Deconstruction (building) - AbsoluteAstronomy.com

In the context of physical construction

Construction

In the fields of architecture and civil engineering, construction is a process that consists of the building or assembling of infrastructure. Far from being a single activity, large scale construction is a feat of human multitasking...

, deconstruction is the selective dismantlement of building components, specifically for re-use, recycling

Recycling

Recycling is processing used materials into new products to prevent waste of potentially useful materials, reduce the consumption of fresh raw materials, reduce energy usage, reduce air pollution and water pollution by reducing the need for "conventional" waste disposal, and lower greenhouse...

, and waste management

Waste management

Waste management is the collection, transport, processing or disposal,managing and monitoring of waste materials. The term usually relates to materials produced by human activity, and the process is generally undertaken to reduce their effect on health, the environment or aesthetics...

. It differs from demolition

Demolition

Demolition is the tearing-down of buildings and other structures, the opposite of construction. Demolition contrasts with deconstruction, which involves taking a building apart while carefully preserving valuable elements for re-use....

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

Green building

Green building refers to a structure and using process that is environmentally responsible and resource-efficient throughout a building's life-cycle: from siting to design, construction, operation, maintenance, renovation, and demolition...

. 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 landfill

Landfill

A landfill site , is a site for the disposal of waste materials by burial and is the oldest form of waste treatment...

s. Building implosion

Building implosion

In the controlled demolition industry, building implosion is the strategic placing of explosive material and timing of its detonation so that a structure collapses on itself in a matter of seconds, minimizing the physical damage to its immediate surroundings...

s or ‘wrecking-ball’ style demolition

Demolition

s 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

Waste

Waste is unwanted or useless materials. In biology, waste is any of the many unwanted substances or toxins that are expelled from living organisms, metabolic waste; such as urea, sweat or feces. Litter is waste which has been disposed of improperly...

” and reclaiming it into useful building material.

Contribution to sustainability

Deconstruction has strong ties to environmental sustainability

Sustainability

Sustainability is the capacity to endure. For humans, sustainability is the long-term maintenance of well being, which has environmental, economic, and social dimensions, and encompasses the concept of union, an interdependent relationship and mutual responsible position with all living and non...

. 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

Energy

In physics, energy is an indirectly observed quantity. It is often understood as the ability a physical system has to do work on other physical systems...

and emissions

Air pollution

Air pollution is the introduction of chemicals, particulate matter, or biological materials that cause harm or discomfort to humans or other living organisms, or cause damage to the natural environment or built environment, into the atmosphere....

reductions from the refining

Refining

Refining is the process of purification of a substance or a form. The term is usually used of a natural resource that is almost in a usable form, but which is more useful in its pure form. For instance, most types of natural petroleum will burn straight from the ground, but it will burn poorly...

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.

Benefits of avoiding wood waste

In Canada, the CO2 Neutral Alliance has created a website with resources for regulators and municipalities, developers and contractors, business owners and operators, and individuals and households. Benefits for municipalities include:

Reducing disposal costs where waste collection, hauling or disposal is supported by the tax base
Establishing additional revenue streams
Making existing landfills last longer
Reducing greenhouse gas emissions caused by the decomposition of wood waste into methane from landfills
Stimulating local economies with new industries and employment

Improving the local environment and overall sustainability of your community
For every three square feet of deconstruction, enough lumber can be salvaged to build one square foot of new construction. At this rate, if deconstruction replaced residential demolition, the United States could generate enough recovered wood to construct 120,000 new affordable homes each year. The deconstruction of a typical 2000 square feet (185.8 m²) wood frame home can yield 6,000 board feet of reusable lumber.
Every year the United States buries about 33 million tons of wood-related construction and demolition debris in landfills. As anaerobic microorganisms decompose this wood, it will release about five million tons of carbon equivalent in the form of methane gas.

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, door

Door

A door is a movable structure used to open and close off an entrance, typically consisting of a panel that swings on hinges or that slides or rotates inside of a space....

s, window

Window

A window is a transparent or translucent opening in a wall or door that allows the passage of light and, if not closed or sealed, air and sound. Windows are usually glazed or covered in some other transparent or translucent material like float glass. Windows are held in place by frames, which...

s, 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

Brick

A brick is a block of ceramic material used in masonry construction, usually laid using various kinds of mortar. It has been regarded as one of the longest lasting and strongest building materials used throughout history.-History:...

, dimension stone

Dimension stone

Dimension stone is natural stone or rock that has been selected and fabricated to specific sizes or shapes. Color, texture and pattern, and surface finish of the stone are also normal requirements...

, and extinct wood

Wood

Wood is a hard, fibrous tissue found in many trees. It has been used for hundreds of thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers embedded in a matrix of lignin which resists compression...

. 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

Lumber

Lumber or timber is wood in any of its stages from felling through readiness for use as structural material for construction, or wood pulp for paper production....

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

Barracks

Barracks are specialised buildings for permanent military accommodation; the word may apply to separate housing blocks or to complete complexes. Their main object is to separate soldiers from the civilian population and reinforce discipline, training and esprit de corps. They were sometimes called...

, 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

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

, 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

Region

Region is most commonly found as a term used in terrestrial and astrophysics sciences also an area, notably among the different sub-disciplines of geography, studied by regional geographers. Regions consist of subregions that contain clusters of like areas that are distinctive by their uniformity...

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

Income tax

An income tax is a tax levied on the income of individuals or businesses . Various income tax systems exist, with varying degrees of tax incidence. Income taxation can be progressive, proportional, or regressive. When the tax is levied on the income of companies, it is often called a corporate...

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 organization

Non-profit organization

Nonprofit organization is neither a legal nor technical definition but generally refers to an organization that uses surplus revenues to achieve its goals, rather than distributing them as profit or dividends...

s 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

United States Green Building Council

The U.S. Green Building Council , co-founded by Mike Italiano, David Gottfried and Rick Fedrizzi in 1993, is a non-profit trade organization that promotes sustainability in how buildings are designed, built, and operated...

's program entitled Leadership in Energy and Environmental Design

Leadership in Energy and Environmental Design

Leadership in Energy and Environmental Design consists of a suite of rating systems for the design, construction and operation of high performance green buildings, homes and neighborhoods....

(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

Dimension stone

Dimension stone is natural stone or rock that has been selected and fabricated to specific sizes or shapes. Color, texture and pattern, and surface finish of the stone are also normal requirements...

.

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.

Process

When choosing to deconstruct a building there are some important aspects that need to be taken into consideration. Developing a list of local contacts that are able to take used materials is an essential first step. These might include commercial architectural salvage businesses, reclamation yards, not-for-profit and social enterprise salvage warehouses, and dismantling contractors. Materials that cannot be salvaged may be recycled on-site or off-site, or taken to landfills. The next step involves identifying which, if any, are hazardous materials. Lead paint

Lead paint

Lead paint or lead-based paint is paint containing lead, a heavy metal, that is used as pigment, with lead chromate and lead carbonate being the most common. Lead is also added to paint to speed drying, increase durability, retain a fresh appearance, and resist moisture that causes corrosion...

and asbestos

Asbestos

Asbestos is a set of six naturally occurring silicate minerals used commercially for their desirable physical properties. They all have in common their eponymous, asbestiform habit: long, thin fibrous crystals...

are two substances in particular that need to be handled extremely cautiously and disposed of properly.

It is common practice, and common sense, to “soft-strip” the structure first; remove all appliances, windows, doors, and other finishing materials. These will account for a large percentage of the marketable components. After the non-structural deconstruction, structural is the next step. It is best to start at the roof

Roof

A roof is the covering on the uppermost part of a building. A roof protects the building and its contents from the effects of weather. Structures that require roofs range from a letter box to a cathedral or stadium, dwellings being the most numerous....

and work down to the foundation

Foundation (architecture)

A foundation is the lowest and supporting layer of a structure. Foundations are generally divided into two categories: shallow foundations and deep foundations.-Shallow foundations:...

.

Building components that are dismantled will need to be stored in a secure, dry location. This will protect them from water damage

Water damage

Water damage describes a large number of possible losses caused by water intruding where it will enable attack of a material or system by destructive processes such as rotting of wood, growth, rusting of steel, de-laminating of materials such as plywood , and many, many others.The damage may be...

and theft. Once separated from the structure, materials can also be cleaned and/or refinished to increase value. Building an inventory list of the materials at hand will help determine where each item will be sent.

Designing for deconstruction (DfD)

"The end of the building’s useful life generates a stream of used materials that can be reprocessed for new construction. The selection of materials for reuse or recycling should not start at the end of the building’s life cycle, it should start at the design stage. Architects and engineers should keep the whole life cycle of the building in mind and select construction materials based on their capacity to be reused or recycled after the building has served its purpose."

An upstream approach to deconstruction can be implemented into buildings during their design process. This is a current trend in sustainable architecture

Architecture

Architecture is both the process and product of planning, designing and construction. Architectural works, in the material form of buildings, are often perceived as cultural and political symbols and as works of art...

. Often, simple construction methods combined with high-grade, durable materials work best for DfD structures. Separating layers of a building’s infrastructure and making them visible can significantly simplify its deconstruction. Making components within systems separable also assists in being able to dismantle materials quickly and efficiently. This can be achieved by using mechanical fasteners such as bolts to connect parts. Allowing physical access to the fasteners is another needed aspect of this design. Also, it is important to use standardized materials and assemble them in a consistent manner throughout the project.

Some conventional construction methods and materials are difficult or impossible to deconstruct and should be avoided when designing for deconstruction. The use of nails and adhesives significantly slows down the deconstruction process and has a tendency to ruin otherwise reusable materials. Avoid hazardous materials altogether as they are detrimental to the natural environment and are non-reusable. Using mixed material grades makes the process of identifying pieces for resale difficult.

Deconstruction is important for more than just the end of a building’s life-cycle. Buildings that have been designed with deconstruction in mind are often easier to maintain and adapt to new uses. Saving the shell of a building or adapting interior spaces to meet new needs ensures that new structures have a small environmental impact.

An alternative worth considering is modular building

Modular building

Modular buildings and modular homes are sectional prefabricated buildings or houses that consist of multiple modules or sections which are built in a remote facility and then delivered to their intended site of use...

, like the Habitat 67 project in Montreal, Canada. This was a residential structure consisting of separate, functional apartments that could be put together in a variety of ways. As people moved in or out, the units could be reconfigured as desired.

External links

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