BUILDING DECONSTRUCTION - ISSUES & METHODS

Originally Posted By 

Stephanie Nneoma Okoye

When its time for an old or defunct building to go down, many think of demolition as the first option. There is however an alternative method that has gained recognition for its green characteristics. It is called Building De-construction.

Demolition is the Traditional method of simply destroying a building or structure, reducing it down to a pile of rubble and waste which is collected and removed from the site. This is a hazardous process because it fills the nearby air with harmful dust, vapors and other compounds that are harmful to human beings. With this method, 'everything' goes to 'waste'.

Deconstruction on the other hand advocates for a more careful process of dis-assembly of buildings to recover the maximum amount of re-useable and or recycleable materials in a safe, environmentally responsible, and cost-effective manner. The materials thus recovered can be reused on the same site for a new construction, sold or donated to another site.

  

DEMOLITION VS. DE- CONSTRUCTION

	DEMOLITION	DECONSTRUCTION
Waste management	Everything goes to waste	Re-useable and re-recyclable materials are recovered
Environmental safety	It is environmentally unsafe	It is environmentally safe
Cost efficiency	It is very expensive, as all money goes into waste	It saves cost of otherwise new materials as much as possible.
Ethics	It is un-ethical and barbaric	It is a civilized way of handling old or defunct buildings.
Process	Disorderly	It is a systematic scientific process

FACTORS THAT NECESSITATE AND  ENCOURAGE DECONSTRUCTION INCLUDE:

1. Age of the building or non-functionality status.
2. Increase in the price of key materials such as metal and reinforcement bars.
3. Scarcity of some building materials
4. Increased demand for green building.
5. Increased cost of disposing demolition waste.
6. Reduction in available Landfill sites or landfill capacity.
7. Increased sensitivity of town planning and development control agencies towards ethical demolition process.
8. Increased availability of technology to make productive use of 'waste'.
9. Improved awareness of green house gas emissions due to material production.

WHO PERFORMS DECONSTRUCTION?

Deconstruction is usually done by specialized private companies. These companies acts as contractors to disassemble buildings; recovering as much as possible reusable and recyclable materials in it.

The scope of items to be recovered as well as how to re-use or re-sell them are usually agreed upfront with the building owner.

THE DECONSTRUCTION PROCESS

The process of deconstructing a building can be broken down into three main phases:

A. SKIMMING : This refers to the pre-demolition stage where the building owner collects removeable belongings that are handy and light such as office equipments, picture frames, files .t.c

B. SOFT-STRIPPING: This refers to the removal of non-structural elements such as doors, windows, wallpapers, electrical fixtures, mechanical fixtures, e.t.c

C. STRUCTURAL DECONSTRUCTION: This refers to the careful demolition of the structural members of the whole building such as columns, beams e.t.c

TECHNICAL CONSIDERATIONS

Several factors are considered when investigating the possibility of carrying out building deconstruction practice. These include:

1. The condition of the building and materials.
2. Types and quantity of the reusable and recyclable materials.
3. The closest market for resell or re use of the potential recovery.
4. Safety of live and properties during the process. Usually the process begins with the 'last on, first off' principle, where the building is deconstructed in reverse order of how they were constructed. They must be well assessed to identify and handle materials that pose potential hazards such as asbestos, lead based paints, mercury lamps, e.t.c
5. Cost of transporting recovered items as well as waste materials.

BENEFITS OF DECONSTRUCTION

The benefits can largely be divided into three namely:

A. ECONOMIC BENEFITS:

When deconstruction is done to reduce the amount of waste that is dumped at landfill sites, disposal costs are reduced.

Reuse of recovered materials saves cost purchasing new ones.

Donation to other sites or independent salvage bodies, helps reduce their cost of purchasing new ones.

Start-up owners who require cheaper materials for low-cost housing, can take advantage of these recycled materials.

B. ENVIRONMENTAL BENEFITS:

It is generally 'greener' than traditional demolition process.

C. SOCIOLOGICAL BENEFITS:

Deconstruction is a means of employment as it requires skilled and unskilled labor at several stages. It is not so in demolition which typically anyone can do.

In conclusion, the government, building owners, ministries and parastatals responsible for development control as well as Architects and Engineers all have a role to play in adopting deconstruction methods which as we have seen is more beneficial to the environment, the economy and to our health.

 References:

G.Bradley Guy, Building Deconstruction case study; "Reuse and recycling of building materials", Powell Center for Construction and Environment, University of Florida.

Mary Zimmerman, HfH, Personal Communication,

Hammer center for Community Design, 2006.

Do you think Deconstruction is well practisced in Nigeria? Have you performed it before? Use the form below to share your ideas.