Circular construction could be a huge boon for climate—and jobs

A circular construction industry could prevent substantial greenhouse gas emissions and unlock up to $3 billion of economic growth for New York State, researchers from Cornell University write in a new white paper.

Construction, renovation, and demolition of buildings in New York generates 7.7 million tons of waste every year, and 58% of this material winds up buried in a landfill, burned, or shipped off to another country for disposal.

This linear construction industry also has a hefty climate footprint. Buildings and waste are the first and fourth largest sources of human-caused greenhouse gas emissions in the state, together responsible for 43% of emissions.

The social costs are high too: indiscriminate demolition releases toxic dust that poisons nearby air and waterways. Disposal of the resulting waste worsens the strain on the state’s overtaxed landfills, which taxpayers must pay to maintain for decades after their closure.

In contrast, “Circular construction aims to design and construct buildings as material banks for future construction, extend the life of today’s built environment, and activate the potential of existing structures at the end of their service lives as ‘anthropogenic mines’ of useful materials,” the researchers write.

While 42% of construction and demolition debris is currently recycled, this mostly amounts to downcycling, turning an undifferentiated mass of mixed materials into low-value products like aggregate and landfill cover. Just 0.4% of building debris is currently reused in new construction.

Deconstruction—taking buildings apart piece by piece rather than indiscriminately bulldozing them—could enable at least 90% of building materials to be reused or recycled, the researchers say.

Deconstruction can reclaim valuable building materials ranging from lumber and steel to windows and trim, and even kitchen cabinetry and bathroom fixtures. This painstaking work is more labor-intensive than demolition, so it creates more jobs—including entry-level positions that could help people get started in skilled building trades.

In the new study, the researchers calculated that if 75% of residential demolitions in New York were shifted to deconstruction instead, this would create 12,600 new green jobs. This scenario would unlock a total of $3.05 billion dollars of economic benefits for the state.

While deconstruction is more expensive than demolition for property owners, they can often recoup the costs by selling reclaimed materials. “Further, reclaimed building materials are often more affordable than virgin materials, providing increased access for low- income households,” the researchers write.

What’s more, deconstruction is a local solution: the dollars tend to circulate within the community, and the construction industry becomes less vulnerable to disruptions of convoluted international supply chains such as those that occurred at the peak of the COVID-19 pandemic.

“While reuse is the preferred outcome, the more careful nature of deconstruction also produces improved recycling yields for materials that cannot be reused,” the researchers add. This is because different types of building materials are sorted at the source, “which, in turn, provides more homogeneous feedstocks for recyclers.”

Finally, there are substantial climate benefits from reducing embodied carbon emissions—meaning those that are contained in the structure and materials that go into a building, rather than those arising from its use. “Reuse of existing buildings and/or materials will reduce [embodied] emissions, often by as much as 75% compared with demolishing and building new, as reuse cuts out the most emitting stages of extraction and manufacturing,” the researchers write.

Some municipal and state-level initiatives in New York and nationwide have encouraged building deconstruction and reuse, but more efforts are needed, the researchers say. They detail nearly two dozen policies that could advance deconstruction, including establishing a certification and training program for contractors, revising building codes to permit and even encourage reused materials, and enacting a surcharge on disposal of construction materials.

Source: Heisel F. et al. (eds.) “Constructing a Circular Economy in New York State: Deconstruction and Building Material Reuse.” Ithaca, NY: Cornell Circular Construction Lab, Cornell Just Places Lab, and CR0WD, 2024.

Image: © Anthropocene Magazine