Cornell study compares demolition vs. deconstruction

At the prompting of a Cornell University professor, the city of Ithaca, New York, has decided to deconstruct rather than demolish one of 11 homes in Ithaca’s Collegetown neighborhood, according to reporting by WSKG, a National Public Radio and Public Broadcasting Station based in Vestal, New York.

With the industry’s current understanding of the related economics and methods, demolition is the faster, cheaper route in many cases. However, Felix Heisel, director of the Circular Construction Lab at Cornell, Ithaca, New York, told WSKG deconstruction can be cheaper than demolition when accounting for landfill diversion, reduced carbon dioxide emissions and fewer natural resources extracted since more materials are reused in deconstruction than in demolition.

Heisel says making deconstruction cheaper is a matter of scale and repetition.

“As long as we deconstruct just one building, without the right equipment, without a workforce that is trained, then this will be more expensive than demolition,” he tells the radio station. “But with an economy of scale, that changes. It can be an economically competitive process as long as you have an economy of scale.”

The project was prompted by plans to demolish 11 homes dating from the early 20^th century to make way for 300-unit housing project, according to an outline of the project on Cornell’s Department of Architecture Art Planning’s website.

The project will inform the development of local legislation in Ithaca, which, if adopted, would make it one of just a handful of cities across the country prioritizing deconstruction over demolition, including Pittsburgh, Pennsylvania; Steamboat Springs, Colorado and Portland, Oregon, among others.

The intent of the project is to “investigate the circular potential of the local built environment by researching and proposing methods for material reuse and recycling, reversible construction, reactivating embodied values, creating green jobs and reinventing the underlying business models of construction,” Cornell says.

The Catherine Commons Deconstruction Project includes a side-by-side comparison of demolition and deconstruction on similar structures in the same economic environment. Researchers are comparing “everything from the quantity and quality of materials saved to the resale market, the time and labor required and the total cost—including environmental and social costs that are typically not factored into construction and demolition budgets,” Cornell says.

The research investigates the existing barriers to deconstruction, as well as the scalability of deconstruction for businesses. Using a process called panelized deconstruction, a crew divided the structure at 206 College Avenue into sections earlier this year, removing sections of floor, wall and roofing, removing them from the site to a warehouse where materials could be processed, Cornell says. To limit time on site, the process involves the use of heavy equipment married to more surgical removal of valuable materials from inside the structure.

Partners in the project include the Seattle-based Building Deconstruction Institute; Ithaca-based Trade Design Build; Ithaca-based Finger Lakes ReUse; the SC Johnson College of Business at Cornell and many others, including the Cornell Einhorn Center, which supported the project through the Engaged Cornell Public Purpose Grant.