CHAPTER 2

LITERATURE REVIEW

2.1 GENERAL

The basic principle of prefabrication, whereby a home is prefabricated in one

location and then delivered to another, has been around for at least a few hundred years. The

most widely cited benefit of prefab is economy of scale, as components or entire homes can be

produced in large quantities. But this is not a prerequisite for success. There’s value in faster

project schedules, fewer weather delays, and more efficient use of materials thanks to

optimization and quality control. One of the primary benefits for the buyer is predictability:

Predefined design details and construction processes give the client a degree of surety about the

outcome that is often absent in custom projects.

2.2 PRESENT SCENARIO AROUND THE GLOBE

Between 1908 and 1940, Sears, Roebuck, and Company sold over 70,000

prefabricated house kits by mail to enterprising do-it-yourselfers across North America. These

ready-to-assemble homes featured precut wooden components cross-referenced to a blueprint.

Thanks to robust engineering, durable materials, and some good craftsmanship, many of these

homes are still in use.

After World War II the United States faced a severe housing shortage, and several

ventures attempted to use industrialized factory-built housing to solve the crisis, including

Lustron Homes and the General Panel Corporation. The Eames House, in Pacific Palisades,

California (1949), explored the idea that a home could be constructed from off-the-shelf

industrial parts and harness economies of scale for ready-made components.

In the 1970s the U.S. Department of Housing and Urban Development (HUD)

sponsored Operation Break-through, which advocated the use of factory-based industrialization

and mass production in the national home-building industry as a way to drive down costs and

make housing more affordable. Unfortunately, Operation Breakthrough did not break through,

and the entrenched method of site-building homes remained in place.

Throughout the 20th century, the promise of prefab captivated architects and

designers. Luminaries like Frank Lloyd Wright, Walter Gropius, and Buckminster Fuller were

among many who experimented with prototypes intended for mass production–a goal none of

them achieved.

The last decade has seen a resurgence of interest in prefab as entrepreneurial

architects redefine the architect-client relationship around a product-based business rather than a

service-based practice. Most of today’s models are manufactured in small quantities to the same

codes and with similar materials to site-built houses.

The most widely cited benefit of prefab is economy of scale, as components or entire

homes can be produced in large quantities. But this is not a prerequisite for success. There’s

value in faster project schedules, fewer weather delays, and more efficient use of materials

thanks to optimization and quality control. One of the primary benefits for the buyer is

predictability: Predefined design details and construction processes give the client a degree of

surety about the outcome that is often absent in custom projects.

Few of the following development trends have been adopted in the recent projects:

• Majority of the latent defects such as poor joining and water leakage problems found in

previous projects have been eliminated using in-situ fixed approach.

• Application has been diversified to other form of building construction.

• Capable to apply to the construction of rather complicate-shaped buildings.

• More precast elements are involved in the construction process.

• Other techniques like the using of mechanical formwork system, lost-form or tensioning

techniques, are incorporated in the construction process (Ref. 2)

2.3 PREFABRICATION IN DEVELOPING COUNTRIES: A CASE STUDY OF INDIA

Prefabrication in India began with the emergence of the Hindustan Housing

Factory. The company was developed by the first Prime Minister of India, Pandit Jawaharlal

Nehru, as a solution to the housing crisis that resulted from the influx of refugees from West

Pakistan in the 1950s. The Hindustan Housing Factory pioneered the production of pre-stressed

concrete railway sleepers to replace dilapidated wooden sleepers on Indian Railways. The

company changed its name shortly thereafter to reflect the diversity of its operations. It is now

known as the Hindustan Prefab Limited or HPL. Located in Delhi, today the government- run

company prefabricates primarily precast concrete for architectural and civil projects throughout

greater India.

When HPL began it was intended to produce low-income housing solutions for

the deficit in India. Precast wall panels and frame members such as beams and columns provided

a much needed set of tools to erect quick structures for mass housing. The most difficult

technology transfer obstacle for the HPL has been the cost of machinery and materials for

production. Since the government could not recoup the return on investment for the factory

through housing production, prefabrication from HPL began to service other markets including

higher dollar civil and larger public and hotel buildings.

The quality of construction is much higher when components are manufactured in a

stable environment such as the factory. This is especially true in India where today,

prefabrication has become synonymous with durable, modern, and western construction

methods. Materials are used more efficiently, are safer from climatic damage, and can be reused

in the material stream. Because of these benefits, a general consensus in India is to move

prefabricated building systems beyond precast concrete for large-scale construction to additional

market sectors including a resurgent interest in applying prefabrication technology to housing.

Traditional construction techniques involve the use of timber molds or shuttering for

roof spans and other structural systems. These temporary timber structures have a short lifespan

and due to the volume of construction in the peak seasons of spring and summer for larger well-

funded projects are often unavailable. This hinders construction schedules and does not allow

projects to be completed before cooler or rainy seasons begin. However, construction does not

stop in the summer despite the lack of proper equipment and material. Instead, using makeshift

methods for construction on site leads to inappropriate means and hence a substandard quality of

construction in finished buildings. The prefabricated alternative to roof construction removes the

issues of timber molds and shuttering.

Material advances in the prefabrication housing market have also helped to mitigate

material failures. The use of fly ash in concrete increases its workability and improves thermal

performance. In addition, fly ash concrete block is beginning to replace traditional clay bricks

because it does not contain expansive soils that cause walls and floors to crack with fluxes of

temperature and humidity. Fly ash is captured from the coal burning process that generate

electricity and then reused to manufacture more durable and stable building materials in a factory

environment. The material manufacturing is more predictable and therefore serves to build more

seismically resistant structures.

Prefabrication technology has not transferred as easily when compared with other

technologies because it is a production technology or knowledge based and not a consumption

technology or product based. Technology transfer of prefabrication is not as pertinent to

architects as it is to manufacturers of building products, but we are caretakers of culture in the

AEC industry. In many cases we are asked to help with many of the transfers that are occurring

by way of global practice or working for multi-national firms that are producing prefabricated

components and entire buildings for India and elsewhere. Although transfers will continue to

occur, especially in the area of prefabrication in building, we should be well aware of how the

decisions of U.S. and western architects may have an effect on the ethical dilemmas regarding

less developed countries’ development and culture (Ref. 3).

2.4 A FEW SUCCESSFUL PROJECTS EXECUTED IN INDIA USING PREFAB

1) Project : Cluster of EWS Houses 350 Nos

Client : Karnataka Housing Board Government of Karnataka

Area of plinth: 285 sft. Single storey, 1 Hall, 1 Kitchen, 1 Bedroom and 1 Bath cum toilet

Grade of concrete: M20 Dynamic grade for wall and M20 for Roof and foundation

Shuttering : Aluminium shuttering

Cost of House : Rs. 2 Lacs

Mass Housing involves designing and building a home on the inside and maximize performance

and conserve resources. A concrete home consumes less energy, water and natural resources;

creates less waste and is healthier and more

2.5 CONCLUDING REMARKS

In order to cope with the demand for housing to fulfill the deficit in housing,

prefabrication will definitely stay once it is adopted. This may definitely improve quality of

construction, durability of components, time of construction, aesthetics of surroundings. The

next chapter gives the details of prefabrication in general and Modular Co-ordination as applied

to Pancheswar Project.