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Deconstruction is the selective dismantlement of building components, specifically for re-use, recycling, and waste management. It differs from demolition where a site is cleared of its building by the most expedient means. Deconstruction has also been defined as “construction in reverse”. The process of dismantling structures is an ancient activity that has been revived by the growing field of sustainable, green building. Buildings, like everything, have a life-cycle. Deconstruction focuses on giving the materials within a building a new life once the building as a whole can no longer continue.
When buildings reach the end of their useful life, they are typically demolished and hauled to landfills. Building implosions or ‘wrecking-ball’ style demolitions are relatively inexpensive and offer a quick method of clearing sites for new structures. On the other hand, these methods create substantial amounts of waste. Components within old buildings may still be valuable, sometimes more valuable than at the time the building was constructed. Deconstruction is a method of harvesting what is commonly considered “waste” and reclaiming it into useful building material.
Contribution To Sustainability
Deconstruction has strong ties to environmental sustainability. In addition to giving materials a new life cycle, deconstructing buildings helps to lower the need for virgin resources. This in turn leads to energy and emissions reductions from the refining and manufacture of new materials. As deconstruction is often done on a local level, many times on-site, energy and emissions are also saved in the transportation of materials. Deconstruction can potentially support communities by providing local jobs and renovated structures. Deconstruction work typically employs 3-6 workers for every one employed in a comparable demolition job. In addition, solid waste from conventional demolition is diverted from landfills. This is a major benefit because construction and demolition (C&D) waste accounts for approximately 20% of the solid waste stream.
Typical Methods of Deconstruction
Deconstruction is commonly separated into two categories; structural and non-structural. Non-structural deconstruction, also known as “soft-stripping”, consists of reclaiming non-structural components, appliances, doors, windows, and finish materials. The reuse of these types of materials is commonplace and considered to be a mature market in many locales.
Structural deconstruction involves dismantling the structural components of a building. Traditionally this had only been performed to reclaim expensive or rare materials such as used brick, dimension stone, and extinct wood. In antiquity, it was common to raze stone buildings and reuse the stone; it was also common to steal stones from a building that was not being totally demolished: this is the literal meaning of the word dilapidated. Used brick and dimension limestone in particular have a long tradition of reuse due to their durability and color changes over time. Recently, the rise of environmental awareness and sustainable building has made a much wider range of materials worthy of structural deconstruction. Low-end, commonplace materials such as dimensional lumber have become part of this newly emerging market.
The United States military has utilized structural deconstruction in many of its bases. The construction methods of barracks, among other base structures, are usually relatively simple. They typically contained large amounts of lumber and used minimal adhesives and finish-work. In addition, the buildings are often identical, making the process of deconstructing multiple buildings much easier. Many barracks were built during the era prior to WWII, and have aged to the point where they now need to be torn down. Deconstruction was deemed very practical due to the abundance of labor the military has access to and the value of the materials themselves.
Natural disasters, such as hurricanes, floods, tsunamis, and earthquakes often leave a vast amount of usable building materials in their wake. Structures that remain standing are often deconstructed to provide materials for rebuilding the region.
Economic potential
Deconstruction’s economic viability varies from project to project. The amount of time and cost of labor are the main drawbacks. Harvesting materials from a structure can take weeks, whereas demolition may be completed in roughly a day. However, some of the costs, if not all, can be recovered. Reusing the materials in a new on-site structure, selling reclaimed materials, donating materials for income tax write-offs, and avoiding landfill “tipping fees” are all ways in which the cost of deconstruction can be made comparable to demolition.
Reclaiming the materials for a new on-site structure is the most economically and environmentally efficient option. Tipping fees and the costs of new materials are avoided; in addition, the transportation of the materials is non-existent. Selling the used materials or donating them to non-profit organizations are another effective way of gaining capital. Donations to NPO’s such as Habitat for Humanity’s ReStore are tax deductible. Many times it is possible to claim the value to be half of what that particular material would cost new. When donating rare or antique components it is sometimes possible to claim a higher value than a comparable, brand-new material.
Value can also be added to new structures that are built by implementing reused materials. The United States Green Building Council's program entitled Leadership in Energy and Environmental Design (LEED) offers seven credits relating to reusing materials. (This accounts for seven out of a maximum sixty-nine credits) These include credits for building-shell reuse, material reuse, and diverting waste from landfills. Building shell-reuse is particularly appropriate for shells made of dimension stone.
Deconstruction is well suited to job training for the construction trades. Taking down a building is an excellent way for a worker to learn how to put a building up. This is vital for the economic recovery of inner-city communities. Unskilled and low-skilled workers can receive on-the-job training in use of basic carpentry tools and techniques, as well as learning teamwork, problem-solving, critical thinking and good work habits.
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