GANDHI
INSTITUTE OF TECHOLOGY AND MANAGEMENT BHUBANESWAR
A Technical Seminar Report On LOW COST HOUSING
Submitted in the partial fulfilment of the requirements for the award of the Degree of Bachelor of Engineering In Civil Engineering Submitted by Pranati,Satyabrata,Ananya,Banani Under guidance of Sanghamitra Mam Assistant Professor, Department Of Civil Engineering
GITAM
GANDHI INSTITUTE OF TECHNOLOGY AND MANAGEMENT
Department Of Civil Engineering
CERTIFICATE This is to certify that the Technical seminar entitled “ LOW COST HOUSING ” is a bonafide work carried out by Pranati,Satyabrata,Ananya,Banani
in
partial fulfilment for the award of
in
CIVI CIVIL L
ENGI ENGINE NEER ERIN ING G
BACHELOR OF ENGINEERING
of Bij Bijupat pattnaik aik
Uni Univers versiity
and Tec Techno hnology, ogy,
Rour Rourke kela la during the year 2015 2015 -2018. -2018 . The The tech techni nica call semin seminar ar repor reportt has has been been approved approved as it satisfies satisfies the academic academic requirement requirement in respect of work prescribed prescribed for bachelor of engineering.
GUIDE:
HOD
Assistant Professor
Head of Department
Department Of Civil Engineering
Department Of Civil Engineering
2
STUDENT’S DECLARATION
I,
student
of GANDHI
INSTITUTE
OF TECHNOLOGY
AND
COST MANAGEMENT , hereby hereby decla declare re that that the the semin seminar ar entit entitle led d "LOW COST
an origin original al work work carri carried ed out out by me unde underr the the guid guidan ance ce of HOUSING ”, is an MISS.Sanghamitra, ISS.Sanghamitra, assistant professor, is submitted in the the partial fulfilment fulfilment of the re requirements
for the civil engineering
of the BIJUPATTNAIK
UNIVERSITY AND TECHNOLOGY . This is a bonafide work carried out by me. The results embodied in this project report have not been submitted to any other other univer universit sity y or instit instituti ution on for the award award of any other other degree degree or diplom diplomaa certificate.
NAME: SIGNATURE
CIVIL ENGINEERING DEPARTMENT GITAM, GITAM, BHUBANESWAR BHUBANESWAR
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ACKNOWLEDGEMENT The satisfaction and euphoria that accompany the successful completion of any task would be incomplete without the mention of people who made it possible and whose constant guidance and encouragement crowned our effort with success. I consider myself proud to be a part of gitam family, gitam family, the institution that stood by my way in all my endeavours. I would like to express my gratitude to Mr.Singh Sir , principal, the GITAM college of engineering for providing me a congenial environment and surrounding to work in. I profound profoundly ly thank thank Archana Mam, Mam , Head of the Department of CIVIL Engineering who has been an excellent guide and also a great source of inspiration to my work. work . I would like to thank Sanghamitra Mam, Mam, assistant professor, civil engineering department for his technical guidance, constant encouragement and support The satisfaction and excitement that accompany the successful completion of the task would be great but incomplete without the mention of the people who made it possible with their constant guidance and encouragement crowns all the efforts with success. In this context, we would like thank all the other staff members, both teaching and non-teaching, who have extended their timely help and eased my task.
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INDEX SL. NO. 1 2 3 4 5 4
CONTENTS Abstract Introduction Housing shortage statistics Traditional construction methods Low cost construction technologies MATERIALS 1. characteristics 2. materials 1. hollow bricks 2. load bearing wall 3. precast beams and slabs 4. precast stairs
PAGE NO. 1 2 3 7 9 11
5.
Construction process
16
6
17
14
Cost effectiveness of using low cost housing technologies Advantages And Disadvantages
15 16
Conclusion References
20 21
5
19
REMARKS
ABSTRACT Adequate shelter for all people is one of the pressing challenges faced by the developing countries. India is currently facing a shortage of about 17.6 million houses. The dream of owning a house particularly for lowincome 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. This paper compares construction cost for the traditional and low cost housing technologies. Case studies in India are used for the investigation. Construction methods of foundation, walling, roofing and lintel are compared. Strength and durability of the structure, stability, safety and mental satisfaction are factors that assume top priority during cost reduction. It is found that about 26.11% and 22.68% of the construction cost can be saved by using low cost housing technologies in comparison with the traditional construction methods in the case studies for walling and roofing respectively. This proves that using low cost housing technologies is a cost effective construction approach for the industry.
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INTRODUCTION: Low cost housing can be considered affordable for low- and moderateincome earners if household can acquire a housing unit (owned or rented) for an amount up to 30 percent of its household income. In developing countries such as India, only 20% of the population are high-income earners, who are able to afford normal housing units. The low-income groups in developing countries are generally unable to access the housing market. Cost effective housing is a relative concept and has more to do with budgeting and seeks to reduce construction cost through better management, appropriate use of local materials, skills and technology but without sacrificing the performance and structure life. It should be noted that low cost housings are not houses which constructed by b y cheap building materials of substandard quality. A low cost house is designed and constructed as any other house with regard to foundation, structure and strength. The reduction in cost is achieved through effective utilization of locally available building materials and techniques that are durable, economical, accepted by users and not requiring costly maintenance. Economy is also achieved by postponing finishing and implementing low cost housing technologies in phases. High efficiency of workers, minimize waste in design and apply good management practices, can also be achieved. Low cost housing technologies aim to cut down d own construction cost by using alternatives to the conventional methods and inputs. It is about the usage of local and indigenous building materials, local skills, energy saver and environment-friendly options.
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HOUSING SCENARIO IN INDIA:
India is a populous country where approximately 70% of the people reside in rural areas. These people are migrating to urban settlements in search of jobs and better living standards. The exhibit 1 below shows the state-wise and category-wise housing shortage in India. It can be seen that 99% of the housing requirement is in the Economically Weaker Section (EWS) and the Low Income Housing (LIG) space
Estimation of Urban Housing Shortage :
About nineteen million (18.78 million) households grapple with housing shortage in Urban India (2012) as per the estimate of the Technical Group on Urban Housing Shortage. The estimate is based bas ed on Census & NSS 65th Round results on Housing conditions and Urban Slums with usual inputs like obsolescence factor, congestion factor & homeless households.
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Distribution of Housing shortage state wise:
Taking into account the fact that the shortage in housing is significant in lower income group, for 2012, TG-12 distributed the shortage on the basis of State’s contribution to the total, on the basis of average of total number of households below poverty line in urban areas & households with katcha houses in urban areas. In the past national level housing shortage was distributed among the states in proportion to number of urban households.
Distribution of Housing shortage across major States
Housing shortage across Economic categories :
Three fourths of the shortage is in the EWS (Economically Weaker Sectionincome income up to Rs 5000 per month) month) category category a n d another quarter quarter of the shortage shortage is in LIG (Lower (Lower Income Income Group- In c o me between between Rs 5001- 10,000 10,000 per month) month) category. In the latter, a significant proportion of shortage is on account of congestion in living conditions. 4
International scenario:
The figure for estimated housing shortage across the world according to the internationally recommended standards, (PPD: people per dwelling 3.5) is 428,700,000 units. However this figure is more than the double if it is calculated using Dutch standards (PPD 2.4); 1,088,219,000 units .
Key statistics: •
By the year 2030, an additional 3 billion people, about 40 percent of the
world’s population, will population, will need access to housing. This translates into a demand for 96,150 new affordable units every day and 4,000 every hour. •
One out of every three city dwellers – nearly a billion people – lives in a
slum and that number is expected to double in the next 25 years. (Slum indicators include: lack of water, lack of sanitation, s anitation, overcrowding, non-durable structures and insecure tenure.) •
As much as 70 percent of the urban housing stock in sub-Saharan sub- Saharan Africa, 50
percent in South Asia, and 25 percent in Latin America America and the Caribbean is of poor quality and not in compliance compliance with local regulations. •
Access to land is fundamental to adequate shelter. Having legal title to that
land encourages families to invest and an d improve their homes and allows 5
them to access credit and and other public services such as water and electricity. electricity. Near ly ly one sixth of the world’s population world’s population is living without secure tenure . •
The quality of housing stock & amenities directly affect health & quality q uality
of life One’s health health is directly linked to housing and housing related basics such as water and sanitation. In Mexico, researchers at the World Bank and University of California, Berkeley, found that replacing dirt floors with concrete floors improved the health of children. •
2.6 billion people or 39 per cent ce nt of the world’s population live live without
access to improved sanitation and 751 million people share their sanitation facilities with other households or only use u se public facilities. (World Health Organization, 2009)
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TRADITIONAL CONSTRUCTION METHODS: The traditional construction methods are used in the case study. The detail procedures of each step used for the case study are as follow: Foundation : Foundation is the lowest part of the structure which is
provided to distribute loads to the soil thus providing base for the superstructure. Excavation work is first carried out, then earth-work is filled with available earth and ends with watering and compaction in a 6” 6 ” thick thick layer. Cement concrete : Plain cement concrete is used to form a levelled surface
on the excavated soil. The volumetric concrete mix proportion of 1:4:8 (cement: sand: aggregate), with a 6” thick layer for masonry foundation and column footings is used. Plain cement concrete is finished on the excavated soil strata and mixed by b y manual process. Wall construction : Size stone masonry for foundation is constructed for
outer walls and burnt brick masonry of a 9” thick 9” thick layer for main walls and a 4 ½” thick ½” thick layer for all internal walls. Good quality table-moulded bricks are used for the construction. Reinforced cement concrete slab and beam : The normal procedure
to cast reinforced cement concrete slab is to make shuttering and provide reinforcement and concreting. Good steel or plywood formwork is used, with proper cover blocks between bars. Both aggregate and sand used are clean, with aggregate being being ¾” ¾” graded. After the concrete is poured, it is properly consolidated. Plastering : Plastering is used for the ceiling, inside and outside walls.
Joints are raked before plastering plastering and proper curing is ensured.
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Flooring: For the flooring purpose, the earth is properly filled and
consolidated in the ratio of 1:4:8 (cement: sand: aggregate) concrete. pass ed hydraulic Plumbing: Good quality plumbing materials are used and passed test before using it. Painting and finishing : Before the painting process, surface is prepared
with putty and primer and readymade paint is used.
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LOW COST CONSTRUCTION TECHNOLOGIES:
It is found that cost-effective and alternative construction technologies, which apart from reducing construction cost by the reduction of quantity of building materials through improved and innovative techniques, can play a great role in providing better housing methods and protecting the environment. It should be noted that cost-effective construction technologies do not compromise with safety and security of the buildings and mostly follow the prevailing building codes. The detail procedures of each step used for the case study are as follow: Foundation: 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 concrete blocks can be made to resist lateral forces buttresses at the corner. Walling: Rat trap bond technology is used in the case study. It is an
alternative brick bonding system for English and Flemish Bond. The reduced number of joints can reduce mortar consumption. No plastering of the outside face is required and the wall usually is quite aesthetically pleasing and air gaps created within the wall help making the house thermally comfortable. In summer, the temperature inside the house is usually at least 5 degrees lower that the outside ambient temperature and vice versa in winter. Roofing: A filler slab roofing system is used which based on the principle
that for roofs which are simply supported, the upper part of the slab is subjected to compressive forces and the lower part of the slab experience tensile forces. Concrete is very good in withstanding compressive forces and steel bears the load due to tensile forces. Thus the low tensile region
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of the slab does not need any concrete except for holding steel reinforcements together. Flooring : Flooring is generally made of terracotta tiles or color oxides.
Bedding is made out of broken brick bats. Various patterns and designs are used, depending on shape, size of tiles, span of flooring, and client’s client’s personal preference. Plastering :
Plastering
expenditure
on
can
finishes
be
and
avoided
on
the
walls,
frequent
its maintenance is avoided. Properly
protected brick wall will never loose its its colour or finish. Doors and windows : As door and window frames are responsible for
almost half the cost of timber used, avoiding frames can considerably reduce timber cost. Door planks are screwed s crewed together with strap iron hinges to form doors, and this can be carried by ‘holdf ast’ carried st’ carried into the wall. The simplest and cost effective door can be made of vertical planks held together with horizontal or diagonal battens. A simplest frameless window consists of a vertical plank of about 9” wide set wide set into two holes, one at the top and one at the bottom. This forms a simple pivotal window. Wide span windows can be partially framed and fixed to walls or can have rows of pivotal planks
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MATERIALS: CHARACTERISTICS OF LOW COST HOUSING MATERIALS : ENERGY EFFICIENT
Simple machines – machines – saves saves energy in production Raw Materials – derived from agro-industrial wastes and natural fibers, requires less energy in production
Products – when used in house, buildings provide better thermal comfort that results in conservation of operational energy
ENVIRONMENT FRIENDLY
Converts agro-industrial waste into alternative material for low cost
housing, thus improving waste management &
environmental protection
Utilizes local resources , Substitutes wood – wood – preserving preserving forest cover
Substitutes top soil – soil – preserving preserving soil for agriculture
EMPLOYMENT GENERATING:
Simple
machines – with
manual
handling,
increases
employment for unskilled and semi-skilled workers
Small enterprises – enterprises – can can be set up at decentralized locations Production of o f components – involves involves local people after short training
OTHER CHARACTERISTICS :
1. Easy to manufacture ,Easy affordability 2. Easy Erection/commissioning ,Faster & cheaper construction 3. Effective Waste utilization ,Energy efficient and Environment friendly 11
LIST OF CONSTRUCTION MATERIALS FOR LOW COST HOUSING:
hollow bricks
load bearing wall
precast beams
precast slabs
precast stairs
Hollow blocks substitute for normal bricks :
These types of blocks can be manufactured in situ or can be precast in manufacturing factories.
1 standard hollow block = more than 12 bricks with mortar
Cost of 1 hollow brick Rs 17 vs
Cost saved in using single block
9” wall - Rs 20 vs Rs 50 ►Rs 30
4” wall - Rs 15 vs Rs 25 ►Rs 10
cost of 1 brick Rs Rs 3
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LOAD BEARING WALLS :
vs
Load bearing structure are cheaper for normal low rise building as it requires lesser concrete and steel rods as use of structural compounds like columns are reduced unless required exceptionally.
As wall is thick, it provides thermal insulation.
Easier and requires less time to construction
Flexibility & strength is low though and it is advantage for frame structure
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PRECAST BEAMS AND SLABS :
Cast in situ is expensive as more iron rods and skilled manpower is required.
Partial pre cast system uses combination of both pre cast and cast in situ.
Use of pre cast element reduces cost
Small production factory is enough.
No heavy lifting equipment equipment are required.
No need of cement plaster.
Partial pre cast system is up to 40% cheaper than conventional cast in situ RCC floor
By using precast building materials there will be saving of: Cement consumption
45%
Mild steel rod consumption
18%
Formwork required
75%
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PRECAST STAIRS
Conventional cast in situ is expensive for low cost constructions
So, precast stairs are used ,
Riser used wil be of 8 inch and tread wil be of 9 inch.
Cheaper and quicker to construct
No form work required
Can be cantilever or simply supported
Cantilever suitable for low cost construction but simply supported more durable
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Construction Construction process of low cost houses:
FOUNDATION SOLID MASONRY BLOCKS STRIP FOUNDATION HOLLOW BLOCKS ON CORNER TO ALLOW REINFORCEMENT
PLINTH LEVEL U BLOCKS WITH HORIZONTAL REINFORCEMENT
POLYTHENE DAMP PROOF COURSE
1.5” CEMENT CONCRETE FLOORING
REINFORCEMENT AT CORNER AND AROUND OPENING
PRE CAST BEAMS
PRE-CAST SLAB WITH TEMPERATURE RODS
1” CAST IN SITU CONCRETE FLOORING
CGI SHEET OVER CIRCULATION AREA
FINISHED LOW COST SHELTER
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COST EFFECTIVENESS OF USING LOW COST HOUSING TECHNOLOGIES:
The construction methods of walling and roofing are selected for the detail cost analysis based on available resources from fr om the interviews. Table 1 and Table 2 summarise the cost analysis of the traditional construction methods and the low cost housing technologies in the case studies for walling and roofing respectively. It is found that about 26.11% and 22.68% of the construction cost, including material and labour cost, can be saved by using the low cost housing technologies in comparison with the traditional construction methods for walling and roofing respectively.. 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.
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ADVANTAGES AND DISADVANTAGES: According to analysis and real estate experts, low cost housing projects endures much risk but not less attracted. attracted.
Currently, there are many
organizations as well as companies investing their fund into this segment both inside and outside country. CapitaLandCapitaLand - one of the largest real estate Singapore companies has also established Capital Value Homes to develop cheap houses in China and Vietnam. There are also many other big b ig projects have been and are running to adapt the rising demand of customer. The increase in urbanization has led to the increase in the number of urban population. While While the average income of citizen is still low, this this has created created a huge demand for low cost houses. VIPC’s experts expect that this will be an attracted segment for investors in the future. Besides this advantage, cheap houses project still still face up many many difficulties. The biggest challenge comes from the unstable mechanism and the complicated procedures. The mechanism for social houses has still not attracted enough. Before the projects can be carried out, investors must must consume a lot of time to prepare prepare papers relating to the policies and planning from relevant authorities. Complicated construction approval process and the difficulties in ensuring the high quality but low price of these cheap apartments will cause so much trouble for investors. Based on these advantage as well as disadvantage,
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CONCLUSION
The dream of owning a house particularly for low-income and middleincome families is becoming a difficult reality. It is necessary to adopt cost effective, innovative and environment-friendly housing technologies for the construction. This paper examined the cost effectiveness of using low cost housing technologies in comparison with the traditional construction methods. Two case studies in India were conducted. It was found that about 26.11% and 22.68% of the construction cost, including material and labour cost, can be saved by using the low cost housing technologies in comparison with the traditional construction methods for walling and roofing respectively. This proves the benefits and the trends for implementing low cost housing technologies in the industry.
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REFERENCES: •
Report of The Technician Group on Urban Housing Shortage (TG-12) 2012-17, National Buildings Organization, Ministry of Housing & Urban
•
Websites of National Housing Bank & National Buildings Organization. Report on “Government Initiatives and Programme Programme for Affordable Housing”, presented in National Workshop on Pro-Poor Pro -Poor Housing Finance October 29, 2008, New Delhi conducted by Ministry of Housing & Urban Poverty Alleviation.
•
Civil Engineering Portal (2008). Cuore concrete - Nano silica, Civil Engineering Portal.
•
Kumar A (1999).
Sustainable building technology for mass application, Development Alternatives Newsletter. 9(11), pp. 1-4. [3]
•
Works Department (2002). Revised schedules of rates 2000 works department and analysis of rates, Works Department, India
•
Bmptc.org
•
Google.com
•
Wikipedia.com
•
http://www.engineeringcivil.com
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