Climate Change: Deconstruction - A Practice Worth Salvaging
Annette Puskarich is recycling coordinator for the City of Palo Alto Public Works Department and can be reached at firstname.lastname@example.org.
As a nation, we’re generating a lot of waste. According to the U.S. Environmental Protection Agency (EPA), materials discarded from building-related activities, known as construction and demolition (C&D) debris, account for one-third of the total waste generated in the United States.
Only 9 percent of the C&D debris generated each year comes from new construction. The other 91 percent -- from renovation and demolition -- is usually either recycled or sent to landfills. As communities strive to be more "green" by diverting materials from landfills and reducing greenhouse gases, building deconstruction provides an alternative to traditional demolition and subsequent debris recycling.
What Is Deconstruction?
Deconstruction is the process of removing a building by taking it apart in the reverse order it was constructed. Deconstruction enables building materials to be salvaged and recovered for reuse, which is a better use than recycling.
Deconstructing buildings for reuse can:
- Reduce the overall cost of building removals (including tax incentives in some cases);
- Provide lower-cost building materials to the community;
- Extend the life of landfills;
- Protect the natural environment by reducing the need to extract new resources;
- Support the viability of the reuse business sector; and
- Create job training potential and jobs in the building trades.
When considering deconstruction, there is much more at stake than the building whose useful life has come to an end. The "embodied" or total energy expended in the original creation of that building -- from building material development to actual construction -- is significant. Energy is consumed at each stage of a building’s creation: during the extraction of raw materials; manufacturing raw materials into building materials; transporting materials through the distribution chain and to the project site; and by the equipment and tools used to assemble the materials into the actual building. Deconstruction prevents the loss of that embodied energy and emission of the greenhouse gases created by producing replacement building materials.
The City of Palo Alto requires salvage as part of its C&D debris reuse and recycling ordinance. Robust demolition and remodeling activities are under way in the community, and the city is working to improve the reuse component of its program. City staff sees great opportunities for used building materials to be captured and recognizes the significant social, economic and environmental benefits of these efforts.
For example, according to the Deconstruction Institute (a project whose mission is to inspire and support deconstruction and materials reuse), a 2,000-square-foot home contains 892 million British thermal units (BTUs) of embodied energy, an amount of energy equal to 7,826 gallons of gasoline or enough to drive an SUV five and a half times around the earth (not recommended). Reusing building materials results in the maximum possible preservation of embodied energy. With only a minimal expenditure of energy to clean and transport the reused materials to a new building site, their lifespan -- and the original investment of energy to create them -- is extended. The 6,000 board feet of lumber that can be salvaged and reused from an average single family home contains 23 million BTUs of embodied energy that can be preserved through deconstruction (equivalent to 205 gallons of gasoline).
Lumber can be reused for nonstructural elements; in some cases it can be used structurally if properly graded and approved by the local building inspector. Steel and wood beams, windows, doors, stair treads, tubs, toilets, sinks, brick, pavers, plumbing and lighting fixtures, and architectural details are all candidates for reuse. Redwood siding can be resurfaced and used for an addition to a home. Other reuses include transforming tightly grained redwood or Douglas fir into attractive furniture, or turning old bowling alley lanes and gymnasium floors into tables, countertops and flooring.
Deconstructed materials make their way to the next use in a variety of ways. Materials may be sold directly from the house by deconstruction companies that hold salvage sales (similar to a garage sale but buyers remove the building materials right from the structure), taken to a local or regional warehouse for resale, or even transported out of the state or country. Using newspaper classified ads or free online listings like Craigslist and Freecycle, and even the low-tech approach of putting unwanted building materials at the curb with a "free" sign, are a few ways to market and advertise the availability of deconstructed materials.
Both residential and commercial buildings can make use of deconstruction, and case studies document the advantages of deconstruction projects and offer cost analyses of demolition versus deconstruction. In the past five years, deconstruction has increased slightly due to its inclusion as an element in commercial and residential green building project checklists such as LEED and GreenPoints (see page 43 for more about LEED). But if one examines a local jurisdiction’s solid waste recycling and disposal tonnages, the numbers reflect very little deconstruction and salvage for reuse.
What Your City Can Do
Deconstruction and building materials reuse are opportunities and resources not to be wasted. Local government plays an important role. Here are some ways your city can support deconstruction:
- Educate residents and building professionals about the value of deconstruction; share deconstruction case studies and provide resources indicating where deconstruction contractors and used building material warehouses are located.
- Craft C&D debris diversion ordinances that require salvage efforts. Require project applicants to justify why deconstruction is not possible if it is not part of their plan.
- Lead by example and require that public buildings incorporate deconstruction.
- Provide a location for a used building materials drop-off or exchange, or work to bring this type of business to your community.
- Work with local trade associations and building exchanges to grow the pool of experienced deconstruction crews.