electives report on low cost housing

8/12/2019 Electives Report on Low cost Housing

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ARCHITECTURAL PROJECT1

PAPER REVIEW

TOPICLOW COST HOUSING

REPORT BY

MONALI D. BHAGAT

ROLL NO.- 06

FOURTH YEAR B. ARCH

D.Y.P.C.O.A.


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WHAT IS LOW COST HOUSING?

Low cost housingis a term used to describe dwelling units whose totalhousing costs are

deemed "affordable"to those that have a median income. Although the term is often applied

to rental housing that is within the financial means of those in the lower income ranges of ageographical area, the concept is applicable to both renters and purchasers in all income

ranges.

Housing costs considered in this guideline generally includetaxes andinsurance for owners,

and usually include utility costs. When the monthly carrying costs of a home exceed 3035%

of household income, then the housing is considered unaffordable for that household.

(InIndia,70% of the population lives below the poverty line and there is huge demand for

affordable housing.A lot of developers are developinglowcost and affordable housingfor

these population. The Government of India has taken up various initiatives for developing

properties in low cost and affordable segment.)

IMPORTANCE OF LOW COST HOUSING..

When housing is affordable, low- and moderate income families are able to put nutritious

food on the table, receive necessary medical care, and provide reliable daycare for their

children.

Research has shown that the stability of an affordable mortgage or rent can have profound

effects on childhood development and school performance and can improve health outcomes

for families and individuals.

Low-income families tend to spend their residual income to fulfill.

Residual income is the income left over after paying for housing, transportation, and utilities

the three items in the budget that are most infl uenced by where one lives.

The net gain for the local economy is maximized when the source of the housing subsidy is

non-local (i.e., federal/state government or philanthropic) in nature.

WHO BENEFITS FROM AFFORDABLE HOUSING...

When it is well developed and managed, affordable housing offers many benefits, to the

community, developers and residents.

Community:

The community benefits from affordable housing because it contributes to sustainable and

dynamic local communities, by:

providing housing for a diverse local workforce providing direct economic benefits to the local community, including increased demand for

goods and services which in turn provides increased local employment opportunities

accommodating people with the different skills required to support communities, such asshop assistants, bus drivers, construction workers, cleaners, nurses and teachers

meeting the needs of the growing number of smaller households living in high-cost areas
http://en.wikipedia.org/wiki/Househttp://en.wiktionary.org/wiki/affordablehttp://en.wikipedia.org/wiki/Taxhttp://en.wikipedia.org/wiki/Insurancehttp://en.wikipedia.org/wiki/Indiahttp://en.wikipedia.org/wiki/Low_costhttp://en.wikipedia.org/wiki/Low_costhttp://en.wikipedia.org/wiki/Low_costhttp://en.wikipedia.org/wiki/Low_costhttp://en.wikipedia.org/wiki/Indiahttp://en.wikipedia.org/wiki/Insurancehttp://en.wikipedia.org/wiki/Taxhttp://en.wiktionary.org/wiki/affordablehttp://en.wikipedia.org/wiki/House


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promoting economic and social integrationensuring that families housing costs are not sohigh that they cant afford to meet education and health costs and that there is sufficient

security of tenure to improve their capacity to obtain and maintain employment.

Residents:Residents of affordable housing benefit because it provides housing that:

is more affordable than that already available in the private market, thus still allowingadequate income for essential expenses such as food, clothing, health and education

integrates with the community provides a way for people to remain in areas in which they have lived for a long time, and to

live close to their support networks, during changes in life circumstances such as divorce,

retirement, or recovery from a long-term illness or injury.

Developers:Developers of affordable housing benefit because:

some local policies to promote affordable housing offer significant financial incentives fordevelopersfor example, through the provision of density bonuses

affordable housing provides housing close to employment centres, which supports a stronglabour force and a vibrant economy

there are often attractive returns to be made, especially from mixed developments or jointventures.

COST REDUCING FACTORS..

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.

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

Labour cost : 65 to 70 %

Image source : HousesHow to reduce building cost? By Lauri Baker.


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Areas from where cost can be reduced are:-1) Reduce 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 bricks.

3)Use energy efficiency materials which consumes less energy like concrete block in place of

burnt brick.

4) Use environmentally friendly materials which are substitute for conventional building

components like use R.C.C. Door and window frames in place of wooden frames.

5) Preplan every component of a house and rationalize the design procedure for reducing the

size of the component in the building.

6) By planning each and every component of a house the wastage of materials due to

demolition of the unplanned component of the house can be avoided.

7) Each component of the house shall be checked whether if its necessary, if it is notnecessary, then that component should not be used.

COST REDUCING FACTORS :

HOUSESHOW TO REDUCE BUILDING COSTS

Laurie Baker

INTRODUCTION:

Mr. Baker has been in this business of low-cost housing for nearly half a century and has

acquired immense experience of indigenous housebuilding techniques in various parts of

India and is at the same time well versed in modern techniques also.

Although born an Englishman, he came to India after taking his degree in architecture and for

some time worked with Gandhiji during the pre-independence days. It must have been during

those days that Mr. Baker developed his love of the poor and the passion to serve them.

The following pages attempt to show graphically the current and often expensive ways

of building.

IF you have to build your house on a terraced site, it is less expensive to place it in the middle

of the terrace.

Excavation : When exchanging the trenches for the house foundations, labourers digout the soil and throw it in all directions, especially outwards. After the basement

walls have been completed they then shovel all the soil back again as infilling. If they

shovel the soil inwards it will already be where it is wanted for infilling and some of

the expense of excavation and infilling will have been saved.


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Foundation : The extra and more costly foundation and basement wall that has to bebuilt if the building is near the edge of the terrace.

THE object or function of the foundation is to spread out the total weight of the house

over the ground below it. For small single and double storey houses an 18-inch (45-

cm) wide foundation base is usually fully adequate on most soils and there is not often

the need for the wider concrete layer beneath the basement wall. Where stone is

available, the ordinary simple 18-inch thick random rubble wall is perfectly adequate

to carry the full load of a single or double storey house unless the soil is very poor or

loose or of different consistencies.


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IN some districts stone and brick is not available. But some sort of foundation is needed to

carry a mud wall above.

The foundation trench can be excavated, the soil moistened with a little, water and then

replaced with layers of bamboo reinforcement inserted.

SOMETIMES stone is available, but only in small irregular shaped lumps. These make a very

poor wall that usually cracks and crumbles.Wood or metal moulds can be made of suitable sizes. (Say 12" x 8" x 6" or 12" x 6" x 4" etc.)

and these lumps are placed in the moulds and the spaces filled in with a weak lime or cement

concrete. This produces neat rectangular blocks with which walls of different thicknesses can

easily be constructed.


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Proper bonding : Masons are often more concerned with the outward appearance ofa stonewall than with its strength and stability. A plan of a stonewall as it is usually

built, with big flat-faced stones on the outside while the middle of the wall is filled inwith bits and pieces. BUT if stones should be bonded, that is they dovetail in with

stones on the other side of the wall and therefore give a much stronger and more

durable wall. A properly bonded stonewall hardly needs mortar, and certainly a mud

mortar is adequate, whereas the upper typical wall is not really safe without using a

cement or lime mortar.

A common practice is to have the main walls of a house in 9-inch thick burnt bricks, sitting

on the top of an 18-inch random rubble (roughly shaped stones) basement and foundation.

This means that there is a step where the 9-inch wall sits on the 18-inch wall below, andrainwater tends to seep in and weaken the lower stonewall.

For single and double storey houses it is better to put the outer side of 9" brick wall flush with

the outer side of the 18" stone wall so that rainwater running down the wall does not soak

into the wall.

This is also less costly because the stone 18-inch wall surrounding a room of a particular area

(say 200 sq. ft.) is larger (cubic content more).


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Walls : Bricks are often slightly irregular in length. So even if you can get a smoothfair face on one side of a wall, the other side will be lumpy and irregular. Therefore,

many builders say, you must plaster the wall. But plaster is costly (it accounts for up

to 10% of the total cost of a building). Also there is the painting and maintenance cost

of plaster too. The mortar can fill over the sunken ends of the brick to produce a

special fair face on the second side of the wall. Plaster is not required and a pleasingpattern has been made. No painting and no maintenance costs.

Brick bonds : IF burnt-brick is available, and if a 9-inch thick wall is required, 25%of the total number of bricks, andof the cost of the wall, can be saved by using aRAT-TRAP Bond. It is simple to build, looks well,has better insulation propertiesand is as strong as the ordinary solid 9-inch brick walls.

Flooring : Almost every sort of floor has to have solid base under it.Fill the basement with sand or soil at an early stage it will get trampled down solid as

work is done above it.

After the roof is on, collect all the broken brickbats side by side, touching each other,

on the rammed earth. Mix a small, heap of sand and lime on top of the bricks then

spread it out and brush it in so that it fills the cracks.


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Filler slab :TIMBER is becoming too scarce and costly.

As there is quite a lot of unnecessary concrete in an orthodox RCC slab we can replace some

of this redundant concrete with any light weight-cheap materials in order to reduce the overall

cost of the slab. This alternative RCC roof is called a FILLER SLAB. For fillers we can use

lightweight bricks, or Mangalore or country tiles etc. This will reduce the cost of theorthodox RCC slab by about 30 or 35%. As roofs and intermediate floors account for 20 to

25% of the total cost of a house, the saving by using a Filler slab is considerable.

Windows : Windows are costly. One square foot of-window can cost up to ten timesthe cost of the simple brick or stone wall it replaces. A window has varied functions -to look out of, to let light inside a room, to let in fresh air, or to let out stale air, and so

on. In many of these situations a JALI or honeycombed wall 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!


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When a window is a necessity it is quite a costly item.The simplest window consists of a

vertical plank set into two holes (or pivot hinges).

The traditional design consists of two short wood pieces with a circular hole in each,and the vertical shutter has two small round protrusions to fit into the-holes. Only

a nine-inch wide hole is necessary for the window.

This is strong, simple, inexpensive, very little labour, no iron mongery, lets in light and air

and provides security.

Lintels : Lintels are usually made of reinforced concrete. Steel and cement are used.Very often a lintel is not necessary over door and window openings up to four feet inwidth. Ordinary brick-on-edge, is all that is required.

If something stronger is necessary, a hollow arrangement of brick-on-edge,filled with

one or two steel rods in concrete will carry very large weights of wall and roof-etc.

above.This type of lintel is less than half the cost of the orthodox reinforced concrete

lintel.


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Doors : Door frames cost a lot of money and are often not actually necessary.Planks can be screwed together by strap iron hinges to form a door,

and this can be carried by hold-fasts built into the wall, thus eliminating the outer

door frame altogether.

THE door shutter itself is costly because it uses a lot of wood and quite a lot of costly labour.The simplest door is made of vertical planks held together with horizontal (sometimes

diagonal) battens.

Building orientation : IF the site is a sloping one, less excavation and less filling upis needed if you place the building parallel to the contours, and not cutting across the

contours.

SMALL flat-roofed boxes in long rows absorb a lot of heat from the sun. Pitched roofs

absorb less heat and of course still less heat is absorbed if fruit shade trees are grown on the

south and west side of houses, the houses are very much more comfortable to live in.

Transportation : Some-building materials are there for the using. Cut them, or digthem out and carry them to the site, and they are ready to use. Some such materials

need shaping and trimming. Others have to be processes or manufactured into more

complex materials. For example, some limestones can be used as building stones.

Burn them in a kiln and they turn into lime, which can be used with sand and water as

mortar or plaster, or it can be used as paint. By adding other ingredients and a lot of

manufacturing processes and a lot of energy (or fuel) we produce cement.

By using lime, which we can make, simply and with little energy and transport, on the

building site itself, we could save a lot of building money.


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Local material : At present cement and sand only are commonly used. This is easy tomix and use and it sets quickly. Similarly good strong mortars are made by adding

surkhi to lime and sand. Adding to the lime, or lime and surkhi mixes, a small amount

of cement can solve the slow setting problem.

Latrine : The DEEP PIT LATRINE, which is effective in all but very rocky sites.There is a pit about 3 feet in diameter and as deep as you can dig it.

A reinforced concrete filler slab with a latrine pan set into it (and a hole for a vent

pipe) is placed above the hole or Pit. If the soil is sandy or loose the top 2 or 3-feet of

the pit is lined with a 4.5-inch brick wall (or a well ring will do).

A screen wall and a vent pipe are built above the latrine slab.


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Natural material : A good nature bamboo can also be split in half and used as apermanent shuttering for reinforced cement concrete ribs between brick units (three

burnt bricks previously joined together with mortar to form a small slab). This is a

rural version of an orthodox reinforced brick slab (RBC).


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CASE STUDY:

B E L A P U R H O U S I N G /

A R T I S TS V I L L A G E, 1983-1986

LOCATION: BELAPUR, MUMBAI, MAHARASHTRA

BUILT BY: CIDCO

(CITY AND INDUSTRIAL CO-OPERATION OF MAHARASHTRA LTD.)

PLANNER AND ARCHITECT: CHARLES CORREA

BUILT FOR: LOW-INCOME GROUP

INTRODUCTION

Each house is freestanding and does not share any party walls with its neighbourswhich make it truly incremental, allowing its family to extend its home quite

independently, as and when the need arises.

Located on 6 hectares of land just 1km from the city center of new bombay, theproject demonstrates how high densities including open spaces; school etc. Can be

achived with the context of low-rise typology designed to accommodate 600 families

where individual plot areas vary from 45mt sq to 70 mt sq.

The houses built on incremental planning - they grow from single lean- to roof (forthe very poor) to the urban town- houses(for the well to do)

The site plan is structured by a hierarchy of community spaces.

Openings are permitted on any external wall that abuts the courtyard.


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SITE PLAN:

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The site plan shows that the orientation of the houses is around the common area. The planning is clustered. The stream is passing though middle of the site. Open spaces and common areas arefacing to the stream.
http://www.airoots.org/wp-content/uploads/2008/09/artistvillagesketch.jpghttp://www.airoots.org/wp-content/uploads/2008/09/artistvillagesketch.jpg


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PLANNING :

Project demonstrates how high density housing (500 people per hectare) can beachieved in a low-rise typology, while including open to sky spaces and services, likeschools, that the community requires

Overriding principleto give each unit its own site to allow for expansion(Incrementality)

Consequently, families do not share walls with their neighbors , allowing each toexpand his own house (Participation)

Houses constructed simply and can be built by traditional masons and craftsmengenerating employment for local workers (Income generation)

several plans exist that cover the social spectrum, from squatters to upper incomefamilies (Pluralism)

Yet, the footprint of each plan varies little in size (from 45 sqm to 70 sqm),maintaining equity (fairness) in the community

Scheme caters wide range from the lowest budgets of Rs 20000, Middle incomegroups Rs 30000-50000 and Upper income Rs 180000.

Though ratio of costs is 1:5 the variation of plot is much smaller , from 45 to 75square metres.

Seven units are grouped of 88 meters

3 cluster combine to form a larger module of 21 houses surrounding space of 1212metres.


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3 such modules interlock to define the next scale of community space approximately2020 metres

The houses are structurally simple , can be built and altered by local mistries Scheme caters wide range from the lowest budgets of Rs 20000, Middle income

groups Rs 30000-50000, Upper income Rs 180000

Though ratio of costs is 1:5 the variation of plot is much smaller , from 45 to 75square .


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source of image :http://krax.typepad.com/.a/6a00d8341c840353ef00e55510bf588834-800wi

BASIC CONCEPT :

Basic concept was that plot are to be allotted to the most needy persons at the pricethey can afford.

Services such as internal water supply, sewage, road, electricity and gas to beprovided as the allottee pay their monthly installments.
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The development of the scheme is incremental; the internal services are limited to thebasics, at the start only the communal water supply and public transport to the city

center are provided.

The incremental housing proposal allows a person to construct with five differentoptions in plots varying from 45sq.m to 70sq.m. according to their affordability.

The scheme with self financing without any element of subsidy from the government.

Speed and standard of development thus depend on installments, and the financial riskof the public agency is minimized as the work carried out on deposit basis and not on

recovery basis.

CONCLUSION:

The above list of suggestion for reducing construction cost is of general nature and itvaries 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 byutilizing the services of an experienced engineer or an architect for supervising the

work, thereby achieving overall cost effectiveness to the extent of 25% in actualpractice.

25 million families Without homes! Reduce building costs And build them now!

BIBLOGRAPHY :

Books :

HOUSES : How to reduce building cost ? By Laurie Baker. CHARLES COREA, by Kenneth franmpton, Topic name- Intremental housing at

belapur.

LAURI BAKERS Brick work, published by Cost ford centre of science &technology for rural development.

LAURI BAKERS Mud, published by Cost ford centre of science & technology forrural development.

http://en.wikipedia.org/wiki/Affordable_housing

http://www.housing.nsw.gov.au/Centre+For+Affordable+Housing/About+Affordable+Housi

ng/Who+Benef
http://en.wikipedia.org/wiki/Affordable_housinghttp://www.housing.nsw.gov.au/Centre+For+Affordable+Housing/About+Affordable+Housing/Who+Benefhttp://www.housing.nsw.gov.au/Centre+For+Affordable+Housing/About+Affordable+Housing/Who+Benefhttp://www.housing.nsw.gov.au/Centre+For+Affordable+Housing/About+Affordable+Housing/Who+Benefhttp://www.housing.nsw.gov.au/Centre+For+Affordable+Housing/About+Affordable+Housing/Who+Benefhttp://en.wikipedia.org/wiki/Affordable_housing


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COST REDUCING FACTORS

DESCRIPTION

A. SUB-

STRUCTURE 1.

EXCAVATION Shovel the soil inwards for infilling, so that it

will be already there where one wants &

thus the cost of excavation and filling will be

reduced.

2. FOUNDATION The foundation trench can be excavated,the soil moistened with a little, water and

then replaced with layers of bambooreinforcement inserted, so that cost will be

reduced.

3. BONDING Stone wall is usually built with big flat stones forexterior while the middle of the wall filled with

bricks &pieces instead of this if they dovetail in

with stone on otherside of the wall, it will give

much stronger,durable wall, thus reducing the

cost factor.

B. SUPER-

SRTUCTURE

1. WALLS RAT-TRAP bond can save upto 25%of the

total number of bricks & cost of the wall canbe save. Looks well, simple to build, good

insulation properties, strong.

CONSTRUCTION

OF WALLS

For single & double storey houses it is

better to put the outer side of 9 inch brick

wall flush with outer side of 18 inch stone

wall so that running down the wall doesnt

soak in to wall, thus reducing cost.

2. PLASTERING Usually, plaster cost upto 30% of total costof the building & again there is painting and

maintainance cost. Instead of this exposed

stone/brick wall can be constructed whichdoesnt need any painting & maintainance.

3. FLOORING Steps to reduce the cost of flooring- i)Fillthe basement with sand/soil at an early

stage. ii)After the roof is on place the

broken brick bonds side by side on ramp

earth. iii)Mix sand & lime on the top of brick

surface & spread it out.

4. WINDOWS Instead of window a jail or honey comb wallis more effective & if that of brick wall then

it can be very less costly & also if necessary

window can be replaced by the simple formconsisting of a vertical planks into two


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holes. Jalis are cheaper give permanent light

& ventilation.

5. LINTELS A hollow arrangement of brick on edgefilled with one or two still rodes in concrete

will carry very large weight of wall & roof.

This type of lintels is less than half the costof the R.C.C. lintel.

6. DOORS Cheaper doors can be formed by screwingup planks by strap iron hinges carried by

hold fast into the wall. Shutter can be made

up by vertical planks held together with

horizontal battens.

7. SLAB FILLER SLAB- Instead of R.C.C. slab we canuse light weight bricks, mangloore/country

tiles.

8. ROOF Instead of slab for houses pitched roof can

be used. This protects from heat & fungus,doesnt need plastering & maintainance.

C. OTHER

FACTORS

1. ORIENTATION OFBUILDING

If the site is sloping less excavation less

filling. Orient the building parallel to the

contour line. Pitch roofs absorbs less heat &

still less heat is absorb if fruit shade trees

are grown on the south & west side of the

house.

2. NATURAL

MATERIAL

Lime stones can be used as building stone

burn them & they turn into lime which canbe used with sand & water as for mortar &

plaster & even can be used as paint.

3. TRANSPORTATION Indians spends lots of money in importingcement from Corea. Cement can be

replaced by lime which we can made,

simply & with little energy & transport on

the building site itself.

electives report on low cost housing

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