Housing in Developing Countries – Areas of Concern
1. Severe shortage of houses in developing countries specially for
2. Severe problem of management of agro industrial waste in
3. Mounting pressure on non renewable energy resources. Non-
availability of energy efficient technologies for converting agro
industrial waste and renewable local resources into alternative
4. Expensive & scarce building materials and components
•Need for energy efficiency and environmental protection
in manufacturing technologies.
• Need to develop cost effective construction technologies
to mitigate the effects of natural hazards.
• Need to create employment and skill improvement
opportunities leading to poverty alleviation.
• Need to substitute expensive & scarce building materials
and components by low cost locally available materials to
suit local design typologies.
Housing in Developing Countries – Areas of Concern
Major Causes of High Building Costs
• Expensive materials
• Lack of necessary building skills
• Lack of guidelines in selection of appropriate
Low Cost or Cost Effective Housing
• Aims to reduce the cost of construction and at the
same time not sacrifice any element of safety or
serviceability of the house over the life cycle.
• environment friendly,
• ecologically appropriate,
• energy efficient
• affordable and adaptable
• cost-effective materials
• appropriate technologies in construction
Various aspects for cost reduction
• Optimisation of land use
• Functional design of buildings
• Optimum use of building materials
• Rationalisation of specifications
• New construction materials and techniques
Technology Selection Criteria
• Saving in cost, initial as well as recurring.
• Saving in consumption of imported or scare materials,
even if no saving in cost is achieved.
• Saving in time of construction.
• Utilization of waste materials even if no saving is
• Saving in quantum of skilled labour even if no
saving in cost is achieved.
• Achieving better utilization of equipment but not
necessary leading to optimum saving in cost.
• Better utilization of space.
• Better layout for economy in external services
Bamboo as a Material for
Housing and Buildings
– Indian Experience
Characteristics affecting usefulness of bamboo
as construction material
- the strength of bamboo culms
- their straightness
- lightness combined with hardeners
- range and size of hollowers
with good physical and mechanical properties,
low shrinkage and average density, it is well
suited to replace wood in several applications
Major Uses of Bamboo in Construction
• Doors & Windows
Bamboo – Nature’s Gift
[A material for cost effective and
disaster resistant housing]
As a Raw Material
1. High tensile strength
2. Very good weight to
3. Pressure tolerance upto
4. Easy to handle with
5. Renewable raw material
2. Energy efficient
3. Cost effective
1. Has short durability compared to wood
2. High moisture and starch content
3. Prone to fungi and beetle attach
4. Service life of untreated bamboo 4-6
years in exposed conditions
Treatment & Preservation
Preservation (Traditional methods):
Curing; Smoking; Soaking; Seasoning
Boric acid; Borax; Boron; (Dip diffusion or
modified Boucherie processes)
•BMBs, BMPB, BMCS
•Bamboo based shutters
•Bamboo flooring Bamboo House
Bamboo – Raw Material to Finished
Bamboo has lower natural durability against attack of
fungi and insects
- requires treatment to increase durability -
difficult to be treated by normal
preservative methods in dry
- Best carried out in green
IS9096:2006 : Code of Practice for preservation of
bamboo for structural purpose
Covers : Type of preservations,
Treatment procedure for structural purposes like post,
scaffolding, walls, trusses etc.
Process of Preservation
IS 401:2001 Code of Practice for Preservation of Timber
1. Surface application ( brushing, dipping)
2. Hot & Cold Method
3. Boucheire Process 5. Inter Nodal Injection
4. Diffusion Process
Structural Provision of Bamboo
Part 6 : Structural Design
Section 3: Timber and Bamboo: 3B. Bamboo
National Building Code.
- Physical and mechanical properties of
20 species of bamboo
- 16 species found suitable for structural
purpose and densified in Group A,B,C.
Pre-fab Double walled Composite House
Developed a technology for Pre-
fab Double Walled Composite
House with IPIRTI, Bangalore.
Material used are Bamboo Mat
Board for walling, BMCS for
Roofing with steel framed
Salient features are ease in
transportation, speedy erection
at a reasonable cost.
Most suitable for emergency
structures during post disaster
Two Storey Bamboo Housing System
Developed the technology with
IPIRTI, Bangalore using bamboo
Material used are Bamboo
coloums, Bamboo grid walls,
BMCS for Roofing, bamboo
composite beams with steel and
bamboo and bamboo composite
Development of this technology
will enable construction of two
storey houses in the bamboo
Bamboo Mat Ridge Cap for Roofing
Developed the technology with
IPIRTI, Bangalore for replacement
of the present practice of using
flat boards to avoid perforations.
Salient features are:
Ready & easy to fix
Suitable for wide range of roof
Compatible with BMCS.
Other projects completed in NE Region
Construction of 2 Cafeteria Buildings in Kisama,
Construction of 2 demonstration structures using
bamboo based technologies in Shillong, Meghalaya
Organisation of number of training programmes on
bamboo based technologies.
Preparation of detailed feasibility reports for
production ofbamboo based components like BMCS,
• Increasing durability
• Developing efficient
• Developing prefab
• Developing composite
system to deal with
• Growing bamboo of
• Setting up of more
• Studying other bamboo
which are available but
not used in construction
• Capacity building of
COST EFFECTIVE MASS HOUSING
MONOLITHIC CONCRETE HOUSING
What are the Requirements of an
Effective Housing System?
• Must be cost effective.
• Must be capable of a fast rate of construction.
• Must be adaptable to any structural design or
• Must produce high quality, durable and low
• Must produce structures that are resistant to
meteorological and/or seismic conditions.
MONOLITHIC CONCRETE HOUSING FORM WORK
• Hand-held reusable aluminum formwork system for
forming cast-in-place concrete housing.
• The System also controls the scheduling of the other
trades involved in the construction;
– steel reinforcement,
– mechanical and electrical,
MONOLITHIC CONCRETE HOUSING FORM WORK
• Can be used for any type of housing from; low
rise single or double storey housing, to walk-
up apartments, to high rise towers.
• Can be used for any income level of housing
from low income, to medium income, to
Features of the System
• Architect is not required to change the building
layout to suit the Mascon System.
• Capable of forming any type of structural design for
any type of housing.
– Column & Beam Design
– Loadbearing Wall Design
• The System is unique in that it forms all of the
concrete in a building including;
– floor slabs
– window hoods
– storage lofts
• No need for bricks, blocks or plastering.
• Multi-Storey Housing - structures are completed at
the rate of four days per floor - regardless of floor
• Single or Double Storey Housing - structures are
completed at the rate of one house per day.
• To increase the speed of construction, several “sets”
of formwork equipment can be provided.
• Precision in fabricating the Mascon formwork results
in accurate and consistent forming of the concrete.
• The quality of the concrete finish is the same
regardless of whether the System is used for low cost
housing or luxury housing.
Durability of Housing Units
• All concrete (walls, slabs, staircases etc.) are poured
monolithically, therefore, there are no construction
joints and no problems of leaking joints.
• The result is a rigid reinforced “box” structure that is
structurally very durable and very resistant to
meteorological and seismic conditions.
Why is this System
So Cost Effective?
• Highly reusable formwork.
• Forms all the concrete in a building.
• Unique construction cycling.
• Uses locally available materials - i.e. concrete and
• Requires unskilled labour only and no cranes.
• Loadbearing wall structural design.
Innovative Building Technologies:
Machine that produces HI-CSEB, developed by
Auroville Earth Institute, Tamil Nadu, India
Aurum Press 3000
friendly, easily available, stronger, energy
saving and simple to
Better Thermal Insulation
Warm in winter and cool in summer
Technical /Engineering Aspects
Soil Identification – Top soil and soil with organic matter should not be used.
Grain size distribution - more of sandy is preferred.
Gravel (mm) Sand(mm) Silt(mm) Clay(mm)
20 to 2mm 2 – 0.02 0.02 – 0.002 0.002 - 0
Some basic test for identifying the suitability of soil
•15%gravel, 50%sand, 15% silt, 20%clay
(Grain size distribution test)
•Compress a moist soil by hand
•Difficult to compress – gravely soil
•Very easy to compress – Clayey soil
(Ease of the soil to be
•Smells Rotten – lot of humus
•Musty – humus
•Agreeable smell – no humus - suitable for construction
(presence of organic materials0
•Difficult to break – clayey soil
•Breaks easily – gravely soil
Plasticity ( Capacity to withstand
•Wash the hand on which the soil paste was made
•Soils grains does not stick on the palm – Gravely soil
•Thin film of soil stick on the palm – clayey soil.
Cohesion(Property of the soil
grains to remain together)
• Cement : Soil (1 : 6)
• Water content = 25 liters for one bag of
• Varying the ratio esp. the cement has the
proportionate cost involved
• The ratio can go up to 1 cement to 10 soil
Same basic data on CSEB
Dry Compressive Strength @28days
3 – 6Mpa (N/sqmm) ( +10% after 1 year,
20% after 2years)
Wet compressive strength @28days (3days
2 – 3 Mpa
Dry bending Strength @28days 0.5 – 1 Mps
Dry Shear Strength @28days 0.4 – 0.6Mpa
Density 1700 to 2000kg/cum
Water absorption @ 28days after 3 days
immersion 8 to 12 % by weight
Energy Consumption 110MJ ( Kiln fired bricks = 539MJ)
Comparison with other building blocks
Properties CSEB (HI - 245) Ordinary class III
Size 245x 245 x 95 195 x 95 x 75 390 x 190 x 190
Weight 8kg 3kg 16kg
30 – 60kg/cmsq 35kg/cmsq 45kg/cmsq(approx)
Cost (Nu.) 13 per block ( 1:6
11 per brick @
38.00 per block @
For a 250mm thick 1msq wall in a load bearing building @ Thimphu
Block Numbers Cost(Nu)
HI - CSEB 40(Approx) 520
Ordinary second class brick 166(approx) 1496.00
Hollow concrete Block 19.5(approx) 741
Block production machines
Two Machines in the market
1) HI – CSEB Block machine – Habitech centre, Thailand
2) AURUM PRESS 3000 – Auroville,India
Designer/ manufacturer Auroville Earth institute/ Aureka,
Cost of Press Rs 69,800.00
Cost of Mould ( 1 set) Rs 41,500.00
Max Blocks size 245 x 245 x 95
Compression force 150KN( 15 tones)
Production capacity per
day with 7 workers
500 Blocks (average)
Designer/ manufacturer Habitat centre , Bangkok
Cost of Press 73,500.00 (Nu) 2008 rate
Cost of Mould ( 1 set) -
Max Blocks size 300 x 150 x 95
Production capacity per day
( 6- 7 workers)
Pilot House Construction – SQCA using HI – CSEB 245
• Two storied load bearing structures - serve as model
for the earthquake resistant design features
• Sample Blocks test results
Soil sample source Average Compressive Strength
Proposed construction site (1:8 mix
ratio 22 kg/cmsq
Buddha Dodema site ( 1: 8) 33 kg/cmsq
1. Use of cheap & locally available materials
2. Job opportunity for local people
3. Biodegradable materials
4. Energy efficiency and eco friendliness 5 – 15 times less energy consumed
than fired brick and around 3 – 8 times less emission
5. Transferable technology
6. Import Reduction
7. 7. Cost effectiveness
8. 8. Minimum mortar required
9. 9. Keys that interlock with each other provides better integrity
10. 10. Hollow provisions for laying vertical and horizontal reinforcements to
improve the lateral load resisting capacity
11. 11. Ease and Fastness in construction
12. 12. Fire resistant
• Only for low rise structures: maximum 2 storey
• Strength very much dependant on the properties of
• Too much stabilization(cement) will make no economic
• Interlocking features do not provide air tightness.
Minimum gap is formed due to which termite/air
current can pass.
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