There is growing interest in practicing “Green Demolition” principles, in part because there are significant financial and environmental benefits to be derived from reducing, reusing and recycling construction and demolition (C&D) debris. C&D materials encompass the bulky parts of a building that industrial demolition contractors must dispose of. Plastics, metals, glass, bricks, concrete, drywall gypsum, doors, asphalt, windows and even rocks are among the most common C&D items. In past decades, demolition companies would simply discard the C&D materials from commercial, industrial and residential demolition projects. In recent years, however, many state and municipal governments have put legislation in place that requires reusing a set percentage of C&D items. Additionally, in the United States and a number of other counties around the world, LEED certification is the recognized standard for measuring building sustainability. The LEED green building rating system–developed and administered by the U.S. Green Building Council, a Washington D.C.-based, nonprofit coalition of building industry leaders–is designed to promote design and construction practices that increase profitability while reducing the negative environmental impacts of buildings and improving occupant health and well-being. LEED is an internationally recognized certification system that measures how well a building or community performs across all the metrics that matter most: energy savings, water efficiency, CO2 emissions reduction, improved indoor environmental quality, and stewardship of resources and sensitivity to their impacts. Developed by the U.S. Green Building Council (USGBC), LEED provides building owners and operators a concise framework for identifying and implementing practical and measurable green building design, construction, operations and maintenance solutions. Proper demolition practices can play a critical part in a project’s certification.
Here are a few benefits of recycling and reusing C&D materials:
1. Decreases the environmental impact of producing new building materials. It typically takes far less energy to repurpose C&D materials than it does to produce the same materials from scratch. Recycling scrap metal demolition materials, for instance, results in a 58 percent reduction in CO2 emissions over using virgin materials.
2. Generates jobs. As demolition contractors find new ways to reuse materials, new green jobs are created. For example, a 2017 report found that the scrap metal recycling industry directly supports 155,632 jobs in the United States.
3. Preserves landfill space. Here’s an outrageous fact: The U.S. produces more than 136 million tons of building-related C&D materials– equivalent to 2.8 pounds of waste every day for every man, woman and child in the country! Diverting C&D materials from these disposal streams means less waste enters our landfills.
4. Shrinks demolition expenses through decreased disposal and purchase costs. Government agencies and environmentalists aren’t the only ones who love C&D recycling–project managers are also enamored with the practice once they realize how much savings it can bring. Rather than pay hefty disposal fees, demolition supervisors often find their project costs offset by recycling scrap, concrete and other materials. Finally, the cost of erecting new buildings may be reduced by selecting repurposed C&D materials.
5. Lowers environmental cost. And perhaps most important, on a lifecycle basis, recycling produces usable materials at much less environmental cost than materials from primary sources. That is, in addition to conserving raw materials, recycling conserves energy and water and reduces the production of greenhouse emissions and other pollutants. On and off the job site, recycling is one of the most significant commitments that can be made to sustainable building. “SOURCE SEPARATION” OR “CO MMINGLED RECYCL ING” The economic benefits of recycling are highest if waste materials can be separated from each other and recycled individually. This is called “source separation.” Source separation means separating different recyclable materials at the job site. That is, workers keep metals separate from wood, and wood separate from concrete, and so on, and place each material into a different container. These containers are then transported to different markets. Commingled recycling is the alternative to source separation. Commingled recycling means placing all recyclable materials into a single container, which is then transported to a processing facility, where different materials are separated by hand or by automated equipment. The biggest tradeoff between source separation and commingled recycling is complexity vs. economics. Source separation is more complex because workers must separate waste materials before they throw them away, there are more containers on site, and there are more markets and haulers to work with and keep track of. But in most cases, source separation is economically more advantageous than commingled recycling. Source separation produces materials that are ready to go directly to market; there is no need to pay a processor to sort materials. Source-separated materials are generally of higher quality, with fewer contaminants, so they’re worth more in recycling markets.
Want to learn the latest? Best environmental and economic demolition practices will be a hot topic at the 2018 Seminar & Trade Show, March 18-21, Orlando at the Caribe Royale Resort.