Greenbuild 2007: The C&D Connection

The management of construction and demolition debris is a huge component of the green building movement, according to Wes Sullens of Alameda County, Calif.-based StopWaste.org, who moderated a session entitled Waste Not at the Greenbuild Expo held recently in Chicago.

Approximately 21 percent of the waste stream in California is C&D debris, Sullens said, and that number can reach 50 percent or more in areas with highly active building markets.

Such a large material stream translates into significant recycling opportunities and earning Leadership in Energy and Environmental Design (LEED) points for contractors looking for green building certification, he said. While recycling offers measurable upstream and downstream savings, cultivating markets for some material can be a challenge. “Finding markets for C&D is where we need to go,” said Sullens.

Richard Ludt of Interior Removal Specialist Inc., South Gate, Calif., said the diversity of the C&D debris stream is part of the problem when it comes to finding viable markets. He said C&D can be divided into two separate material streams—debris that comes from “hard demo” and “soft demo,” which includes the kind of interior demolition work his company specializes in. Debris from hard demolition includes material from full building demolition, including concrete and ferrous and nonferrous scrap metal—materials where markets are usually readily available, Ludt said. “Soft demolition” material, the kind found when working with interior spaces, includes material that is often harder to market, such as drywall, carpet and particle board, he said.

Commercial interior jobs also often have still functioning fixtures and usable furniture to deal with, Ludt said. With commercial interior jobs, Ludt said it’s even more important for contractors to focus on markets before the demolition even starts. “Look at what you can recover before you start,” he said.

Markets exist for materials like drywall and ceiling tiles, but they might be harder to find than those for scrap steel and concrete, he added. He advised contractors to source separate as much as possible.

Richard Chien from the San Francisco Department of the Environment also addressed attendees of the session and updated them on the city’s efforts to improve C&D recycling.

The city approved a C&D recycling ordinance in 2004 that took effect in the summer of 2006 to help San Francisco reach its goal of sending zero material to landfills by 2020.

Chien said the city did a waste characterization study in 2005, which showed 15 percent of the material going into landfills was C&D debris, making that material “an important part of the equation,” in reducing total waste, he said.

Also speaking on the panel was Michael Pawlyn, a consultant with U.K.-based Grimshaw Architects. Pawlyn discussed his firm’s involvement in projects that draw inspiration from nature. “Generally, we have a very linear, wasteful approach to resources,” Pawlyn said. His firm’s projects aim to reflect a more natural, closed-loop approach to the use of resources, “where waste from one part of the system becomes nutrients for another.”

The Greenbuild Expo was held Nov. 7-9 in Chicago. More information is available at www.greenbuildexpo.org.