A Study of Cost Effective Materials for Low-Cost Housing

Abstract                                                             

Nowadays, the basic necessity and everyone’s dream is to have their own house with diverse needs. Housing, being a very important sector and a major contributor to the economy of the country, can be positively affected by the cost effective construction. Shortage of housing is mostly found among the low income group people and this is increasing with the continuous rise of cost of construction. The cost of construction increased by 50% over nominal inflation due to increase in cost of basic building materials and labour in a time period of 20 years due to various reasons like money inflation, increase of energy cost, company competitions, political influences, immigration etc.

Due to urbanisation there is an increasing demand for shelter. As a result, there is increase of slums in the cities and towns. The awareness on new techniques based on cost effective methods is not reaching to the public. While retaining the structural strength and aesthetics of a building, the cost of the construction can be reduced. In order to develop a national model enabling the urban and rural poor to address their housing need in such a way that the production of alternate cost effective and eco-friendly materials generate options to participate in the process of planning and implementation of their houses. Thus use of sustainable and cost effective technologies for better housing in rural and urban areas is a vital need given the increasing construction costs.

The main aim of this paper is to study the cost-effective materials which promote low cost housing.

Objectives of this research paper are:

• To examine the properties of various cost effective materials which includes physical properties, structural properties etc.
• To study the various probable use of different cost effective materials in different structural elements of a building.
• To understand different building techniques for using cost-effective materials.
• To analyze how these cost effective materials and techniques will help to create a habitable environment.
• To conclude how these cost-effective materials and techniques contribute towards low cost housing.

Keywords Cost-effective materials, Cost-effective techniques, Low cost housing, Eco-friendly materials

Nowadays, the basic necessity and everyone’s dream is to have their own house with diverse needs. Housing, being a very important sector and a major contributor to the economy of the country, can be positively affected by the cost effective construction. Shortage of housing is mostly found among the low income group people and this is increasing with the continuous rise of cost of construction. The cost of construction increased by 50% over nominal inflation due to increase in cost of basic building materials and labour in a time period of 20 years due to various reasons like money inflation, increase of energy cost, company competitions, political influences, immigration etc.

Due to urbanisation there is an increasing demand for shelter. As a result, there is increase of slums in the cities and towns. The awareness on new techniques based on cost effective methods is not reaching to the public. While retaining the structural strength and aesthetics of a building, the cost of the construction can be reduced. In order to develop a national model enabling the urban and rural poor to address their housing need in such a way that the production of alternate cost effective and eco-friendly materials generate options to participate in the process of planning and implementation of their houses. Thus use of sustainable and cost effective technologies for better housing in rural and urban areas is a vital need given the increasing construction costs.

The main aim of this paper is to study the cost-effective materials which promote low cost housing.

Objectives of this research paper are:

• To examine the properties of various cost effective materials which includes physical properties, structural properties etc.
• To study the various probable use of different cost effective materials in different structural elements of a building.
• To understand different building techniques for using cost-effective materials.
• To analyze how these cost effective materials and techniques will help to create a habitable environment.
• To conclude how these cost-effective materials and techniques contribute towards low cost housing.

Keywords Cost-effective materials, Cost-effective techniques, Low cost housing, Eco-friendly materials

Low cost housing can be considered affordable for low- and moderate-income earners if household can acquire a dwelling unit (owned or rented) for an amount up to 30 percent of its household income (Miles, 2000). In developing countries such as India, only 20 percent of the population is high-income earners, who can afford average housing units. The low-income groups in developing countries are unable to access the housing market (Tam, 2011). 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 (Tiwari et al., 1999). It should be noted that low-cost housings are not houses that constructed from cheap building materials of substandard quality. A low-cost house is designed and built 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 (Miles, 2000). 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 is a new concept which deals with effective budgeting and following of techniques which help reducing construction cost through the use of locally available materials along with improved skills and technologies without sacrificing the strength, performance and life of the structure (Kumar, 1999; Civil Engineering Portal, 2008). Low cost housing techniques aim to cut down 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.

In India, the technology to be adopted for housing components should be such that the production and erection technology be adjusted to suite the level of skills and handling facilities available under metropolitan, urban and rural conditions. (Adlakha and Puri, 2003; Low & Chambers, 1989)

Logical approach to optimizing housing solutions: There should be a logical approach to providing appropriate technology based on the availability of options, considering its technical and economic analysis.

1. There should be optimal space in the design considering efficiency of space, minimum circulation space

2. Economy should be considered in the design of individual buildings, layouts, clusters etc.

3. While preparing the specifications it should be kept in mind that, cost effective construction systems are adopted (Chowdhury & Roy, 2013).

4. Energy efficiency has gained considerable importance due to the energy crisis especially in developing countries. Orientation, built–form, openings & materials play a vital role besides landscaping / outdoor environment.

5. To develop an effective mechanism for providing appropriate technology based shelter particularly to the vulnerable group and economically weaker section (Garg, 2008).

Prefabrication, as applied to ‘Low Cost Housing (Adlakha and Puri, 2002) Advantages of prefabrication, are:

1. In prefabricated construction, as the components are readymade, self-supporting, shuttering and scaffolding is eliminated with a saving in shuttering cost.
2. In traditional construction, the repetitive use of shuttering is limited, as it gets damaged due to frequent cutting, nailing etc. On the other hand, the mould for the precast components can be used for large number of repetitions thereby reducing, the cost of the mould per unit (Cairncross, Hardoy, & Satterthwaite, 1990).
3. In prefabricated housing system, there is saving of time as the elements can be casted beforehand during the course of foundations being laid and even after laying slab, the finishes and services can be done on the slab immediately. While in the conventional in-situ RCC slabs, due to props and shuttering, the work cannot be done, till they are removed. Saving of time means saving money.
4. In prefabricated construction, there is better quality control, shape and size of precast elements. Therefore, in structural design, full advantage of properties of cement and steel can be exploited. There is disciplined the use of scarce materials like cement, steel and timber (Chowdhury & Roy, 2013).
5. In precast construction, similar types of components are repeatedly produced , resulting in increased productivity and economy in cost too.
6. In precast construction, the construction is not affected due to weather, rain, wind, etc.
7. In prefabricated construction, the work at the site is reduced to a minimum and, therefore, work is qualitatively better, more reliable and clean (Dewit & Schenk, 1989).
8. Because of faster completion and reduction in the period of construction the houses can be occupied earlier, which means early return of the investment.

According to Taur and Devit (2009), prefabrication is liked for its speedier construction, better quality components, and saving in material quantities and costs. It may be used on various parts of the house including the walls, the floor, and the roof. In each of the cases, the resulting house is low cost and presentable.

In walling, prefabrication may be used in the form of:

• Nonerodible mud plaster
• Solid concrete and stone blocks
• Fly –Ash sand lime bricks (Platt, 1997).

Some of the prefabricated roofing/flooring components found suitable in many low-cost housing projects are:

• i. Precast RC Planks.
• ii. Prefabricated Brick Panels
• iii. Precast RB Curved Panels.
• iv. Precast RC Channel Roofing
• v. Precast Hollow Slabs
• vi. Precast Concrete Panels

In the case of each of the methods above, the materials used are easy to find, and the methods used are easy to learn and implement. As a consequence, the houses built in this way are low-cost (Rao, Shivaram, & Hegde, 2012).

Another material that may be used in the construction of low-cost housing is Cuore concrete. Micro silica has been one of the world’s most widely used products for concrete for over eighty years. Its properties allowed high compressive strength concretes; water and chemical resistant concrete, and they have been part of many concrete buildings that we see nowadays. Its disadvantage, though, has been its relatively high cost and contamination, which affects the environment and the operators’ health. As micro silica, as a powder, is thousand fold thinner than cigarette smoke. Operators must take special precautions to avoid inhaling micro silica and not to acquire silicosis, an irreversible disease (Civil Engineering Portal, 2012).

In the middle of 2003, a product that could replace micro silica seen the contaminant effects, having the same or better characteristics and at a reasonable cost was on the design table. The goal: silica is fulfilling the environ-mental regulation: ISO-14001 (Pugh, 1990). Using tools from physics, chemistry, and recent nanotechnology advances, the challenge was fulfilled. Lab tests and production tests proved that the Nano-silica did not contaminate (because of its state), but it also produced better results than micro silica, and a liter bottle of the product was equivalent to a barrel full of micro silica, extra cement and super plasticizing additives (Civil Engineering Portal, 2012).

Properties of concrete with Cuore concrete nano silica

• In high compressive strengths concretes (H-70), Cuore concrete is 88% more efficient than micro silica, added to concrete and super plasticizers. ( For an average 9,43 Kg. of Cuore concrete Nano silica, 73Kg. of all the others additives are used).
• The production cost of is drastically lower than using the traditional production method or formulas.
• It has an air inclusion of between 0% to 1%
• The cone test shows that It preserves the cone shape for more than one hour. (with a relation of H2O/Cement=0.5, adding 0.5% of Nano silica of the metric volume of the cement used, it conserved a its circle shape of 60 cm for two hours, with a loss of only 5%). The nano silica has a plasticity that has been compared to the polycarbosilane technology. Therefore, the use of super plasticizing additives is unnecessary.
• High workability with reduced water/concrete levels, for example 0,2.
• Easy homogenization. The reduction of mixing times allows concrete plants to increase their production
• Depending on the cement and the formulations used for concrete (tests from value H-30 to H-70), shows that the material provides compressive strengths between 15 MPa and 75 MPa at 1 day; 40 MPa and 90 MPa at 28 days and 48 MPa and 120 MPa at 120 days (Pugh, 1990).
• Nano silica fully complies with ISO 14001 regulations regarding the environment and health. It preserves operators of the danger of being contaminated with silicosis and does not contaminate the environment.
• It successfully passed all the tests and since the beginning of this year it is being commercialized in different parts of the world (Sripathi & Lavrač, 1995).

According to Phatak, Chavan, Rathod, Nachare & Suryawanshi (2011), India is the developing country having only 20% population of higher income group. Adequate shelter is achieved through effective utilization of locally available material and techniques. The material and techniques should be durable, economical, accepted by users and not requiring costly maintained. Economy is also achieved by postponing finishing and implementing low-cost housing technology in phases. High efficiency of workers minimizes waste in design. Studies assessing the conditions of low-cost shelters have mostly focused on satisfaction levels and subjective perception of quality particularly with regard to the dwelling units or the larger neighbourhood characteristics. However, residents usually react upon their immediate environment to achieve satisfaction and make the surrounding area as their home’s and apply good management practices can also be achieved .or all people is one of the challenges faced by developing countries (Lal, 1995). Housing is a basic need. Adequate shelter for all people is one of the challenges faced by developing countries. India is currently facing shortage of about 17.6 million houses.

Cost effective technology brings down the overall cost by adopting appropriate house construction techniques. The consumption of costly materials like cement can be limited by adopting innovative designs. The buildings are designed to adore the land profile, thus optimizing the cut and fill involved (Keswani, 1997). Cost effective technology considers the climatic condition in the area, and it means that there should be variation in the application of technology and materials prescribed for the economy. The need for reinforced lintels is totally avoided by the effective use of arches and corbels. Country burnt bricks, sun-dried bricks and stabilized mud blocks are such good enough building materials (Pillai, 2011).

To resolve this shortage, the government has launched a number of housing programs so as to help in the development of low-cost houses. Even then, the impact of the government is negligible, and the numbers do not seem to be moving. The government needs to seek the assistance of other shareholders in the strive for better housing for the people who can be acquired at low cost. One way this can be acquired is through education of the masses on locally available materials that can be used in the construction of houses. Moreover, the technology required to develop the houses should make more accessible to the people. The method used in determining the best methods of constructing low-cost houses is by determining the cost and accessibility of the materials required.

References

Alanne, K., & Saari, A. (2004). Sustainable small-scale CHP technologies for buildings: the basis for multi-perspective decision-making. Renewable and Sustainable Energy Reviews, 8(5), 401-431.

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.

Miles ME (2000). Real estate development, principles and processes, Washington D.C., Urban Land Institute.

Taur, R., & DEVI, V. Low Cost Housing. TCE Consulting Engineers Ltd, New Delhi, Indiaacsge-2009, Oct, 25-27.

Adlakha, P. K., & Puri, H. C. (2003). Prefabrication Building Methodologies for Low Cost Housing. IE (I) Journal–AR, 20-34.

Tiwari P, Parikh K and Parikh J (1999). Structural design considerations in house builder construction model: a multi objective optimization technique, Journal of Infrastructure System. 5(3), pp. 75-90.

Tam, V. W. (2011). Cost effectiveness of using low cost housing technologies in construction. Procedia Engineering, 14, 156-160.

Phatak, U., Chavan, C., Rathod, L., Nachare, V., & Suryawanshi, A. (2011). Cost Effective House by Using Various Construction Techniques and Materials. IJAR, 4(4), 194-196. doi:10.15373/2249555x/apr2014/58

Lal, A. K. (1995). Hand Book of Low Cost Housing. New Age International.

Rao, P. B., Shivaram, N., & Hegde, N. S. (2012). Low Cost Housing in India. National Conference On Contemporary Civil Engineering.

Cairncross, S., Hardoy, J. E., & Satterthwaite, D. (1990). Poor die young: housing and health in Third World cities. Earthscan.

Pillai, P. S. (2011). Cost Effective Environment Friendly Technology in the context of Kerala Economy: A Conclusive Review. Civil and Environmental Research, 1(1), 15-22.

Chowdhury, S., & Roy, S. (2013). Prospects of Low Cost Housing in India. GM, 03(02), 60-65. doi:10.4236/gm.2013.32008

Dewit, M., & Schenk, H. (1989). Shelter for the poor in India. New Delhi: Manohar.

Keswani, K. (1997). The contribution of building centres to low-cost housing in India. Building Research & Information, 25(1), 50-64. doi:10.1080/096132197370606

Low, S., & Chambers, E. (1989). Housing, culture, and design. Philadelphia: University of Pennsylvania Press.

Platt, R. (1997). Ensuring effective provision of low cost housing finance in India. Bradford: University of Bradford, Management Centre.

Pugh, C. (1990). Housing and urbanisation. New Delhi u.a.: Sage.

Sripathi, I., & Lavrač, I. (1995). Strategy for low cost housing in India. Ljubljana: [I.Sripathi].