Material waste is one of the most difficult factors to control in construction projects of all sizes. The Environmental Protection Agency (EPA) found that total waste from construction-related projects was double that of municipal waste from households and businesses. For sustainable construction, the biggest issue is waste handling, since the construction industry requires more natural sources and energy.
With the increase in urbanization, construction and demolition waste (CDW) has many side effects, the worst being environmental degradation. The amount of CDW in urban areas is still unknown. ‘You can’t improve what you cannot measure’ is the case with construction waste. We do know that demolition represents 90% of the CDW while construction represents only 10% of total CDW (EPA, 2019).
Here are the biggest culprits of material construction waste:
- Concrete: which makes up over 65% of CW
- Ceramic, tile and glass
- Insulation Materials
- Ferrous Metal
- Non Ferrous Metal
- Stone and Clay
Is it too late to dig ourselves out of this landfill?
Many experts say no, but they do agree, the problem is still getting worse rather than better.
Here are some statistics on construction waste that might cause you to pause the next time you see a landfill:
- 23% of the national waste stream is estimated to be CD waste.
- The U.S. generated over 600 million tons of construction-related waste in 2018.
- CDW waste generation in the U.S. increased by 342% from 1990 to 2018.
- As much as 30% of all building materials delivered to a typical construction site can end up as waste.
- More than 75% of all construction waste from wood, drywall, asphalt shingles, bricks and clay tiles ends up in landfills.
- Concrete and asphalt concrete made up 85% of all U.S. CD waste in 2018. (EPA)
As mentioned above, demolition projects contribute significantly more waste than new construction projects. Buildings can be demolished in several ways, but some ways are more prone to material recycling than others.
These building demolition statistics show just how destructive the process can be:
- In 2018 alone, demolitions added 567 million tons of debris to the national waste stream.
- Demolition of roads and bridges accounted for 43% more debris than building demolition in 2015.
- A 2016 study found that among more than 50,000 analyzed demolitions, nearly half were to make way for new construction.
- Concrete has one of the longest useful lives among building materials, but concrete structures account for the most demolition projects by far.
There isn’t a universal solution to solving the construction waste problem but many construction firms are finding innovative ways to reduce their contribution to the pileup. Adaptive reuse projects result in a more positive environmental and social impact than building demolitions. Lean construction and value engineering target waste in the planning stages, while post-planning construction services provide waste removal, recycling, and disposal solutions.
Not all countries approach their waste management efforts in the same way.
In the United Kingdom it is legally required to properly manage it and confirm that it’s following a waste management hierarchy. This is crucial in order to help minimize the environmental impact and reduce the demands placed on their landfills.
According to government statistics, in 2018 construction and demolition businesses in the UK generated 67.8 million tonnes of non-hazardous waste. However, 62.6 million tonnes of this was recovered, equating to a recovery rate of 92.3%. This means that, despite the UK’s high output of non-hazardous waste from construction and demolition, our reuse and recycling processes are overall positive.
The European Waste Catalogue (EWC), sometimes referred to as LoW (List of Waste), lists all the different types of waste with classification codes. Materials listed included the ones you would expect such as concrete, wood, metal and bricks but there are a number of waste materials that might surprise you. A few examples are paper, cardboard, glass, plastic packaging, soil and stone. There are detailed guidelines for each category that include classification, labeling, handling and reuse instructions.
Some countries trade waste products like commodities and the recycling and recovery process can generate thousands of jobs. Using the United Kingdom example once again, they export several thousand tons of waste every year, but the country recycles nearly 90% of CD waste.
Corporate Values and Priorities
It is vital for management at the organizational level to identify waste at the project level. This should be built into business practices and the priorities of building owners and general contractors. The organization level provisions are often communicated through policy statements and work plans. It is important to measure the performance in the field against corporate targets for diversion, reduction, reuse and sustainability green building practices. Organizations can work with vendors responsible at the disposition level to ensure that business practices and operation of segregation, sorting, transporting and final disposition of waste meet or exceed corporate expectations.
Common Materials Recycling Practices and Uses
- Ferrous and non-ferrous metals are among the most valuable materials in the construction and demolition waste stream and consistently demonstrate the highest diversion rate of all the recoverable materials.
- Post-consumer plastics can be valuable commodities. Generally plastics are not recycled into material of the same type and grade (downcycled). Plastic may also be granulated or chopped into flakes and placed in industrial tote bags for transport.
- Wood is a valuable commodity and merits diversion. It is highly useful in a wide variety of industrial processes including manufacturing of high recycled content products.
- Concrete is crushed, and embedded metals removed for recycling. Rock and cement pieces are crushed, screened and separated to produce useful aggregates of various dimensions.
- Window glass is a nuisance material with a nominal value as a recyclable commodity. Its relatively high weight per volume is a factor in restricting economical transport. Window glass usually ends up in a landfill unless a recycler is located in the vicinity of the diversion facility.
- Drywall is 100% recyclable. Gypsum is a nuisance material in picking and sorting operations, producing dust which discomforts labor, and reduces the value of recyclable materials through contamination. Gypsum may be incorporated into new drywall, or used as a soil amendment.
- Asphalt roofing shingles may be ground, sized and graded for remelting in asphalt paving applications, road base, new roofing, and fuel oil.
- Doors, windows, and hardware often have value in a secondary market when one is available.
There is a lot of treasure to behold among all the trash and debris. Recycling is responsible for more than 85% of waste management jobs despite the fact that the U.S. recycles only a third of its total waste output.
Here are some positive recycled construction materials statistics:
- New construction contributed just 5.5% of all U.S. Construction waste in 2018.
- In 2018, 76% of all CDW in the U.S. was recovered or recycled.
- Over 95% of concrete and asphalt concrete waste was recovered in 2018.
- A 2016 study showed that in one year alone, CDW recycling opportunities led to the creation of 175,000 U.S. jobs.
- 98% of steel in construction and demolition projects is recycled to new uses.
- Jobs created by recycling and reuse outnumber traditional waste disposal jobs 9-to-1.
- Recycling efforts can reduce U.S. landfill expansion by 1,000 acres for every 135 million tons of waste recovered.
Although the construction industry contributes a quarter of the country’s annual waste generation, the industry is already doing an incredible job of recovering building materials. By using recycled materials and smart asset management systems, and by avoiding demolition projects via adaptive reuse, construction companies are making large strides toward zero waste.
Waste reduction practices are applicable to virtually any construction and demolition project scenario. The goal is to divert materials from landfill disposal to the greatest extent practical under the circumstances. As with any construction project, planning and project management will ultimately dictate whether waste reduction is accomplished within the established cost, schedule, and quality guidelines.
The major uncertainty is usually the availability of salvage and recycling services and outlets, and any costs associated with handling these materials. Resources are available to help owners and contractors familiarize themselves with the salvage, reuse, and recycling industries and infrastructure.
This is one helpful resource: https://www.wbdg.org/design-objectives/sustainable/optimize-building-space-material-use
In an era of ever increasing energy and material prices, construction and demolition waste will become more widely recognized as a recoverable resource. Technology and regulations will drive improvements in the diversion of wastes from the landfill and increasingly toward energy generation and recycling of materials.
Industrial recycling equipment manufacturers are investing in the development of improved machinery which has potential to revolutionize the efficient sorting and diversion of waste. Public attention to issues of indiscriminate dumping of wastes will continue to pressure governments to ensure compliance with environmental regulations.
The Digital World is Taking Action
Artificial intelligence (AI) can make a significant difference in construction waste levels.
In one project, researchers used records from 2,280 building demolition projects to train an algorithm that could predict the total value of materials recovered from a destroyed building with a 97% average accuracy. The researchers’ results could improve waste reduction efforts, particularly as construction professionals perform pre-demolition audits.
Some applications of AI in construction waste reduction happen off the construction site. A recently developed sorting robot uses AI to differentiate among various kinds of construction and demolition waste.
Building Information Modeling (BIM) software allows companies to monitor supply chains and make recovery and recycling plans for materials during construction and can be applied to demolition as well. Viewing the potential outcomes through 3D fashions and adjusting accordingly can save money and time, plus reduce labor and material waste.
BlockChain will play a role!
There are immediate benefits to the construction industry that Blockchain Technology provides which can be directed toward reducing waste.
- Predictive asset maintenance
- Smart contracts for added accountability
- Proactive third-party oversight
- Instantaneous collaboration
- Streamlined supply chains
DigiBuild is a blockchain-enabled construction project management platform. Our customers manage workflows such as procurement, budgets, schedules, contracts, and payments. DigiBuild allows for collaboration across 50+ disparate construction stakeholders – all on a single platform.
We are the first to merge our construction management expertise with blockchain technology to create the world’s most revolutionary technology bringing risk management and visibility to your projects.
Through verifiable collaboration, we eliminate risk, disputes, save time and create a healthier and happier global construction industry.