29th November, 2008
The Hindustan Times
The Times Of India
Innovative construction technologies can not only cut costs but also maintain the quality, says
While building a house what is your topmost concern? It’s the budget. All that goes into the making of the house — designing, construction material, labour charges, fixtures and fittings, embellishments — spells money, often overshooting estimates. Yet, your house should not be anything less than the one you had always dreamed of. Is there an option to strike an ideal balance?
“A cheaper house is not just for the poor. One can cut unnecessary expenditure even while building beautiful houses,” said the legendary Laurie Baker, who pioneered low-cost housing in Kerala, way back in the forties.
Low-cost housing (LCH) is all about cutting down construction cost by using alternatives to conventional methods and inputs. It is about the usage of local and indigenous building materials, local skills, energy saver and environment friendly options.
What goes into the making of a low cost house?
Unlike conventional construction, abundant use of bricks and cement is avoided with rat-trap bond for walling. This means that a normal nine inch wall is made with invisible vertical cavities. This saves 20 percent of bricks and mortar. The cavities provide excellent thermal and sound insulation, effecting temperature difference up to two degrees between inside and outside. Putting electricity conduits through cavities saves costs in the long run too.
For the roof tension, concrete is eliminated by putting filler material like bricks, Mangalore tiles, coconut shells or moulds. Using arch foundations, pile foundation or column foundation can bring down costs by 40 percent, 25 percent and 18 percent respectively, over the normal open foundations. As the requirement of steel is less, the concrete mass required is also less. Slabs are lighter and thus the load transmitted to the foundation is also less.
Are LCH homes inferior in quality or in any way disadvantageous?
No. The technology has been validated through rigorous tests and found to be as robust as a conventionally built house is, if not more. The mass appeal for the technology in urban areas is sadly lacking.
There are two ways in which low cost and middle income housing can be implemented — either by opting for a standalone project or by making this segment a part of the larger, mixed-used development to get cross subsidy. Larger players too are getting interested in the segment now. Many integrated developments across the country have low cost housing as a part of it.
The most interesting part about this new-found interest in low-cost housing is the innovative ways in which companies are trying to cut down on construction cost while at the same time not compromising on quality.
Instead of stone aggregate, this flowing concrete with foam and air bubbles is poured into a mould to create the houses. The tunnel from construction process then speeds up activity and one can effectively build five-ten EWS houses a day using no skilled labour at all.
The technique uses no beams or columns — all the walls are load-bearing. In this process, 35% less cement is used and overall the total cost of construction is about 10-15% less than any other comparable technology. The structure will be completely earthquake proof, water proof and it is much more efficient than a brick and concrete structure, which means heating and cooling load is reduced drastically.