Prefab Concrete: Moulding a Success Story
The Indian prefabricated component industry although is in a nascent stage, is fast catching attention of builders and construction companies. Even a fraction of upcoming investments in real estate and infrastructure project is spent in using prefabs would add about Rs 20,000 crore of business to the industry in next five year, from the current level of less than Rs 2,000 crore, that's 10 times, finds
Historically, houses have been built in one place and reassembled in another and possibly the first recorded prefab house was the manning portable cottage constructed by a London carpenter, H Manning. He constructed a house that was built in components, then shipped and assembled by British emigrants. Another interesting building was the prefabricated hospital that the British Army deployed in 1855 during the Crimean War designed by Isambard Kingdom Brunel with innovations in sanitation, ventilation and ria flushing toilet.
The world's first prefabricated, pre-cast panelled apartment blocks were pioneered in Liverpool. A process was invented by city engineer John Alexander Brodie, whose inventive genius also had him inventing the football goal net. The tram stables at Walton in Liverpool followed in 1906. The idea was not extensively adopted in Britain, however was widely adopted elsewhere, particularly in Eastern Europe.
Prefabricated homes were produced during the Gold Rush in the United States, when kits were produced to enable Californian prospectors to quickly construct accommodation. Homes were available in kit form by mail order in the United States in 1908.
"Prefabricated" refers to building built in components (eg, panels), modules (modular homes) or transportable sections (manufactured homes). Modular homes are created in sections, and then transported to the site for construction and installation. These are typically installed and treated like a regular house. Although the sections of the house are prefabricated, the sections, or modules, are put together at the construction much like a typical home.
In India, the prefabricated or precast material industry is in a nascent stage. It is worth Rs 1,500 crore in infrastructure construction and less than Rs 500 crore in case of prefabricated homes. People are experimenting with them and some contractors specialise in them although there are certain drawbacks to the support system in urban area. At present, precast technology are more in vogue in rural India and not so favourable for elite housing as aesthetics may be compromised.
However, of late, many builders have taken up prefabrication to meet demand. Earlier used in large projects, this system is gradually being preferred in most aspects of construction. Facing a shortage of labourers, builders are resorting to new ways to meet the unpreced
ented construction demand in one of the fastest growing property markets in Asia. Prefabricated building systems that have been traditionally used in India to build bridges, metro rails and industrial units so as to save money and time are now finding their way into constructing homes.
Says a structure consultant, that using prefabricated materials has made construction work easy and it also brings down the construction time by as much as 50 per cent. Though using such materials is more common abroad, prefabricated structures are used in India in only large construction projects.
Use of prefabricated materials has more or less become a norm in building construction in markets overseas. The trend has just started in India, because of the construction boom and western architectural influences.
Now, more and more builders are opting for prefabricated materials to put together large structures without employing large labourers. Prefabricated materials are essentially ready-to-fit materials manufactured at a factory outside the construction site. They are later assembled at the construction site by masons and joiners.
In prefabricated housing construction, only the foundation and floor slabs are constructed the conventional way, which involves brick work, timber work, cement and sand to the building site. Sections of walls and roof are fabricated at a factory-with or without windows and door frames attached - and transported to the site, where they are just assembled and bolted together.
Prefabrication saves time and as a result cost. For instance, casting of a super structure, where the structure of a building above the ground level takes 7-28 days if the casts are made at the construction site. But if the casts are made at a plant outside the construction site, it takes just seven days.
Although prefabrication is being used on a growing number of projects, most construction work is still site-based.
Players in Prefabricated components
The cement prefabricated component industry is largely fragmented with large number of small players dominating regional business. Many producers still continue with conventional methods of production that meet local demand and specifications. Few organised players using modern technology are emerging with modest investments in plant and machinery. Couple of them also have technical tie-up with foreign specialists. Among the major players having pan-India presence is NCL Industries.
NCL Prefab a division of NCL Industries, was set up in 1979. The company's manufacturing unit is located at Jeedimetla, Hyderabad. NCL has developed its prefab housing systems by using Bison Panel. These systems are mainly used in farmhouses, dwelling houses, row houses, project houses, custom-made houses, rest houses, guest houses, hill resorts, store sheds, penthouses, security cabins, mobile check-posts, industrial sheds, disaster housing, defense barracks, school buildings and many more. Office quarters for Reliance Petroleum staffs, guest houses for Sanghi Industries in Hyderabad, office building for Arvind Mills in Ahmedabad, hill resort at Kodaikanal and a four-storey school building in Pune are some of the projects undertaken by the company using this technology.
The company feels that the prefab business has really caught on, as most construction companies, army, as well as paramilitary forces, have started using them on a regular basis. While announcing the 2010-11 third quarter results
K Ravi, MD of NCL Industries
, stated the that company will take up construction of prefab structures in a joint venture with Austria's VST namely, NCL VST Infra Limited. The idea is to introduce the prefab technology in India, particularly for high rise buildings. The cost of the project is estimated at Rs 21 crore and the first unit will come up in Hyderabad. Later on it will spread the technology throughout the country.
The current technology limits the operations to cater to ground floors and manufacturing normal prefab shelters. Using new technology known as the formation; the shuttering material will remain in the building.
Prospects and challenges
The current cement prefabricated component industry size estimated at Rs 2,000 crore, although in a nascent stage, is fast catching attention of builders and construction companies. The size has potential to grow 10 times even if a fraction of upcoming investment in real estate and infrastructure projects is spent in using prefabs. The potential sectors which can use prefabricated component are roads and bridges, railways, airports, ports, warehousing and storage housing and commercial complexes. As of end-May 2011, total investment in pipeline in these sectors was about Rs 32,400 billion. Even 0.6 per cent of this can bring in additional business of Rs 200 billion for the prefab industry. High potential segments are roads and bridges, railways, airports and ports. These four can generate more than Rs 150 billion of business alone. However, much would depend on quality of products offered, meeting specifications and timely delivery as these projects are time and cost conscious.
NCL's improved prefab systems
The wall panel height is increased to 9 feet & 10 feet.
Expanded polystyrene sheets are sandwiched between double skin panels for better thermal comfort
Each panel is lipped on all sides with appropriate GI sections for easy interlocking. The lipping provided is helping to avoid damage of the edges during transport False ceiling is introduced for all most all the models
The roofs are provided with GI corrugated sheets or pre-painted sheets with appropriate ridge elements
Designed eve plates are introduced at the edges of the roofs to add elegance to the shelters
Electrification for lighting and air conditioning is stream lined in the system
The system of erection is simplified using minimum components