Prefabrication is an age old concept, which has been in construction world since Roman Empire. Popularity of prefab increased due to its requirement in market and the main causative are requirement of energy efficiency, wastage production reduction, requirement of wastage recycling, cost reduction, and time efficiency. The other advantages, which have been discovered shortly due to its advancement, are Its superior quality, expandability, durable, lesser maintenance, less wastage, greater sustainability, easy integration with existing building. However, few limitations also attached with this technology are transportation cost and some design limitations. However, prefab changed the way construction world was perceived but it still has not been able to replace conventional methods due to various reasons.
PREFABRICATION EVOLUTION AND ADVANCEMENT
During mid 90s with advancement in technology evolution in prefab also took place. Development of 3d printing carved out a longer and better way for successful future of prefabrication.softwares like cad,cam and bim helped prefab to climb its stepping stone of success ,which ultimately marked out its place in construction industry. Today, there have been many examples of milestones achieved by prefab with its evolution taking place , to name some examples are HSBC bank by Fosters,Nagakin capsule tower by Akira kurokawa. Prefab in western world flourished rapidly after World War II due to requirement of homes for battle returned soldiers. But with passing time and “repetitions” its has already reached its saturation point as many have started believing that prefab acts as a tool for mass production which leaves no room for new creativity and architectural aesthetics, therefore outside India many western countries have already started considering prefabrication as not the “first preference” due to deviation from “true architectural vocabulary and designs”..
PREFABRICATION IN INDIA
Prefabrication in India came post independence when pundit Jawaharlal Nehru wanted mass housing for migrants from Pakistan. Initially concrete panels have been used majorly but with new technologies coming in lots of other materials have been invented and are being used apart from concrete panels, like honey comb plastic, puff panels. There has been innovation in concrete too, GFRC, hollow concrete blocks, autoclaved aerated concrete are few examples. Prefabrication in India was started with establishment of HPL (Hindustan prefab limited) in 1955 previously known as Hindustan housing factory ltd, railway sleepers have been their prefabricated product, they were the first to deliver the first and the finest projects of prebrication in India e.g. Ashoka Hotel, NATRSS.
Since 2004 post privatization of major sectors like construction too, private companies have taken up the front seat. Main players in the market are ABRE, JINDALS PREFAB, PRECA. However, HPL recently came up with their SWATCH BHARAT programme where they proposed prefabricated toilets with the help of their demo, they have also built multipurpose prefab shelters in leh ladakh (J&K) for NDMA, considering the extreme weather condition and seismicity of that area. few examples of HPL have been listed below.
- SOLAR COLONY,LEHon 19th November, 2010, expandable prefab houses with 170 no. of rooms at Solar Colony, Choglamsar, Leh (J&K) have been completed within 41 days and have been handed over to the beneficiaries through District Administration, Leh.
- PREFAB HOUSES IN LEH-LADAKH
Prefabricated houses have also been constructed in 24 locations spread in inaccessibleand difficult areas in Leh-Ladakh region in the sub-zero temperature.
• DOME STRUCTURE AT SOLAR COLONY
Future of prefab is still a puzzling question as its application has grown widely covering almost all sectors mainly housing and commercial but with situations where client keeps on changing design, unawareness amongst general public and lack of skilled labor, and sites with largely varying contours ,prefab as the one of the “main player” in construction is still very doubtful scenario in India.
DIFFERENCE BETWEEN PREFABRICATION CONSTRUCTION METHOD AND CONVENTIONAL METHOD.
The basic differences between conventional and prefabricated construction methods area:
• Waste is managed and recycled in prefab
• Precision is taken care of .
• Prefab is less time taking
• Prefab is maintenance free
• Cost of construction reduces with modular process happening in prefab ,while its quite high.
For non-modular construction here conventional wins the race.
• Once set design cant be changed in prefab since all electrical drawings are prepared before sending drawings for manufacturing.
PREFABRICATED CONCRETE CONSTRUCTION AND AESTHETICS:
The misconception regarding prefab is its design limitations, its like placing all the skyscrapers under one vertical design element. Prefab can provide with aesthetically good design. There are various techniques through which this can happen, that area:
- Varying aggregate and matrix colors,
- Varying size of aggregates
- Finishing processes, and depth of exposureVarious tones surface finishes can be provided by mixing different pigments in concrete mixture
Detailing, joints, flashing, and maintenance costs can be easily reduced by combing multiple finishes within a single panel. Few other design techniques are mouldings and wall cladding.
ADVANTAGES AND LIMITATIONS IN PREFAB
• Superior quality
• Higher flexibility
• Expandability and phase wise construction
• Much better return on investment
• Unmatched safety
• Minimal site disruption
• Lesser maintenance
• less wastage greater sustainability
• Easy integration with existing building.
• A single prototype cannot be worked out for all sites, since every site has its own site context.
• Major problem lies with transportation in prefab when structure and panels are being manufactured off site.
• Loss of architectural detailing and creativity, which gives identity to every building.
• A single minor miscalculation or mistake can lead to big blunders at site .eg, parking garage at Miami, Florida.
Hindustan Prefab Limited Official Website