The power of steel
In India, structural steel has traditionally been fabricated on-site, mainly due to lack of infrastructure for transporting heavy sections from an off-site workshop to project site. Moreover, there is often insufficient space at a site to set up a fabrication workshop, while inexpensive skilled labour is at a premium. These issues can always be mitigated by pre-engineered buildings, which are fabricated in a workshop elsewhere.
Though the Indian model for the fabrication of structural steel differs from the model followed by developed countries, the trend is slowly but surely changing. India is now gradually moving away from onsite fabrication to workshop delivery models, which are proving to be more efficient in terms of quality and timelines, says SK Kodandaramaiah, CEO of Sunil HiTech Engineers. This helps to reduce the time and cost of execution, and is expected to fuel the demand for steel structures in India.
“The onsite fabrication model was deeply ingrained in the system because until about a decade ago, all large infrastructure projects were directly under the government, which played the role of owner, developer, designer and even EPC contractor,” he said. After liberalisation, changes came largely through the entry of private companies into the sector. The speed of execution has quickly become critical for the industry.
Rohit Choudhri of JSP agrees that the sector is seeing a “natural progression” towards the increased use of pre-fab in construction. “Until 2003, the choice of sections was restricted to what SAIL was manufacturing by using old-calibre rolling technology. However, private players employed more universal rolling technologies, resulting in the availability of a wider range of products with variation both in terms of size and depth.”
Today, a team planning a project has a wider variety to choose from as more players deliver products with the necessary dimensional tolerances. Increasingly sophisticated software is also available for pre-fab planning.
However, the shift has to be driven by changes at the top — in the mindset of owners and principal consultants, Choudhri feels: “If a project is conceptualised well and orders are placed after accurate homework, then 100 per cent of erectable parts will be delivered to the site, resulting in significant time savings,” adding that, in the case of a mega power plant, for example, this can mean cost savings of at least a few crores.
Kodandaramaiah is finding that the entry of the private sector has already begun to impact cycle times. “Everyone wants faster execution,” he says. “Now projects that took 60 months to complete a few years ago are being executed in 30 months.
“Time pressure will propel the industry towards offsite fabrication, and owners and consultants will realise the advantages in terms of uniformity of finish and better quality, as steel producers learn to align their rolling sections to design needs.”
India’s per capita consumption of steel structures is currently 6-7 kg, and this has been growing at a CAGR of over 10 per cent over the past five years. “This market is witnessing higher growth compared to both Indian steel and Indian construction GDPs. The overall per capita consumption of structural steel and pre-engineered buildings (PEBs) for India over the next ten years has the potential to look even more attractive, with the overall indicative potential reaching 17 to 22 kg per capita,” an industry report revealed.
The industrial and infrastructure segments are currently the two main contributors to the overall demand for steel structures in India. Structural steel is the default material used for the construction of plant superstructures, and the steel industry is a key demand driver within the segment. Oil and gas, petrochemicals, cement and fertilisers are also responsible for boosting demand for structural steel, which also remains the default material within the power sector, driven by huge investment and capacity additions in new power plants and transmission towers. Increased government spending in the infrastructure segment, estimated to the tune of $1 trillion over the next five years is expected to result in massive demand, especially from air- and sea ports, railway stations and bridges, and metro rail.
Structural steel is being selectively used in the construction of high-rise buildings — with three to four projects using steel or composite structures being built each year in India, mainly in metropolitan cities that are constrained by limited land availability. Concrete still remains the default construction material in the building segment in India, but industry reports suggest that the share of the building segment is expected to increase the overall demand for steel structures now that developers are beginning to recognise the benefits of structural steel. Fabricators and developers are now seeing the advantages of using structural steel over RCC, and this has resulted in a slow but gradual shift in preference towards structural steel within the building segment.
“There is a recent trend for using metal buildings as an option for affordable housing. These are typically small metal buildings, complete with civil foundations and electrical, plumbing and drainage solutions,” a research paper on structural steel by Deloitte said.
Steel is also extensively used for pre-engineered buildings, which is fast gaining popularity due to relatively simple and standard designs; the demand for PEBs in India is expected to be driven by the logistics and retail sector. Emerging as a strong alternative to conventional concrete construction methods, PEB is validated by a 33 per cent market share in the construction industry. “While this figure is lower than in some European countries, it marks India’s growing global market share at 9.5 per cent — a step ahead of China’s 8.5 per cent. The market demand is pegged at 425,000 TPA with 15 per cent growth per annum,” said a spokesperson from Kirby Building Systems India.
According to some estimates, the current market size is around Rs3,500 crore and it is expected to grow at 10 to 15 per cent each year.
“As far as India is concerned, pre-engineered steel systems are being used for most industrial projects and warehousing, ports development, automotive plants and airport terminal buildings and multi-storey buildings,” said Gautam Suri, CTO and founder of Interarch Building Products.
Emerging trends for applications include multi-level structures, such multi-storey car parks, commercial buildings, hospitals and malls. Also PEB is trying to find space in sectors like infrastructure, ports and power plants, which earlier used fabricated steel.
“Multi-storey pre-engineered buildings or steel-frame skyscrapers eliminate the inefficient part of a shear wall — the central portion — and consolidate the support members with a much stronger material: steel. This enables the building of a skyscraper with both horizontal and vertical supports,” says Amit Bharana, president of ERA Buildsys.
According to Bharana, tube frame structures use the concept of a three-dimensional space structure composed of three, four or possibly more frames joined at or near their edges. The tube units can take a number of shapes and be bundled together in different sorts of groupings. Though India has a very short history of making high-rise buildings, the immediate need of this concept has expedited development in this regard.
The penetration of PEBs in factory buildings is increasing, as the manufacturing sector and many small-scale industries are recognising the advantages of using PEB over conventional concrete building.
“The residential market is also catching up with light building systems and solutions, and pre-engineered light-gauge steel is being used for making more villas, farm houses, roof-top extensions and ground-plus-two buildings. The global market is moving towards the adaptation of sustainable construction, and with steel being a green material, it is the preferred choice for every kind of construction,” says Suri.
Unlike steel structures, PEBs are generally fabricated at workshops. In the case of PEBs, certified builders erect the various modules of the building, which are supplied by the PEB manufacturer, on-site. This method helps in speedy delivery at the lowest cost. Normally, the design is done in-house or could be provided by the project developer or structural consultant to the fabricator.
Green is an industry buzz word and companies are trying to ensure that their factories are using environment friendly materials, so most PEB players are offering green products so they can become a preferred choice over traditional ones.
“The green building concept is yet another innovative and eco-friendly option of steel construction, which encourages sustainable design. These buildings help mitigate energy consumption because they are strategically designed and use recyclable products,” said Bharana of ERA.
Steel-framed buildings tend to incorporate designs that assist proper airflow and temperature controls. Even after demolition, such buildings don’t accumulate wastage like asphalt shingles, concrete, bricks and dust. Aluminium and steel can also be recycled for other applications too: pre-engineered buildings are 70 per cent recyclable and steel is almost 90 per cent recyclable. “Using pre-engineered material results in a much better end-product and a higher LEED or green building rating per project. Our pre-engineered steel structure and roofing systems in the new Indira Gandhi International Terminal 3 building in New Delhi have helped the project earn a platinum LEED rating” says Suri.
Despite good response from a variety of new sectors, the PEB industry in India still faces its challenges, and among these is the pace of acceptance. Perception by the end-user and architects presents a barrier to accelerating the pace of building steel projects. Moreover, Indian building codes and design philosophy are still conservative and require time to adapt more homogenously to pre-engineered steel design.
And then there is cost. “Steel price rises will affect the market as well, however we are confident that this is only a temporary limiting factor to buy in towards a steel building. As the complexity and nature of building in a mega city or country like ours increases, the need to have simple and efficient projects that complete faster, and will automatically want to use more pre-engineered and manufactured systems of construction that require less space time and mess,” says Suri.