House Construction – Low Cost Feature
Here is a feature that the Hope House is incorporating into their construction to reduce the cost of material and to make the building efficient for a long run.
NEW DELHI: Believe it or not, researchers at Indian Institute of Technology, Madras have developed a unique method where one can construct a two-bedroom house of 800 square feet for a cost of just Rs 10 lakh.
The researchers from the civil engineering department have been working on the project for over a decade and have constructed a two-storey building to showcase the technology they developed to build rapid, cost-effective mass housing using glass fibre reinforced gypsum (GFRG) panels.
The researchers have constructed a ‘model housing apartment’ inside the IIT-M campus comprising four flats in a two-storeyed building. Interestingly, this method of construction is not only less expensive, but also less time consuming as the ‘GFRG demo building’ was constructed by the IIT team in just a month. Since 2003, the IIT-Madras research team had conducted extensive studies on the use of these panels as structural members for all components of the building, including earthquake resistant design. These panels, originally developed by RBS Australia, were intended as wall panels (‘Rapidwall’) suitable for rapid erection of walls in buildings to carry gravity loads.
The panels are made of calcined gypsum plaster, combined with special additives and glass fibres, to produce GFRG panels – 12m long, 3m high and 124mm thick (with hollow cavities). The IIT-M research group extended the application of this product for the entire building system – including floors, roofs, and staircases, thus significantly reducing the consumption of reinforced cement concrete (RCC). The team also collaborated in the indigenous development of an excellent water-proofing material, which is essential for prolonged durability of the GFRG panels, especially in the case of roofs and toilets.
The GFRG panels for the ‘demo building’ at IIT-M have come from the plant of FACT-RCF Building Products Ltd, Kochi, using reprocessed gypsum from FACT. The building has four units, making up a total built-up area of 1981 square feet – two flats with a carpet area of 269 square feet each, intended for the economically weaker section (EWS), and another two, with a carpet area of 497 square feet each, intended for the low-income group (LIG). The plans can be replicated horizontally (in plan) and vertically (in elevation) in mass housing projects. This demonstration building will also be used by another research group at IIT-Madras working on decentralized solar photovoltaic systems with Direct Current (DC) appliances, to demonstrate savings in electrical energy consumption.
Bhaskar Ramamurthi, director, IIT-M said:”The GFRG building, which is fit for occupation, showcases the efficacy of the rapid affordable construction technology developed at IIT-M, and is replicable for mass housing, vertically and horizontally. The use of prefabricated light-weight GFRG panels not only implies faster overall construction time but also a safer working environment. The cost of the construction, with all amenities, has been reduced to about Rs 1,250 per square foot.” The panels are prefabricated and cut to desired sizes based on room dimensions with openings for doors and windows, thus making rapid construction possible.
A panel has two skins of 15 mm thickness that are interconnected at regular intervals (250 mm) with 20 mm thick ribs. The cavities formed by these interconnections can be used for several purposes – filling with concrete, and laying electrical conduits and plumbing pipes. Explaining the building concept, Devdas Menon and A Meher Prasad of civil engineering department, IIT-M said: “Filling the cavities with concrete increases the vertical load-carrying capacity almost tenfold, and inserting vertical steel bars in these cavities, contributes to their earthquake resistance.
In a multi-storeyed building, the number of concrete-filled cavities and steel bars can be reduced at the higher floor levels. When used as floor slabs, reinforced concrete beams can be embedded and hidden in some of the cavities, as per the design. The overall weight of the structure and consumption of concrete comes down significantly. Conventional plastering is eliminated.”