LOW COST RESIDENTIAL BUILDING USING LOCALLY AVAILABLE MATERIALS

GROUP MEMBERS NAME• PALLAB MALLICK- 41• AKSHAY PANDEY- 46• SIDDHARTH SANKAR SARKAR-51• JAYANTA KUMAR PAUL-55• MOHIT AGARWAL- 59• PUSPENDU RAY- 61

ACKNOWLEDGEMENTWe all the group members of dis project would like to show our deepest gratitude to our respectful ‘Hod’ sir and ‘PBG’ sir for giving us a good guideline for dis project.We would also like to expand our gratitude to all those who directly and indirectly guided us.

INTRODUCTION India is the developing country having only 20%

population of higher income group. The dream of owning a house particularly for low-

income and middle-income families is becoming a difficult reality. Hence, it has become a necessity to adopt cost effective, innovative and environment-friendly housing technologies for the construction of houses and buildings for enabling the common people to construct houses at affordable cost.

For this Concept of LOW COST HOUSING is introduced in India.

LOW COST HOUSING Low Cost Housing is a new concept which deals

with effective budgeting and following of techniques which help in reducing the cost 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 huge misconception 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. Economy is also achieved by postponing finishing works or implementing them in phases.

FACTORS AFFECTING THE COST OF CONSTRUCTION

Building Cost-The building construction cost can be divided into two parts namely:Building material cost : 65 to 70 %Labor cost : 65 to 70 %

Now in low cost housing, building material cost is less because we locally available materials are used and also the labour cost can be reduced by properly making the time schedule of our work. Cost of reduction is achieved by selection of more efficient material or by an improved design.

Size-The smaller the project in terms of scope or the number of square feet, the more it will cost per square foot.

Type-Different types of project have different levels of complexity and detail

COST-EFFECTIVE BUILDING MATERIALS AND CONSTRUCTION TECHNOLOGIES RESEARCH AND DEVELOPMENT BODIES IN INDIA ARE:-

Central Building Research Institute (CBRI) Structural Engineering Research Centre

(SERC) Centre for Application of Science and

Technology to Rural Areas (CASTRA) Regional Research Laboratories (RRL) National Environmental Engineering Research

Institute (NEERI)

CONSTRUCTION TECHNIQUES OF LOW COST HOUSING:-

1) Rat-trap Bond Technology. 2) Filler Slab Technology.

3) Aluform Technology. 4) Gypsum Area Separation Wall. 5) Low Cost Materials 6) Different construction techniques in

Foundation, roofing ,ceiling etc to reduce the cost of construction.

FOUNDATION COSTS:- Normally the foundation cost comes to about 10 to 15% of

the total building . It is recommended to adopt a foundation depth of 2 ft.

(0.6m) for normal soil like gravely soil, red soils etc. It is suggested to adopt arch foundation in ordinary soils. In case of black cotton and other soft soils, it is recommend

to use under ream pile foundation which saves about 20 to 25% in cost over the conventional method of construction.

Arch foundation is used in which walls are supported on the brick or stone masonry.For the construction of the foundation, the use of available materials such as brick or concreteblocks can be made to resist lateral forces buttresses at the corner

FOUNDATION:- Random rubble masonry in

mud/cement mortar placed in excavation over thick sand bed. Rubble pointing above ground level in stabilized cement mortar.

Use of lean cement concrete mix 1:8:16 for base with brick masonry in 1:6 cement mortar footings.

Use of lean cement concrete mix as above for base and over burned bricks masonry in cement lime mortar (1:2:12) footings.

Arch foundations in place of spread foundations

Arch foundation:- This type of foundation was used in

olden times where in spread foundation is replaced by inverted arch .

It reduces the construction cost up to 40%

Advantage of this is-In soft soils that the depth of foundation can be greatly reduced; disadvantage is that the end piers have to be specially strengthened by buttresses so as to avoid the thrust to arch action tending to rapture the piers junction.

PLINTH It is recommended to adopt 1 ft.

height above ground level for the plinth and may be constructed with a 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 plinth foundation can be reduced by about 35 to 50%.

WALLING Brick work in 1:6 cement mortar using bricks

from black cotton and inferior soil stabilized with fly-ash.

Rat-trap bond brick work in 1:2:12 cement lime mortar/1:1.5:3 cement sand mortar.

Hollow concrete block masonry in cement mortar. Compressed mud blocks masonry in mud mortar. Stabilized mud blocks masonry (4% cement or

lime) in stabilized mud mortar. Sand lime brick walls in 1:6 cement mortar. FAL-G sand block with 1:6 cement mortar.

RAT TRAP BOND TECHNOLOGY The rat trap bond is a masonry technique, where the

bricks are used in a way which creates a cavity within the wall, while maintaining the same wall thickness as for a conventional brick masonry wall. While in a conventional English bond or Flemish bond, bricks are laid flat, in a Rat trap bond, they are placed on edge forming the inner and outer face of the wall, with cross bricks bridging the two faces.

The main advantage of Rat-trap bond is reduction in the number of bricks and mortar required as compared to

English/Flemish bond because of the cavity formed in the wall.

This technology has about 25% overall-saving on cost of a building of traditional 9" construction. The structure has proven its strength to go up to three floors with the support of brick columns. With this technique there is reduction in cost of the wall by 25% as with conventional English bond (9’’thk wall) 350 bricks are required per cu. m whereas in Rat-trap bond only 280 bricks are required and also the reduced number of joints reduces the mortar consumption.

BRICK JALI THE COMMON BURNT BRICK IS

ONE OF MAN’S GREAT INVENTIONS. ALL OVER THE WORLD, WITH ONLY A FEW EXCEPTIONS, NEARLY ALL BRICKS ARE ROUGHLY THE SAME SHAPE AND SIZE - THAT IS ABOUT 9 X 4.5 X 3 INCHES.

IN MANY OF THESE SITUATIONS LISTED ABOVE  A “JALI” IS JUST AS EFFECTIVE. FAR FROM BEING A LOT MORE COSTLY THAN THE BASIC WALL, IF MADE OF BRICK IT CAN BE LESS COSTLY THAN THE HOUSE WALL!

MORE USES:-

BRICK JALI CAN BE USED INSTEAD OF PARAPET WALL OR BOUNDARY WALLS...

Climate consideration and

use of local materials helps

maintaining economy than the

general rcc practice.

Instead of using regular walling

system of lintel and window system ,jali work can help cost

estimation.

MORE METHODS Soil cement block technology

this method of construction of wall is by 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 hand operated machine and cured well and then used in the masonry. The overall economy that could be achieved with the soil cement technology is about 15 to 20% compared to conventional method of construction.

Concrete block wallingIn view of high energy consumption by burnt brick it is suggested to use concrete block (block hollow and solid) which consumes about only 1/3 of the energy of the burnt bricks in its production. Concrete block masonry saves mortar consumption, speedy construction of wall resulting in higher output of labor, plastering can be avoided thereby an overall saving of 10 to 25% can be achieved.

ROOFING TECHNIQUES Normally 5″(12.5 cms) thick R.C.C. slabs is used

for roofing of residential buildings. By adopting rationally designed in situ construction practices like filler slab and precast elements the construction cost of roofing can be reduced by about 20 to 25%.

FILLER SLAB TECHNIQUEThey are normal RCC slabs where bottom half (tension) concrete portions are replaced by filler materials such asbricks, tiles, cellular concrete blocks, etc. These filler materials are so placed as not to compromise structuralstrength, result in replacing unwanted and nonfunctional tension concrete, thus resulting in economy. These aresafe, sound and provide aesthetically pleasing pattern ceilings and also need no plaster.

THE MECHANISM

The filler slab is a mechanism to replace the concrete in the tension zone. The filler material, thus, is not a structural part of the slab. By reducing the quantity and weight of material, the roof become less expensive, yet retains the strength of the conventional slab. The most popular filler material is the roofing tile. Mangalore tiles are placed between steel ribs and concrete is poured into the gap to make a filler slab. The structure requires less steel and cement and it is also a good heat insulator.

BENEFITS OF FILLER SLAB TECHNIQUE

Saving on cost The savings on cost can be from 15 per cent to 25 per cent. But designing a filler slab requires a structural engineer to determine the spacing between the reinforcement bars.

Thermal insulationThe air pocket formed by the contours of the tiles makes an excellent thermal insulation layer. The design integrity of a filler slab involves careful planning taking into account the negative zones and reinforcement areas.

FERRO CEMENT CHANNEL/SHELL UNIT

Provide an economic solution to RCC slab by providing 30 to 40% cost reduction on floor/roof unit over RCC slabs without compromising the strength. These being precast, construction is speedy, economical due to avoidance of shuttering and facilitate quality control.

JACK ARCH ROOF/FLOOR

They are easy to construct, save on cement and steel, are more appropriate in hot climates. These can be constructed using compressed earth blocks also as alternative to bricks for further economy.

MORE METHODS

Doors and windowsIt is suggested not to use wood for doors and windows and in its place concrete or steel section frames shall be used for achieving saving in cost up to 30 to 40%.Similiarly for shutters commercially available block boards, fibre or wooden practical boards etc., shall be used for reducing the cost by about 25.

Lintels and ChajjasThe traditional R.C.C. lintels which are costly can be replaced by brick arches for small spans and save construction cost up to 30 to 40% over the traditional method of construction.

OPENING IN THE FORM OF ARCH WITH LOCAL MATERIAL:-

Arches are an economical and aesthetic means of spanning openings. Arches can be a cost effective alternative to the lintels.

The traditional RCC lintels which are costly can be replaced by brick arches for small spans and save construction cost up to 30–40% over the traditional method of construction.

DOOR PANELS Plantation timber styles

with particle board inserts. Medium density fiber

board doors. Cement bonded particle

board Plantation timber style

with rice husk board inserts

Red mud polymer panel doors.

Ferrocement doors Polyvinyl chloride doors

panels.

High density fiberboard doors

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.

CONCLUSIONS The above list of suggestion for reducing

construction cost is of general nature and it varies depending upon the nature of the building to be constructed, 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.

THANK YOU