Low-Cost Housing is a new concept which deals with effective budgeting and containing a lot of techniques that help to reduce the cost of construction through the use of locally available materials along with improved skills and technology without sacrificing the strength, performance, and life of the structure. There is a huge understanding that low-cost housing is suitable for only sub-standard works, and they are constructed by utilizing cheap building materials of low quality. The fact is that Low-cost housing is done by proper management of resources.
The building construction cost can be divided into two, namely:
- Building material cost: 65 to 70%
- Labor cost: 65 to 70%
Now in low-cost housing, building material cost is less because we make use of the locally available materials, and also the labor cost can be reduced by properly making the schedule of our work. We can reduce more costs by the selection of more efficient material or by an improved design.
Areas from where cost can be reduced are:
1) Reduce the plinth area by using thinner wall concept. Ex.15 CMS thick solid concrete block wall.
2) Use locally available material in an innovative form like soil cement blocks in place of burnt brick.
3) Use energy efficiency materials which consume less energy like the concrete block in place of burnt brick.
4) Use environmentally friendly materials that are a substitute for conventional building components like use R.C.C. Door and window frames in place of wooden frames.
5) Pre plan every component of a house and determine the design procedure for reducing the size of the component in the building.
6) By planning every component of a house, the wastage of materials due to the demolition of the unplanned component of the house can be avoided.
7) Each component of the house shall be checked whether if it’s necessary, if it is not necessary, then that component should not be used.
Cost reduction through Adhoc methods
After reading this you may have a question, What is the Adhoc method?
The Adhoc method also known as Adhoc testing is a commonly used term for software testing performed without planning and documentation, but can apply to early scientific experimental studies.
Normally the foundation cost comes to about 10 to 15% of the total building and usually foundation depth of 3 to 4 ft. is adopted for single or double store building and also the concrete bed of 6″(15 Cms.) is used for the foundation, which could be avoided. It is recommended to adopt a foundation depth of 2 ft. (0.6m) for normal soil like grave soil, red soils, etc., and use the uncoursed rubble masonry with the bond stones and good packing. Similarly, the foundation width is rationalized to 2 ft. (0.6m).To avoid cracks formation in the foundation the masonry shall be thoroughly packed with cement mortar of 1:8 boulders and bond stones at regular intervals. It is further suggested to adopt an arch foundation in ordinary soil for effecting a reduction in construction cost up to 40%. This kind of foundation will help in bridging the loose pockets of soil which occur along the foundation. In the case of black cotton and other soft soils, it is recommended to use under ream pile foundation which saves about 20 to 25% in cost over the conventional method of construction.
It is suggested to adopt 1 ft. height above ground level for the plinth and may be constructed with cement mortar of 1:6. The plinth slab of 4 to 6″ which is normally adopted can be avoided and in its place brick on edge can be used for reducing the cost. By adopting this procedure, the cost of the plinth foundation can be reduced by about 35 to 50%. It is necessary to take the precaution of providing impervious blanket like concrete slabs or stone slabs all around the building for enabling to reduce erosion of soil and thereby avoiding exposure of foundation surface and crack formation.
Wall thickness of 6 to 9″ is recommended for adoption in the construction of walls all-round the building and 41/2 ” for inside walls. It is suggested to use burnt bricks which are immersed in water for 24 hours and then shall be used for the walls.
4. Rat–trap bond wall
It is a cavity wall construction with the added advantage of thermal comfort and a reduction in the number of bricks required for masonry work. By adopting this method of bonding of brick masonry compared to traditional English or Flemish bond masonry, it is possible to reduce the material cost of bricks by 25% and about 10to 15% in the masonry cost. By adopting a rat-trap bond method one can create an aesthetically pleasing wall surface and plastering can be avoided.
5. Concrete block walling
Because of high energy consumption by burnt brick, it is suggested to use a concrete block (block hollow and solid) which consumes about only 1/3 of the energy of the burnt bricks in its production. By using concrete block masonry, the wall thickness can be reduced from 20cms to 15 Cms. Concrete block masonry saves mortar consumption, speedy construction of wall resulting in a higher output of labor, plastering can be avoided thereby an overall saving of 10 to 25% can be achieved.
6. Soil cement block technology
It is an alternative method of construction of walls using soil cement blocks in place of burnt bricks masonry. It is an energy-efficient method of construction where soil mixed with 5% and above cement and pressed in a hand-operated machine and cured well and then used in the masonry. This masonry doesn’t require plastering on both sides of the wall. The overall economy that could be achieved with the soil-cement technology is about 15 to 20% compared to the conventional method of construction.
7. Doors and windows
It is suggested not to use wood for doors and windows, and in its place concrete or steel section frames shall be used for achieving a saving in cost up to 30 to 40%. Similarly, for shutters commercially available block boards, fiber or wooden practical boards, etc. Shall be used for reducing the cost by about 25%. By adopting brick jelly work and precast components effective ventilation could be provided to the building and also the construction cost could be saved up to 50% over the window components.
8. Lintals and Chajjas
The traditional R.C.C. lintels which are costly can be replaced by brick arches for small spans and save construction costs up to 30 to 40% over the traditional method of construction. By adopting arches of different shapes a good architectural pleasing appearance can be given to the external wall surfaces of the brick masonry.
Normally 5″ (12.5 cms) thick R.C.C. slabs are used for roofing of residential buildings. By adopting rationally designed in site construction practices like filler slab and precast elements, the construction cost of roofing can be reduced by about 20 to 25%.
They are normal RCC slabs where bottom half (tension) concrete portions are replaced by filler materials such as bricks, tiles, cellular concrete blocks,. These filler materials are so placed as not to compromise structural strength, result in replacing unwanted and nonfunctional tension with concrete, thus resulting in the economy. These are safe, sound, and provide aesthetically pleasing pattern ceilings and also need no plaster.
10. Finishing work
The cost of finishing items like sanitary, electricity, painting, etc., varies depending upon the type and quality of products used in the building, and its cost reduction is left to the individual choice and liking.
The above list of suggestions for reducing construction cost is general, and it varies depending upon the nature of the building to be constructed, the budget of the owner, geographical location where the house is to be constructed, availability of the building material, good construction management practices, etc. However, it is necessary that good planning and design methods shall be adopted by utilizing the services of an experienced engineer or an architect for supervising the work, thereby achieving overall cost-effectiveness to the extent of 25% in actual practice.