Slide 1

IntroductionNow a days population is increases day by day with the time. But, the amount of land is limited. People with the increasing population have to be merged in the existing land however they can.

According to the global marketing rule, decreasing availability of any thing leads to the increase in value of the same. Here in our case, the decrement in availability of land leads to the huge increasing value of it.

Land is the one of the essential basic need for the one to live, to build home, and to get themselves sheltered. If the land would be of higher cost, then owing the home which requires the land first would become the dream only. To fulfill the dream of the common man, we have to develop the new techniques with the modified use of newly invented instruments and methods for providing HOME in considerable low rates and in that extent which can be afforded by them. Therefore the concept of the low cost housing has to be developed and properly responded by the local as well as higher authorities and privet sectors also.

Scope of the studyThe main scope of study is to reduce the cost of house and give good facilities for the buyers of that house in low cost as compare to other developed areas.

various factors affecting the low cost or affordable housing processcost of landchange of designuse of materialmethod of constructionZone of construction.satellite town concepts etc.

AimsReducing the cost of construction.

Introduction of improved construction material.

Not sacrifice any element of safety or serviceability of the house over the life cycle.

Feasibility of using the construction methods elsewhere.ObjectivesPreserving and expanding the supply of good-quality housing units.

Making housing more affordable and more readily available.

Promoting racial and economic diversity in residential neighborhoods.

Helping household build wealth.

Strengthening families.

Promoting balanced city growth.

Why affordable housing is needed ?Indian urban population in 2001 was 27.8% of the total population. Over 5 decades, annual growth of urban population ranged between 2.7 to 3.8%. During last decade it increased at annual rate of 2.7%. The process of urbanisation is marked by increasing concerntration in larger cities.It is projected that by 2041, Indias urban population will be 50%.

Expected OutcomeBy the use of low cost housing we can reduce cost of house by design, material, construction methods etc.

Various outcome of the project expected are:Optimized use of land Improved functional design of buildings.Optimized use of building materials.Rationalized specifications.Introduction and Utilization of New construction materials and techniques.We are planning for cutting the overall cost with the following criterias.Planning

Designing

Material used

Construction techniques

Optimum use of land

Zone selection

Land selection

1) PlanningFewer corners on exterior walls

Limited number of exterior corners often can be found on homes designed with cost of construction in mind. Corners increase cost of material and labour in virtually every phase of the construction process.

Due diligence when hiring a general contractor

Just about everyone is concerned about pricing. It should be noted that in the end a more skilled and more expensive builder might reduce time, mistakes, and unexpected overages. Builders have subcontractors with whom they have longstanding relationships.

Thickness of walls

Thickness of wall may drastically affect on the size of the rooms to be provided in the house.Generally 230mm thick walls are provided in the conventional housing which can be reduced to 100mm and thus considerable area can be added.

More planning less guess work

Time is money! In designing and building a new home forethought reduces lag time. Lack of information leads to increased loan interest and increased labour costs as workers wait for decisions to be made. You can improve time usage by detailed planning of the project.

Build smarter with space... Smaller house, multy-use spaces

Some of the most interesting designs are also designs with the most creative use of space.

A dining room for many will be used sparingly except on special occasions and holidays. Creating an expandable plan adjoining space that might not be used at the same time for another purpose is a great way to minimize the footprint of the dining room, while keeping it as a formal feature of your home. A desk in a kitchen area is another way to keep home organization close at hand without need a den or office. Hiding features in behind a millwork door allows the space to be defined and orderly when guests are present.

Use roof trusses wherever possible.

However, the construction cost of a framed roof can be significantly more expensive than a trussed roof when time and materials are considered. Trusses are pre-designed structural components that reduce material and framing time. Trusses usually provide a flat ceiling but can be vaulted and customized.

2) Designing

While designing the low cost house, we can consider the LOAD BEARING METHOD as the best economical design method.

In load bearing method of building construction, total load of building is taken by the main walls from the foundation to the top floor of the building.

Wall which is going to carry all the load is inserted below the ground level to be rested on the footing directly.

This wall may joined with the help of the shear walls also for transferring the loads horizontally. Why load bearing construction method..?

Reduces the construction cost and time for the columns of building.

Area used in construction of beam and column is reduced.

Repetitive construction is done more fast with this method.

Less reinforcement is used compared to convectional method hence cost regarding to that is reduced.

Most suitable method for affordable housing scheme.Newly launched Concept regarding to FSI

As per the newly planned affordable housing zones, constructors get more FSI to build up the housing scheme in the predefined zones, rather than designed FSI of underlying FSI.

Though FSI till some extent is free and after that further FSI is paid, but still it is more beneficial for constructing the low cost housing.

This concept of FSI is allowed only for affordable housing scheme.3) Material used

Material for walls:

Hollow block

Shear walls

Prefabricated walls

Economical mud bricks

Recycled waste blocks

HOLLOW CONCRETE BLOCK

The most effective material used in low cost housing is HOLLOW CONCRETE BLOK. It is used in place of bricks.

These CONCRETE BLOCKS are made by the concrete with the hollow cross section in the centre part. Which helps in reducing the total weight and improving the insulation.

Effective durability, less maintenance, insulation against sound and fire, economical rates are the fascinating advantages.Cost Difference between Brick & Hollow Concrete Block:Brick work constructionHollow concrete block constructionBrick required per cu m = 650 piecesHollow concrete block required per cu m = 103 piecePrice of 1 brick = Rs. 5=00Price of 1 hollow concrete block = Rs. 25Total price for 1 cu m = Rs. 3250=00Total price for 1 cu m = Rs. 2575=00Brick work required mortar at construction.Hollow concrete block is not required mortar.Plastering cost is added in construction cost.Plastering is not required.Material cost is high due to brick cost and plastering cost.Material cost is low due to material and plastering cost.SHEAR WALLShear wall is the concrete wall with reinforcement, which is provided at the key points of the building to resist the flexural stress coming on a building at the time of earth quake.

Shear walls are located at the building such that they make symmetry along any of two axis or along both the axis.

Normally shear walls are adopted where there are chances of earth quake and there is a need of providing structure design as per ductile detailing, though building uneconomical.

Generally shear walls are provided in L shape and have separate shaped footing of the wallPREFABRICATED WALLS

The most widely used form of prefabrication in building and civil engineering is the use of prefabricated concrete and prefabricated steel sections in structures where a particular part or form is repeated many times.

It can be difficult to construct the formwork required to mould concrete components on site, and delivering wet concrete to the site before it starts to set requires precise time management.

Pouring concrete sections in a factory brings the advantages of being able to re-use moulds and the concrete can be mixed on the spot without having to be transported to and pumped wet on a congested construction site.

Prefabricating steel sections reduces on-site cutting and welding costs as well as the associated hazards.

Prefabrication saves engineering time on the construction site in civil engineering projects.

This can be vital to the success of projects such as bridges and avalanche galleries, where weather conditions may only allow brief periods of construction.

Economical mud bricks

Following technical solutions are achieved by use of MUD BRICKS: the mud as the main raw material, supplemented hardener, construction waste, waste incineration slag aggregate material is doped materials, adding a variety of chemical and natural raw materials constitute a modifier will silt and then generate structural stability, non-toxic, harmless lump wall.

Mud brick technology requirements are high mechanical strength, good wear resistance, water resistance strong. Curing agent added several kinds of inorganic waterproofing agents and organic waterproof, fungicides, etc., to make mud bricks with high compressive and flexural strength and better water resistance, abrasion resistance.

Recycled waste blocks

Recycled waste blocks are foamed concrete building block made of waste residues of ceramics and a method for manufacturing the foamed concrete building block. Recycled waste blocks provide a powder with a ceramic waste, waste polystyrene foam as the main raw material powder of the ceramic waste foam concrete blocks, so as to solve the ceramic waste and polystyrene foam waste on the environment arising from pollution, but also to solve the ceramic waste and scrap recycling polystyrene foam resources, turning waste into treasure, for the benefit of victims, to achieve a virtuous cycle of solid waste resource utilization.

It has the advantages of light weight, high strength, environment friendliness, low cost and high benefits and is in line with the national rules and regulations about energy conservation and emission reduction, development of low-carbon economy and environmental protection.

Materials for roof and slabs.

Precast RC plank

Prefabricated brick panels

Precast RC channel roofing

Precast hollow slabs

Precast concrete panels

Filler slabsPrecast RC plank roofing system

This system consists of precast RC planks supported over partially precast joints.

There are haunches in the planks which tapered. When the plank is put in between the joists, the space above 3 cm thickness is filled with in-situ concrete to get T beam effect of the joists.

3 cm wide tapered concrete filling is also provided for strengthening the whole portion during handling and errection.

The planks have 3 numbers of 6 mm dia MS main reinforcement and 6 mm dia @ 20 cm c-c distance with maximum length of 150 cm and the maximum weight of dry panel is 50 kg.Precast RC channel roofing

Precast channels are trough shaped with the outer side corrugated and grooved at the ends to prevent sheath key action and transfer moment between adjacent units.

Nominal width of units is 300mm or 600m with overall depth of 130 mm to 200 mm. The length of units are adjusted to suit the span.

The flange thickness is 30mm to 35mm. Where balcony is provided, the units are projected out as cantilever by providing the necessary reinforcement for cantilever moment.

The saving of 14% has been achieved in actual implementation in various projects by this type of roofing.Precast hollow slab roofing.

Precast hollow slabs are panels in which voids are created by earthen kulars, Without decreasing the stiffness of strength.

The hollow slabs are lighter than the solid slabs and thus saves the cost of concrete steel and cost of walling and foundations too, due to less weight.

The width of panel is 300mm and depth may vary from 100mm to 150mm as per the span, the length of panel being adjusted to suit the span.

The outer sides are corrugated to provide transfer of shear between adjacent units.

Extra reinforcement is provided at top to take care of handling stresses during lifting and placement.

Saving about 30% in concrete cost and all over saving is about 23%.Filler Slab

The slab filled with lighter filler materials is known as the filler slab.

Filler slabs consume less concrete and steel as compared to conventional RCC slabs, due to the use of less heavy , low cost filler materials such as rejected Calicut tiles, clay pots and broken pieces of cement blocks.

The saving by the filler slabs as compared to the conventional slabs is about 22% on over all cost.Filler slab rate analysis.ItemUnitQuantityRateAmount (Rs)8mm tor steel1kg.3536.51277.5Cement1kg.2005.21040Metal1cft.2018360Sand1cft.1513.5202.5Tiles 1no.802.75220Labour & shuttering1sq.ft100101000Total =>=>=>4100Conventional RCC slab rate analysis.ItemUnitQuantityRateAmount (Rs)8mm tor steel1kg7036.52555Cement1kg3005.21560Metal1cft.3018540Send1cft1813.5243Tiles1nos10010.21020Total=>=>=>5918CONCLUSION

30% saving is possible by replacing filler slab in place of conventional RCC flat slabs.4) Construction techniques.

Cost reduction through adhoc method.

Cost reduction through noval method.

Concrete monocoque building construction.

Cost reduction through adhoc method.

FOUNDATION

Normally the foundation cost comes to about 10 to 15% of the total building.

Adopt a foundation depth of 2 ft. (0.6m) for normal soil like gravely soil, red soils etc., and use the uncoursed rubble masonry with the bond stones and good packing.

Adopt arch foundation in ordinary soil for effecting reduction in construction cost up to 40%.

In the case 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.

PlinthIt is suggested 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%.Rattrap bond wallIt is a cavity wall construction with added advantage of thermal comfort and reduction in the quantity 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 in the material cost of bricks by 25% and about 10to 15% in the masonry cost.Soil cement block technologyIt 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 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.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%.

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 the construction cost could be saved up to 50% over the window components.Lintels and chhajjas.

The 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.

RoofingNormally 5 (12.5 cm) thick R.C.C. slabs are 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 slabs

They are normal RCC slabs where bottom half (tension) concrete portions are replaced by filler materials such as bricks, tiles, cellular concrete blocks, etc. Jack arch roof/floor

They are easy to construct, save on cement and steel, are more appropriate in hot climates.

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.Cost reduction through noval method

A method and apparatus for the construction of low-cost building structure through the synergistic composition of material, process, and structural design.

In a first embodiment, a specially fashioned balloon in the shape of a house, is used as a one-sided form, and is sprayed with a building material formulation.

The building formulation with structural material, reinforcing material such as fibbers to eliminate or minimize separate structural reinforcement, a gaseous bubble material to provide thermal insulation, and other ingredients such as fillers, strengtheners, bulk-formers, accelerators, colouring agents and dryers. The structure can be created rapidly, and the balloon deflated and removed in minimum time, all by as few as two men.

The low cost of the labour and materials and equipment used according to this method result in a more economical method of creating a building than any presently known method.

Concrete monocoque building construction

A technique for forming an insulated monocoque concrete shell house, wherein the house structure is built using foamed plastic interlocking and non interlocking blocks. Once the structure is built, openings can be manually cut with ease into the wall of the structure to accommodate windows and doors.

The inner and outer surfaces of the foamed plastic block structure, as well as part of the foundation adjacent to the walls of the structure, are sprayed with concrete, forming a concrete monocoque shell house.

To form the house, a concrete foundation is formed having a ledge. The ledge spans the periphery of the foundation and defines the outer plan shape of the house. The external walls of the house are built against the ledge. The house structure is built on the foundation using foamed plastic interlocking and no interlocking blocks.

The walls of the house are built using blocks selected from a set comprising double lock, single lock, plain, hybrid, double rectangular peg and peg support blocks. Each wall interlocks with its adjacent walls.

The roof of the house is built using foamed plastic blocks which interconnect using a tongue and groove method. The roof is built from blocks selected from the group comprising of angle edge blocks, triangular blocks, curved rectangular and semi rectangular blocks, and combinations thereof.