material passports help make sustainable construction easier by keeping track of materials throughout a building’s life. When a building is renovated or demolished, the passport tells architects and contractors which materials can be recovered and reused instead of being thrown away. This reduces waste, lowers demand for new raw materials and cuts down on carbon emissions.
When combined with digital tools like blockchain or Building Information Modeling (BIM), material passports can also help create a marketplace for reclaimed materials, making it easier for the industry to transition to a circular economy, where materials are continuously reused instead of being discarded.
Artificial intelligence is already having an impact on so many fields, how might it contribute to more sustainable design practices?
Artificial intelligence can transform sustainable design in construction by making buildings more efficient, adaptable and “circular” — or easier to deconstruct for component reuse. AI can analyze massive amounts of data to optimize building layouts, material choices, and energy use, helping architects and engineers design greener buildings from early design phases and rely less on circular economy expert knowledge.
For example, machine learning algorithms can predict which building materials will last longer or be easier to reuse. AI can also help identify, quantify, and categorize the amount of building materials that are currently in use within cities and infrastructure, which can later be recovered, reused, or recycled instead of being wasted when buildings are renovated or demolished. In fact, we are working on it right now at Drexel’s CIRCLE lab.
AI is also being used to track materials throughout a building’s life cycle, ensuring that valuable resources do not end up in landfills. By integrating AI with Building Information Modeling (BIM) and material passports, designers can make informed decisions about reusing components in future projects. AI-driven image recognition and robotics can even help sort demolition waste, making recycling more efficient. Ultimately, AI makes sustainable and circular design more practical and scalable, helping the construction industry move toward a smarter, less wasteful future.
What are some techniques that we could be using right now to help recover and reuse building materials?
Right now, we can deconstruct buildings instead of demolishing them, which allows materials like wood, brick and steel to be recovered and reused instead of being sent to landfills.
Several U.S. cities have already adopted deconstruction ordinances to reduce waste and promote material reuse. Portland, Milwaukee, San Antonio and Palo Alto, California all require deconstruction for certain older buildings (Palo Alto requires deconstruction of all buildings!). Our neighbors in Pittsburgh also introduced a deconstruction policy aimed at salvaging materials from condemned structures to reduce landfill waste and promote sustainability. Mayor Bill Peduto signed an executive order to pilot deconstruction on city-owned properties, focusing on recovering materials like bricks, tiles and woodwork for reuse in other projects. In Philadelphia, local organizations like Circular Philadelphia are trying to push for local policies to incentivize deconstruction and material recovery.
What are the primary impediments to taking steps to standardize sustainable practices in design and construction?
Although there are a few technical and technological barriers, most of the impediments to creating more circular buildings and cities lie in policy, awareness, and human behavior. Existing building codes often fail to support material reuse, salvage, and design for disassembly (often for safety reasons, which leads to a need to improve building materials’ testing before reuse). Without clear regulations or incentives, developers and contractors have little reason to adopt sustainable practices, and low landfill fees make demolition and disposal much cheaper than recovering materials for reuse or recycling.
Education and awareness gaps also slow progress. Many architects, engineers, and contractors lack training on circular economy principles, leading to skepticism about material reuse and hesitation to deviate from conventional methods. The construction industry is traditionally risk-averse, and without widespread knowledge of circular strategies, professionals default to linear, waste-heavy practices.
Some behavioral barriers are also worth mentioning (they are my favorite because we often don’t talk about them in engineering). Many architects resist designing for disassembly, associating it with temporary or low-quality construction rather than long-term resilience. Even ego gets in the way! Architects do not like to think of their buildings being changed or deconstructed. There is also widespread confusion between toughness and adaptability — many in the industry equate durable buildings with those that are rigid and permanent, rather than those designed for flexible use and material recovery. Additionally, negative perceptions of salvaged materials, often viewed as lower quality or aesthetically undesirable, discourage their use. Shifting this mindset requires stronger policies, financial incentives, and the integration of circular economy principles into education and professional training.
Reporters interested in speaking with Cruz Rios should contact Britt Faulstick, executive director, News & Media Relations, at bef29@drexel.edu or 215.796.5161.
