Technologies for Rural Development/Building houses

Building houses

The building of houses is fundamental for human development, especially in areas of the globe with extreme weather conditions.

It is very important for family and for general social development, because it is where we live and so it must be comfortable and healthy. Many types of houses are difficult to build; they require a lot of knowledge and work to create them.

To be a good house it must comply with a few basic functions.


 * Be a functional and health environment for those that live in it.
 * Inside of the house one must be protected from wind, cold, heat, rain sand and dust.
 * Last few many years without requiring much maintenance.

There are many ways to build a house. Houses vary according to their location; they change due to cultural differences and also due to the local resources available to create them. In cold places houses must be more compact and have thick walls and small windows to resist the cold, they also have heating systems. In the hottest places the houses are built below ground level so that the earth keeps them cool during the day, they also have central courtyards to create shade from the sun. The forest areas the houses are made from wood, en the mountains they are made from stone, in areas with clay they are made from brick. In areas where there is seismic activity it is important to consider this when designing the structure of the house. Each country has its own regulation to guide this work.

Housing for Cold Climates
In cold climates a house must insulate its inhabitants from the outside temperature. This is achieved by creating walls that are made from materials that insulate well, often requiring layers of different materials. It is also necessary to include a heating system for the house. The type of heating will depend on the resources available (wood, gas, kerosene or electric), this should always be minimised by using the passive solar heating that the sun supplies. To make the passive solar heating from the sun more effective it is important to orientate the most important rooms towards the equator. (In the Southern Hemisphere towards the North, and in the Northern Hemisphere towards the South).

Passive Heating of Houses
Passive heating of living spaces is created by what is called the “greenhouse effect” because a greenhouse is a building made of glass used to grow plants in cool climates or accelerate growth by increasing the warmth.

Glass creates a greenhouse effect because the glass only transmits some light waves, this means that the light is trapped inside and bounces around within the area; the result is that there is more heat gain through the window, than heat loss.

Resources for good insulation:

 * Thick walls and ceiling made of materials with low heat transfer.
 * Walls and ceiling filled with insulation material that creates an air space (glass wool, cork, hay etc.)
 * Walls and ceiling with an air space (a double wall or ceiling).
 * Walls and ceiling insulated from water so that heat is not transferred with the moisture.
 * Doors and windows that insulate (double glazed or double doors). And that way the heat from the heating will stay in the building

Housing for Hot Climate
In hot areas it is important to cool the house down to make it comfortable to live in. The house must have walls and ceiling that insulate the inter spaces from the outside heat just like a house in cold climates.

The house must also have as much of its walls and floor in contact with the earth because the earth does not heat up as much as the air especially if the night time temperatures are lower than the day time temperatures.

The house must be shaded from direct sunlight this can be done by building the house partially under the ground, or by planting trees around the house.Cavity wall construction can be taken up at south and west sides considering the solar path.

Housing for Windy Climates
Houses built for windy climates need to be strongly anchored to the ground and need the roofs to be designed to support the force of the wind.

Choosing the right materials
Choosing the right materials to build a house depends on the region that the house it to be built in. Each area of the planet it different and has many different materials that can be used for housing.

Earth Bricks
Earth bricks can be made from some types of clay it is a very common material and requires very little energy to turn into a construction material.

Required Resources

 * Spade or shovel
 * Cement
 * A press to create the earth bricks

Construction System
The earth is mixed with a small amount of cement (without water) and then pressed into brick shape and left to harden. The humidity of the environment will enter the brick mixing with the cement and harden it. Normally small bricks are made so that they are easy to transport and work with.

It is considered one the most environmentally friendly construction methods.

The main disadvantage is it can not be used in the construction of the roof unless a arched or domed roof is created.

Ceramic Brick
This brick is made from clay which when heated goes hard to form a brick. It is very common in many parts of the world, but it is a material that is very fertile and so its use for construction reduces the fertile land in the area, it also used a lot of heat energy for its creation.

Wood
Wood houses has a long tradition in Asia, and the United Status. If there are renewable wood forest to supply the wood very efficient construction can be done by creating kit-set houses.

Necessary resources

 * Pieces of wood cut to size and dried.
 * Saws, hammers and nails also bolts for more important joints..

Construction system
The wood must be cut into lengths; these are normally standardized so that builders can use the same practices for more than one house. These are used to create the structure of the house and panelling is used to close the house. Insulation should be included between the inner and outer panels. Wood does not resist water and will rot if not treated with chemicals in humid climates. Because of this it is best suited to dry climates.

Installations
A good house should also have running water and a toilet and bathroom so that the inhabitants can keep clean and also have access to water to drink and cook with.

Environmental considerations
Tecnologías para el Desarrollo Rural/Cómo Construir una Casa

Links
http://en.wikipedia.org/wiki/Passive_house