Low cost housing deals with effective budgeting and the following techniques which help in reducing the cost construction through the use of locally available materials along with improved skills and technology without sacrificing the performance, life of the structure, and strength.
The cost of building construction is divided into two parts such as;
Building material cost as 65% to 70%
Labor cost as 65% to 70%
Building material cost is less because we make use of the locally available materials in low cost housing and by properly making the time schedule of our work, the labor cost can be reduced. By selection of more efficient material or by improved design, the cost of reduction is achieved.
Areas From Where Cost Can Be Reduced:
There are the following areas from where cost can be reduced in low cost housing such as;
By using the thinner wall concept plinth area is reduced.
In low cost housing, use locally available material in an innovative form like in place of burnt bricks use soil cement blocks.
Use energy efficiency materials which consume less energy like in place of burnt brick use concrete block.
Use environmentally friendly materials like use R.C.C door and window frames in place of wooden frames which are substitutes for conventional building components.
For reducing the size of the component in the building, preplan every component of a house and rationalize the design procedure.
The wastage of materials due to the demolition of the unplanned component of the house can be avoided by planning each and every component of a house.
There are the following components from where cost can be reduced in low cost housing such as;
Usually, foundation depth of 3 to 4 ft is adopted for single or double store building and also the concrete bed of 6 inches for the foundation which could be avoided because cost comes to about 10% to 15% of the total building from a foundation.
So, for normal soil like gravel soil, red soils, etc it is recommended to adopt a foundation depth of 2 ft and with the bond stones and good packing use the un-coursed rubble masonry. The masonry shall be thoroughly packed with cement mortar of 1:8 boulders and bond stones at regular intervals to avoid cracks forming in the foundation.
For effecting a reduction in construction cost up to 40% it is further suggested adopt arch foundation in ordinary soil and it is recommended to use under ream pile foundation which saves about 20 to 25% in cost over the conventional method of construction in the case of black cotton and other soft soils.
For the plinth, it is suggested to adopt 1 ft height above ground level and with cement mortar of 1:6, it may be constructed. For reducing the cost the plinth slab of 4 to 6 inches which is normally adopted can be avoided.
About 35% to 50% the cost of plinth foundation can be reduced and for enabling to reduce erosion of soil it is necessary to take the precaution of providing impervious blanket like concrete slabs or stone slabs all around the building.
For adoption in the construction of walls all-round the building the wall thickness of 6 to 9 inches is recommended and for inside walls, it is 41/2 inches. So, it is suggested to use burnt bricks which are immersed in water for 24 hours, and for walls, it shall be used.
Concrete Block Walling:
In low cost housing, it is suggested to use concrete block which consumes about only 1/3 of the energy of the burnt bricks in its production and the wall thickness can be reduced from 20 cms to 15 cms by using concrete block masonry.
In this plastering can be avoided thereby an overall saving of 10 to 25% can be achieved and concrete block masonry saves mortar consumption and speedy construction of wall resulting in a higher output of labor.
Soil Cement Block Technology:
Soil cement blocks are an different method of construction of walls and are an energy-efficient method of construction where soil mixed with 5% with cement and pressed in the hand-operated machine and then after curing it is used.
On both sides of walls, this masonry does not require plastering and as compared to the conventional method of construction the overall economy that could be achieved with the soil-cement technology is about 15% to 20%.
Doors and Windows:
For doors and windows, it is suggested not to use wood and for achieving saving in cost up to 30% to 40% concrete or steel section frames shall be used.
For reducing the cost by about 25%, commercially available block boards, fiber or wooden practical boards, etc shall be used and the construction cost could be saved up to 50% over the window components.
To save construction costs up to 30 to 40% over the traditional method of construction in low cost housing the traditional R.C.C lintels which are costly can be replaced by brick arches for small spans.
A good architectural pleasing appearance can be given to the external wall surfaces of the brick masonry by adopting arches of different shapes.
For the roofing of residential buildings normally 5 inches, thick R.C.C slabs are used and in low cost housing, the construction cost of roofing can be reduced by about 20% to 25% by adopting rationally designed in-situ construction practices like filler slab and precast elements.
The finish work cost reduction is left to the individual choice and liking and finishing work items like sanitary, electricity, painting, etc vary depending upon the type and quality of products.
The low cost housing depends upon the nature of the building to be constructed, the budget of the owner, good construction management practices, availability of the building material, geographical location where the house is to be constructed, etc.
By utilizing the services of an experienced engineer or an architect for supervising the work it is necessary that good planning and design methods shall be adopted in low cost housing.