Designed for Efficiency and Destruction
July 24, 2007
The design, construction, renovation and demolition of buildings accounts for literally tons of wasted materials, not to mention energy. Some ways to minimize building waste start from designing for destruction.
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, according to the U.S. Environmental Protection Agency (EPA).
C&D debris consists of the materials generated during the construction, renovation and demolition of buildings, roads, and bridges. According to the EPA, C&D debris often contains bulky, heavy materials that include the following: concrete; wood (structural lumber and tree branches/stumps); asphalt from paved surfaces and roofing shingles; gypsum from drywall; metals from plumbing fixtures; bricks; glass; plastics; earth and rock from clearing sites and altering the topography; and cardboard from containers.
Only 9 percent of the C&D debris generated each year comes from new construction, according to Annette Puskarich is recycling coordinator for the City of Palo Alto Public Works Department, at Western City magazine. The other 91 percent comes from from renovation and demolition.
Reduce and Recycle Waste Reducing and recycling C&D debris not only conserves landfill space and reduces the environmental impact of producing new materials it also creates jobs and can reduce overall building project expenses through avoided purchase/disposal costs, according to the EPA.
In design and construction, one way to minimize the high percentage of C&D debris is in creating adjustable structuring, which can save both time and money by minimizing future demolition. Creating building components that are disassembled easily also enables a building to be updated in a way that minimizes construction waste. For example, removable and mobile parts allow for modernizing a building's electrical system and can lower economic and environmental costs.
With so much construction waste on our hands, it may be difficult to determine just where to begin. HGTVPro.com notes that almost 40 percent of job-site waste is wood:
An estimated one-sixth of the wood delivered to the job site ends up in the landfill. Spare ends from framing and leftover pieces from roof, floor and siding sheathing go into the dumpster when they might actually be reused or recycled.
As with paper in the office, HGTVPro notes that the oft-overlooked key to conserving forest products is to reduce the amount used in the first place. "Optimum value engineering (OVE) is a design technique that reduces the overall amount of lumber needed for construction while actually improving the energy efficiency and reducing labor costs," writes Andrew Hunt. "One common part of OVE is to move the standard 16-inch center wall framing to 24-inch centers."
The labor requirement and material costs decline while allowing for more continuous insulation. With the cost of transporting all kinds of products rising due to higher fuel prices, there's further pressure to minimize material costs.
In the demolition stage, deconstruction enables building materials to be salvaged and recovered for reuse, which is a better use than recycling. Deconstruction is the process of taking apart a building in the reverse order it was constructed to reduce the overall cost of building removals, provide lower-cost building materials to the community and extend the life of landfills. (For more on this, see Deconstruction: A Practice Worth Salvaging.)
Integrated Design Another alternative building strategy for waste reduction is integrated design. The amount of energy conserved depends on what happens in the planning stage. A focus on integrated building design for energy efficiency enables architects and builders to create houses and commercial/industrial facilities that will require less energy to operate.
According to the Department of Energy (DOE):
Integrated building design is a process of design in which multiple disciplines and seemingly unrelated aspects of design are integrated in a manner that permits synergistic benefits to be realized. The goal is to achieve high performance and multiple benefits at a lower cost than the total for all the components combined.
In an integrated design approach, major design issues should be considered by all members of the design team from civil engineers to interior designers who have common goals that were set in the building program, including those in the fields of general architecture, HVAC, lighting and electrical, interior design and landscape design.
For example, the mechanical engineer would calculate energy use and cost very early in the design, informing designers of the energy-use implications of building orientation, configuration, fenestration, mechanical systems and lighting options.
The DOE goes on to suggest:
The procurement of architectural and engineering (A&E) services should stress a team-building approach, and provisions for integrated design should be clearly presented in the statement of work (SOW). For example, the SOW should stipulate frequent meetings and a significant level of effort from mechanical engineers to evaluate design options.
The design and analysis process for developing integrated building designs includes the following:
Establishing a base case; Identifying a range of solutions; Evaluating the performance of individual strategies; Grouping strategies that are high performers into different combinations to evaluate performance. Selecting strategies, refining the design and reiterating the analysis throughout the process.
In addition to costing less to operate, Energy Design Resources says, using integrated design can make a building easier to maintain and more attractive, marketable and comfortable.
For more information and additional resources on how to minimize waste in building materials and design, visit "Integrated Building Design for Energy Efficiency" in the DOE's Building Toolbox, "Construction and demolition (C&D) debris" at the EPA, and "Design Practices: Integrated Energy Design" at EnergyDesignResources.com.
Lifecycle Building Challenge, Designing this Building and the Next Closing the Circle News, Winter-Spring, 2007
Deconstruction: A Practice Worth Salvaging by Annette Puskarich Western City Magazine, July 2007
Integrated Building Design for Energy Efficiency U.S. Department of Energy