Heatwaves, power outages, extreme cold and drought -- you need to look no further than the day’s headlines to realize our climate is changing and there is an urgent need to do better for the environment. The construction industry has a huge role to play.
The Environmental Protection Agency (EPA) has studied and quantified the scope of the construction waste problem. In its most recent report, it found 600 million tons of construction and demolition (C&D) debris were generated in the United States in 2018. That’s more than twice the volume of municipal waste generated by homes and businesses.
Not surprisingly, the vast majority of that waste comes from demolition. Just over 455 million tons of C&D debris -- mostly aggregate -- were directed to next use. That’s the good news. But around 145 million tons were sent to landfills.
Nonetheless, the construction industry is making moves in the right direction, effectively reducing waste, reusing materials, and getting good recycling practices in place.
The expansion of modular methods of construction creates efficiency and minimizes waste.
Prefabrication offsite means parts are built in an assembly-line fashion, to exact specifications, with virtually no waste. The predictability and replicability of building parts in a manufacturing-type facility make it possible for installation to set the cadence and improve schedule certainty. Specialized tools, parts, and processes support efficiency. Quality assurance and controls are stringently applied in the manufacturing setting which are precursors to continuous improvement, so quality is on an ever-upward trajectory and waste is virtually eliminated.
Prefabrication pairs well with an industrialized approach to scheduling. This carefully sequenced, manufacturing style approach to assembly means fewer crews working fewer shifts, driving trucks, and operating heavy machinery. A carefully crafted and proven delivery sequence allows for precise planning and organized subcomponents to be installed on a schedule with minimal construction waste. It makes projects run efficiently and enhances safety.
So many building materials can be recycled now. At Compass, for instance, we approach new builds and material selection with future repurposing in mind, favoring those materials with the potential to balance the site’s environmental impact.
Asphalt, concrete, and rubble are often recycled into aggregate or new asphalt and concrete products. Wood can be recycled into engineered-wood products like furniture, as well as mulch, compost, and other products. Metals—including steel, copper, and brass—are also valuable commodities to recycle.
There are a couple of different approaches to recycling to fit the project, crew, and budget. Site separated so the builder sorts waste by product. It takes more time but makes sense if you’re working with a host of recyclable materials that can be easily sorted. Commingled recycling means everything goes in one container and the hauler does the sorting. This makes it easier on field staff and saves time.
Compass comingles recycled materials and strives for no more than 10% of construction material waste. This applies to both green and brownfield sites, and also process fill materials onsite, using demo debris and rock from over-excavation.
Retrofits, or adaptive reuse, are gaining popularity. For some, the driver is purely aesthetic. Developers are putting interesting buildings back in service. From a sustainable perspective, adaptive reuse minimizes the manufacturing of new materials. In addition to saving on the cost of materials, local governments often incentivize re-use and repurposing of old buildings, and adaptive reuse can qualify for grants and other special funds so there are strong incentives for businesses that can make use of old buildings. Finally, old buildings are often constructed with higher-quality materials (e.g., stone and masonry that is highly climate responsive). New buildings can cost much more to achieve similar efficiency.
The data center industry has supported reuse of buildings, adapting otherwise unusable, expansive, abandoned land and structures like malls, prisons, and power plants. Data centers are in high demand and have increasingly large footprints in an era where land in reasonable proximity to business districts – necessary to meet evolving latency restrictions -- isn’t easy to come by. There are some very practical benefits to adapting existing structures, and an important opportunity to keep huge volumes of building materials out of landfills.
As we move forward with sustainability top of mind, architects and engineers should design buildings with adaptation in mind. Planning for disassembly and reuse to reduce waste and keep the building and the component parts in service minimizes energy consumption and waste down the line. This practice allows materials to be easily and cost-effectively taken apart and directed to a future application and goes a long way toward minimizing waste.
The shift toward a circular economy -- promoting the elimination of waste and the continual, safe use of resources -- is critical to forging a more sustainable future. Adapting old structures for current needs, leaning into efficiency gains from modular components and streamlined schedules, and recycling are important steps in the right direction that our industry can continue to embrace and expand. Being mindful of circularity and building for the long-term is our big opportunity to be forward looking and lead as an industry toward a more sustainable future.
Did you know?
The EPA offers the following strategies for designing for adaptability, disassembly and reuse, including: