The importance of prefabricated structures – By Gurjot Bhatia, Managing Partner, Project Management Group, CBRE

Prefabrication in construction is a practice where the components needed to create a civil structure are manufactured in defined industries and the sub-assemblies or complete assemblies are transported to the site. This differs from conventional ways of construction whereby, each component is built on site with only the raw materials being transported. Prefabrication comprises of a wide range of components, from manufacturing of windows, staircase, roof tops, trusses, to manufacturing of complete building units.

In the case where the entire building is prefabricated, only the foundation is constructed on site and all other parts like walls and windows are transported to site and bolted together.

Prefabrication almost resembles the conventional buildings with added advantages over conventional construction by significantly reducing the time of construction, sustainable and better quality than conventional construction. Since the components are manufactured in controlled environment, it provides human and environmental benefits like site safety, waste reduction, improved air quality and quality management. Albeit, in case the volumes are not big, the options come with a higher price tag and limitations in terms of flexibility.

In India, Prefabricated structures came into prominence after the establishment of Hindustan Housing factory in the 1950’s (Renamed as Hindustan Prefab Limited) by the then prime minister of India, Pandit Jawaharlal Nehru. The company introduced the use of precast concrete and pre-stressed concrete railway sleepers to the Indian market as the intention was to provide immediate low income housing solutions in large volumes. It was an effective option as the units where low rise and standard in size with minimal requirement of flexibility and the price differential was 30-40% when compared to the conventional construction.

In context of Indian construction industry, prefabrication has not yet gained popularity and is not widely in practice which primarily is attributed to the following:

1) Cost still take precedence over speed to construction
2) Not many companies offering complete building solutions (apart from industrial and warehousing units)
3) Heavy transportation costs and risk of damage while in transit.
4) Careful handling of components and limitation to the size of modules.
5) Skilled labor required for assembly
As most construction work requires modifications to be done on site, prefabrication limits the option of alterations in the design scope of the building.

There is an immediate need for popularization and extensive use of prefabricated structures to increase the efficiency, quality and speed of construction. In India, due to lack of skilled labor and high transportation costs, the technology of prefabrication is not highly feasible. To overcome this, factories for prefabrication should be established at various locations within the country so as to allow accessibility for easy transportation. Further the labor should be provided with adequate training on prefabricated construction.

Quality checks should be undertaken in factories producing prefabricated components. Readily available materials need to be recognized and used to cut down the cost of construction and to make it more environment friendly. Modifications in design aspect of the building should be avoided. For this, there is a need for proper planning and efficient communication between the architect, structural designer and the builder, from the start of the project. Alternatively, to allow the scope of customization, small units should be prefabricated and bolted on site, rather than creating entire modules in factory.

Prefabrication should not only be limited to high rise residential buildings but should extend to small scale housings as well.

DISCLAIMER – The views expressed are solely of the author and Propcorner.in does not necessarily subscribe to it. Propcorner.in shall not be responsible for any damage caused to any person/organisation directly or indirectly.

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