I like the idea of the $300 house very much and yes I think it can be done.
I lived for 2 years (1979 till 1981) in India and I know the slums and the circumstances of the big cities very well. At that time I did a lot of building with bamboo and loam in Maharashtra.
A chinese saying is:� don�t give a fish to a hungry men, but learn him how to fish�. The same advice can be given in this project. Don�t give a poor men a readymade house, but learn him how to build and repair it with cheap materials and simple building technics. In this way a safe, sustainable and esthetic familyhouse of 14 M² + sleepingroom of 10 M² + toiletspace can be build for $300.
See Picture 1
The house I like to present to you is safe and sustainable in many ways. It is safe against:
- Fire: all the materials who can burn are covered with a chark ore loam layer and become fireproof.
- Water: not only the roof and the walls are waterproof against the monsoon rain, but also the first 30 cm of the visible foundation is waterproof against the monsoon flush (can be 20 till 25 cm high) on the ground.
- Wind and storm: through the bamboo skeleton construction and the aerodynamic domeform the power of the wind is no threat anymore.
- Rats,snakes and skopions: during the night the door can be closed and windows are covered with a iron mosquito-net for fresh air. The rats can not make openings through the walls ore the roof.
- Fungus and toilet-viruses: the roof and the walls take the humidity out of the room, so that there is no chance for fungus to grow . Every house has a privat compost toilet, so that toilet-virusses can not spread in the slums.
- Infections through drinking water: an 15 litre watercontainer with safe drinking water has to be part of every house. See further explanation on page 8.
- Darkness : every house has a system of 3 lights on sun-energy ($3 each) to avoid accidents in the dark. See further explanation on page 9
- Sexual-abuse: the sleeping space is on the first floor and the bambooladder can be taken up if danger is there. By putting on the lights the offender can be recognizes.
I like to explain the construction and materials of this house step by step, from the foundation to the roof with pictures and certain details.
The Foundation
See Picture 2
Be sure that the building ground is more or less on the same level everywhere by using a spirit level. Make two circles around a middlepole with a stick with 2 nails. The radius of the inner circle is 206 cm and the radius of the outer circle is 226 cm .
Dig a groove of 15 cm deep between the 2 circles. Also measure and dig the grooves for the toilet space and the entrance (see picture 2 � blue grooves).
Divide the groove in 12 parts with the help of a wooden triangle with two legs of 216 cm and a base of 111,8 cm. Put a polythene sheet (240 gram per M²) in the total circle and the groove .
Put the concrete supports in the divided parts of the groove on the polythene sheet and in the grooves of the entrance and the toilet- space.
Make sure that the concrete supports are exactly on the same level with a spirit level .
See Detail 1
The concrete supports are made in a 25 litre bucket with the following mixture:
- 1 part cement
- 1 part chalk hydraulic (to make them waterproof)
- 2,5 parts sand
- 1,5 parts gravel or small stones.
Put some oil or soap on the inside of the bucket, so that it becomes more easy to take the concrete block out of the bucket. After one day the block can be taken out of the bucket, but keep it wet for another 3 days to make the concrete real hard.
16 Concrete supports x 24 litre is 385 litre.
384 litre : 5*parts = 76,8 litre cement. 76,8 litre cement is about 96 Kg cement x 0,18 � = 17,28 � . * the cement and chalk are counted as 1 part.
76,8 litre chalk hydraulic is about 70 Kg chalk x 0,30 � = 21,- �
The sand and the gravel can be taken out of a river during lowwater and is free of costs.
PVC pipe 10cm - 16 parts of 15 cm =240 cm. 2.40 m x 2,16 � = 5,19 �
PVC pipe 8 cm - 16 parts of 30 cm = 480 cm. 4,80 m x 2,95 � = 14,16 �
PVC Glue , big tube 5,07 �
Costs of 16 concrete supports is 62,70 � (Shopprices in France)
See Picture 3
The next step for the foundation is to make the walls between the concrete supports with natural stones. The stones can be found in the fields, at the feet of the mountains or in the rivers during low water and are free of costs.
Materials to buy:
- 4 bags of cement of 35 Kg at 6,25 � each = 25,-�
- 4 bags of chalk hydraulic of 35 Kg at 10,50 � each = 42,-�
- Polythene sheet 240 gram per M² , 25 M² = 15 �
- Costs for the wall and the sheet is 82,- � (Shop prices in France)
The skeleton construction
See Picture 4
For the skeleton construction of the $300 house we use bamboo. Bamboo is the most fast growing tree on this planet and is as strong as steel. Different kinds of bamboos are growing in different continents. The Guadua Angustifolia is very populair in south America and is used for skeleton constructions.
In India the Dendrocalamus Giganteus is used for building and bridges. In the U.S.A. 50 seeds of the D.Giganteus costs $ 17,60. In India itself it maid cost just a few rupies. It takes some time for a bamboo seed to create a rootssystem in the earth, but if the rootssytem is there a D.Giganteus can grow up till 18 meters in 2 month time during the monsoon rain.
In the construction of the house the bamboos are connected with the concrete supports by putting the base of the bamboo over the PVC-pipe with a little space in between. (see detail on picture 4)
See Picture 5 and Detail 2
In the top the bamboos are connected to a big bamboo-pipe in an umbrella-form.
To give the rooftop more stability a second bamboo bow is also connected to the big bamboo-pipe. The bamboo-pipe is open to circulate condensed air, but covered with a little iron mosquito-net to keep the insects outside.
Other 12 bow-constructions are made to carry the beams of the first floor, where the family can sleep.
The price for the bamboo depends on the area. If there is a lot bamboowood around the city , than the price is cheaper . For one house the price for all the bamboo construction will be between $80 and $120.
The walls between the skeleton construction
For the walls between the skeleton construction I found 5 different solutions, who are cheap, easy to make, solid, fireproof, rainproof and natural. It depends on the area which solution is the best . I will explain all these 5 different wall constructions step by step.
See Picture 6
The most easy wall construction between the bamboo skeleton is Canosmose.
Canosmose is an old French building technic and is used again in alternative building. The mixture of Canosmose is:
- 1 part natural Chalk
- 2 parts fine Sand
- 2 parts Hempfibre
- enough water to make a pulpmass
The hemp fibre can be replaced by another strong plant fibre from that area.
The mixture is poured between two planks fixed on both side of the bamboo poles. In a few hours the mixture is solid enough to move the planks and to fill the next layer of canosmose. The technic is very easy and also a poor men can make a wall in this way. See houses of canosmose on : http://www.canosmose.com/
13 walls x 40 Kg chalk natural = 520 Kg. 520 Kg x 0,20 � per Kg = 104,- �
(Shop prices in France) The fine sand can be taken out of the river and is free.
The fibres ore twigs can be taken from strong plants and is free.
See Picture 7
Another cheap old french building technic for walls is called � Bois Maconnage�. A lot of summer houses in France are build in this way.
With this technic the wall is made of pieces of wood branches in about 20cm or 30cm lengths. In areas where there is a lot of woodcutting the branches are left over and can be collected for free. Pieces of 20cm are joined together with a mixture of:
- 1 part natural chalk
- 2 parts fine sand
- enough water to make a mortar for building.
13 walls x 25 Kg chalk natural = 325 Kg. 325Kg x 0,20 � per Kg = 65,.�
(Shop prices in France) The fine sand can be taken out of the river and is free.
The wood branches can be taken out of the forest and are free.
See Picture 8
A little more difficult technic is called � Käfigverputz�. It is an traditional german farmer technic to make solid walls. The first layer is made out of wire in a kind of cage-construction between the bammboo-poles.
The second layer is made out of tough twigs. In germany they take willow twigs.
The twigs are weaved through the cage-construction in a changing pattern, like on picture 8. The third layer comes on the inside of the house and is made out of a 1 loam- 2 fine sand mixture.
The fourth and last layer comes on the outside of the house and is made out of a 1 chalk � 2 fine sand mixture. The difficulty of this technic is the last layer. The mixture has not to be to solid and not to liquid. If it is to solid the pressure on the wall will be to strong and will break the loam layer on the inside. If it is to liquid the outside wall is not strong enough.
13 walls x 10 Kg chalk natural = 130 Kg. 130 Kg x 0,20 � per Kg = 26,- �
5 coils of wire 2,20 mm , 100 meter long x 8,25� each = 41,25 �
Total costs for the walls in this technic is 67,25 � (Shop prices in France)
The fine sand can be taken out of the river and is free.
The tough twigs can be cut from trees and are free.
The loam can be taken from the earth and is also free of costs.
See Picture 9 and Detail 3
In areas where the houses need to have a good insulation, because of the extreme heat or in cold periods, there are bales of straw or hey the best materiel to build the walls. Also in areas where there is a lot of grass or straw and less wood ore strong fibre of plants is building with bales a good solution.
Bales can be pressed by hand in a wooden box with a few old car-jacks very easy (see Detail 3). The grass or straw should be very dry. To make the bales fireproof, insect proof and ready for a loam layer on the inside they have to be dipped with the inner frontside in a loam soup for about 10 seconds. The soap-layer has to dry in the sun to become leather hard, before putting in the wall.
To make the bales fire, insect and waterproof and ready for a chalk-sand layer on the outside, they have to be dipped with the outer frontside in a chalksoup without sand for about 10 seconds. The chalk soup has to dry in the sun till it does not drip anymore, before putting in the wall.
On both sides of the bamboo frame there are 8 cm long screws sticking out.
The building starts with every new layer on the sides by pressing the bales into the screws to the bamboos. After that the bales in the middle are placed into the wall. After 3 layers of bales wooden stick are pressed from above through the layers to connect the bales and give the wall more stability.
The next step is to plaster a 3 cm loam-sand layer on the inside of the wall.
Then plaster a 3 cm chalk � sand layer on the outside of the wall.
13 walls x 10 Kg chalk natural = 130 Kg. 130 Kg x 0,20 � per Kg = 26,- �
(Shop prices in France) The fine sand can be taken out of the river and is free.
The sticks can be cut from trees and are free.
The loam can be taken from the earth and is also free of costs.
See Picture 10 and Detail 4
To bring more light into the house a few walls can be made out of empty glass-containers used for beans and other vegetables. A lot of light is important to scare the cockroaches and to keep the bedbugs away. The open side of two glass-containers of the same size can be put together with adhesive tape, to keep the inside free from dust, dirt and insects. The bottom of the glass-containers can be colored on the inside before with transparent color paint to make playful patterns in the glasswall.
The second step is to stack the glass-containers with a 1 chalk � 2 fine sand mixture with the round length side on each other. Finally only the bottoms of the glasses are visible on the inside and the outside of the house.
Costs for 3 glass walls is:
- 3 Walls x 25 Kg Chalk natural x 0,20 � = 15,- �
- 2 rol adhesive tape 2,-�
- 2 bottle paint-thinner 4,-�
- 4 tin color paint 0,5 litre 20,- �
- Total price 41,. � (Shop prices in France)
Door and windows
See Picture 11 and Detail 5
The front door is made from a frame of bamboo and hangs in a entrance frame, also of bamboo. The middle part of the door is made out of plastic watercontainers in 4 layers and is carried by a plank frame and horizontal lines of wire.
Costs:
- Bamboo-structure 12,- �
- Planck frame 2 x 2,40 m x 8,90 � = 17,80 �
- 3 metal hinges x 1,05 � = 3,15 �
- 30 m wire - 6mm 9,25 �
The roof construction
See Picture 12
A web of wire is stretched on the upper part of the bamboo-construction in a distance of 23 cm.
See Picture 13, picture 14 and Detail 6
The first layer on top of the wire-web consist of bundles of bamboo branches and leafs . Twigs from other trees are also possible. The bundles are buned together with a piece of string and are diped for a few seconds in a chalk yoghurt. Let it drip out and dry in the sun. The chalk layer makes the bundles fireproof and unattractive for insects. With the ends of the string the bundles are buned on the wire-web, starting on the lowest point of the web and than up.
The second layer comes on top of the bundles and is a mixture of 1part chalk and 3 parts hemp fibers, 5 till 8 cm thick. This mixrure is not only a solid base for the final layer , but is also a very good insulation against the heat of the tropical sun. The layer has to dry very slow to make it strong. A plastic sheet or other sun protection is needed for a few days.
The third layer consist of metal-plates out of tins. Tin food is used everywhere in the world and the empty tins can be collected for roof tiles. In Detail 6 it is showen how to cut the tin, bend the corners and drill the holes for the screws.
The tins can be given beautiful colors with metal paint, before put on the roof.
On the roof the tin plates are overlapping each other, so that the roof is everywhere closed for the monsoon-rain.
Costs:
100 m metal wire for the web = 8,25 �
3 role of string, 100 m each x 3,- � = 9,- �
2 box of screws 4,5 cm, 2 Kg screws each x 6,90 = 13,80 �
Metal paint 2 x 2,5 litre x 12,50 � = 25,. �
Total costs roof 56,05 � (Shop prices in France)
The compost toilet
No picture yet .
The compost toilet is made out of a big plastic container or 4 old car tyres connected together with bolts with a wooden plate on it. In the wooden plate is a hole with a cover on it. The compost toilet does not use any water, but just a little bit of sand after every use. In tree years the sudstance inside the toilet becomes good compost for the garden.
Costs:
16 bolts with nut, 8mm- 5 cm long x 0,10 � = 1,60 �
wood plate 60cm x 60 cm , 7,90 �
Total costs compost toilet : 9,50 � (Shop prices in France)
Drinking water
An 15 litre watercontainer with safe drinking water has to be part of every house. The watercontainer ist filled through a plastic funnel with a capacity of 5 litre. Down in the funnel a fine coffee filter in placed, where the water drips through into the watercontainer.
After 1 funnel of 5 litre 1 drip Natriumclorit* (NaCLO²) has to be put into the container to desinfect the water from germs and pathogen. * NaCLO² is allso known as MMS and is a very cheap but effective medicine again infection diseases and a lot more. See : http://purchasemiraclemineral.info/
Costs:
Watercontainer 15 litre : 9,95 �
Funnel big 5 litre : 6,85 �
Total water (without Natriumclorit) 16,80 �
Light from the sun
Every house has a system of 3 lights on sun-energy to avoid accidents in the dark. In France these kind of lamps are for the garden. They collect the energy from the sun and give light as soon as the sun sets for about 8 hours. It is easy to stick them in a bottle of sand and place them into the house whereever you need light. Cover the lamp with a black plastic bag to put it out, they don�t produce any heat. The next day you put them in the sun again to load them up.
Costs:
3 lights x 5,- � = 15,- � (Shop prices in France)
Total costs for this family house with all the extra things:
- Concrete supports 62,70 �
- Foundation 82,- �
- Bamboo construction 120,- �
- Strawbale walls 26,- �
- Door 42,20 �
- Roof 56,05 �
- Composttoilet 9,50 �
- Drinking water 16,80 �
- Lights 15,- �
Total 430,25 � = $ 608,20
The products in the 3rd world are much more cheaper than in Europe and U.S.A.
By grounding a building foundation, it is possible to buy the materiels directly by the wholesale trade (a shop makes 100 % profit on the products). By buying in big amounts there is always a discount on the products. So all together it maid be possible to build this family house for $ 300,-
