L&T Realty, the real-estate development arm of Larsen & Toubro has a presence in Mumbai, Bengaluru and Hyderabad. Its international presence includes sales and marketing representatives in Singapore, Dubai, UK and the USA. Apart from developing L&T-owned land banks, the Company has entered into joint ventures and development agreements for some of its projects.
In partnership with government authorities, it is developing Transit Oriented Developments (TODs) at Navi Mumbai and Hyderabad. The Company’s current portfolio totals over 59 million sq. ft. across residential, commercial, mixed-use developments and TOD’s – one of the largest and the most diversified product offerings amongst the real estate entities in the country. In the short span of 5 years, L&T Realty has attained the position of market leader in the industry. This is affirmed by the fact that it has close to 50 per cent of the market share (in terms of sales) in the micro-markets in which it has a presence.
Answering With Steel
L&T designed & constructed a composite building – L&T Business Park – in Powai. With this project, it appears that structural steel is the winner & principally it makes lot of sense to maximize the usage of structural steel in future buildings.
In addition, it should be noted that the dominance of steel in the multi-storeyed building is based on tangible client-related benefits including the ability to provide column free floor spans, efficient circulation space, integration of building services, and the influence of the site and local access conditions on the construction process. For crowded city projects, speed of construction and minimum storage of materials on-site require a high level of pre-fabrication, which steel-framed systems can provide.
There is a strong demand for high quality office space. Corporate headquarters for banks and other high-profile companies require that buildings are built to high construction and environmental standards. Investment ‘value’ is the main criterion for choice of the building architecture, form and servicing strategy.
I joined L&T in September 2010 as project manager engineering and this was my first project. I was very fortunate to get an opportunity to work on this project, keeping in view the ahead of time technology (composite in 2007-08) was used by L&T in commercial building. The true success of this project is in the state-of-the-art composite design facilitating large column free spaces along with the optimized floor to floor height, optimized façade system, bridge connecting both the wings and a helipad at the top. The quality of work during the construction and the safety standards followed were typically in line with what L&T is known for.
SUNIL GODBOLE, Senior DGM, Structural Engineering, L&T Realty
Built to Suit Requirement
L&T Business park was designed and constructed in 2008-2010 as a composite building. During those days, Mr. Sunil Godbole was working with L&T as Project Manager Engineering. The first customer for this building was J P Morgan Chase (JPMC) – one of the leading banks across the globe and Sunil had an important role to play. Not only he helped and supported JPMC to understand this building in detail, but, also checked that the design modifications which were brought in by JPMC are feasible or otherwise.
On top of this, it was L&T’s responsibility to hand over the JPMC premises within the aggressive timelines after the completion of the modification work. In short, it was a challenging work where the already constructed building was converted into a kind of built-to-suit for JPMC. There were many modifications suggested by JPMC and L&T, was successful in implementing most of them which were necessary for the operations of JPMC. Generally, it is perceived that it is difficult to carry out modifications in a structural steel building, however, L&T with their innovative design team – managed to incorporate most of the modifications which were desired by JPMC, without affecting the safety & stability of the building.
L&T Business Park houses two towers – Tower A and Tower B which are designed and constructed as G+10 composite steel buildings with two basements which are constructed with conventional RCC elements. The total built up area of L&T Business Park is 8 lakh sq. ft. Tower A and Tower B are connected on sixth floor with a structural steel bridge. Both the wings are identical with a central core of RCC shear walls and approximately 13m column free span.
A wing also consists of a helipad on the terrace which also has been designed and constructed using structural steel. The structural system consists of composite columns, vermiculated steel beams with composite deck slab with shear connectors.
Initially this building was designed as RCC building, however, the anticipated completion date was not in line with the L&T business plans. Therefore, the building design was changed to composite design when the basement work was in progress.
This generated great amount of pressure on the designers however, the designers ensured that the designs and drawings are made available to project team well in advance and that too after checking the material availability in the market. Here, we need to remember that we are in 2007-2008 when the structural steel commercial buildings were at very nascent stage in India.
The salient features of this project are:
- Large column-free spaces
- Excellent head rooms
- Composite helipad
- Connecting steel bridge
- Optimized façade
- 32,000 sq. ft. of cafeteria etc.
Against All Odds
Structurally this project is extremely unique keeping in view the usage of composite technology when the entire construction world in India believed that the concrete is the answer to all the questions however, we observed that the speed, quality and cost (considering the time value of money) was much better than the conventional RCC building.
In many large commercial buildings, a two-stage construction process means that the tenant is responsible for the servicing and fit-out, and so the building structure has to be sufficiently flexible to cope with these differing requirements. Many smaller buildings are designed for natural ventilation and with a high proportion of renewable energy technologies built into them. Many solutions are possible using steel construction.
The commercial sector demands buildings that are rapid to construct, of high quality, flexible and adaptable in application, and energy efficient in use. Steel, and in particular, composite construction has achieved over 70 per cent market share in this sector in the western world where the benefits of long spans: speed of construction; service integration; improved quality; and reduced environmental impact are widely recognised.
The overall building economics are fundamental on the rationale for using steel construction in the commercial building sector, where the market share for steel in western countries has been consistently 65 to 70 per cent for the last 20 years.
Recent cost comparison studies show that the building superstructure generally accounts for only 10 to 15 per cent of the total building cost and that the influence of the choice of structure on the foundations, services and cladding costs is often more significant. For example, a reduction of 100 mm in the ceiling to floor zone can lead to a 2.5 per cent saving in cladding cost (equivalent to 0.5 per cent saving in overall building cost).
Therefore, best practice building design requires a synthesis of architectural, structural, services, logistics and constructional issues. Where this synthesis has been achieved, long-span steel systems with provision for service integration dominate commercial building design.