ENVIRONMENT
A house shelters us from all types of climatic conditions, whether it be the heat, rain, cold, or humidity. It is therefore important to first carefully observe the local climate before designing or building a house.
There are three basic climates:
* The humid tropical climate with very warm temperatures which vary little between day and night, heavy precipitation and rich vegetation
* The dry tropical climate which is also hot, but has large temperature differences between day and night, little precipitation and therefore scarce vegetation
* The temperate climate with a very cold season and cold nights
Immigrants often build in their new homeland the same type of house they had before. This is a common mistake, and can make their houses inadequate for the local conditions, by either being very warm or too cold.
Before designing observe how the local people build their homes. This will help prevent importing designs and materials that do not suit local conditions. The house must adapt to the climate. -
HUMID TROPICAL CLIMATE
* Build houses close to hills or elevated sites where there is more air circulation.
* Build thin walls so humidity does not accumulate.
* Build sloped roofs to evacuate rainwater.
* use materials such as wood, bamboo and reeds.
* Install large windows to improve ventilation.
* Separate houses to allow cool breezes to circulate.
* Build verandas around the house to protect it from rain.
* Elevate the ground floor to avoid the earth's humidity.
DRY TROPICAL CLIMATE
* In regions with hills, build houses in the high areas where there is more air circulation.
* Use thick walls to decrease the penetration of the heat during the day and the cold at night.
* use materials such as stones, adobe, bricks and blocks.
* Install small windows to prevent the entry of dust and sun.
* Join houses to expose as few walls as possible to the sun. The houses then shade each other.
* Build interior courtyards to ventilate the rooms.
* Build the ground floor on the earth's surface to take advantage of the cool ground temperature.
TEMPERATE CLIMATE
* Build houses in areas with exposure to the sun.
* Build thick walls that prevent heat from escaping.
* Build roofs with an average pitch.
* Use materials such as wood, adobe, bricks and blocks.
* Install small windows on the south side and large ones on the north side. This applies to the Southern Hemisphere; do the opposite in the Northern Hemisphere.
* Protect the house from winds with vegetation and earth berms.
* Use the sunlight to heat rooms. Insulate the floor from the cold ground.
The environmental conditions where you build are not always clearly defined by the basic three climates. In some humid tropical regions forest resources have been destroyed causing a scarcity of wood for building. There are also dry tropical regions with green valleys and abundant palm groves, where the houses are built all in wood.
It is therefore recommended to build only houses that are most ecologically sound and in harmony with the local environment.
Today there are many opportunities to build with new types of materials or imported materials; however it is always preferable to use materials that blend in with traditional building types. Designing a house that is different from the local ones, by modifying all materials, the shape of house, the interior layout, and the use of spaces, eventually causes uncomfortable conditions.
A HOUSE AND ITS ELEMENTS
A house shelters in three ways:
1. protection from the sun and rain
2. protection from ground humidity
3. protection from wind
A house should withstand winds and the vibrations of heavY vehicles.
A house is composed of these three elements:
* walls
* floor
* roof
Problems such as water infiltration, insects, excessive heat or cold are first located in the joints or connections of these elements: roof, floor and walls.
After exposure to wind, rain or earthquakes, any construction defects often appear first in these joint areas.
USING THE ENVIRONMENT TO IMPROVE HOUSES
Environmental conditions are often misunderstood and not taken advantage of. By taking a closer look at the environment we can use it to improve housing and house systems.
It is not appropriate to imitate elements or construction styles from other regions with different environmental conditions. For example a window in a cold climate allows the sun to enter and warm up the room, but the same window in a dry tropical climate overheats the room and makes it unbearable to live in.
The roof, floor and walls should integrate into the natural environment and climate, and use it in a favorable way. There are detailed descriptions of ways to do this.
BUILDING ON SLOPED SITES
Often houses on sloped sites are built identically to ones on flat sites. The result IS an overspending on the construction of the foundation and the walls, and the destruction of the environment. When a s1te ts extremely sloped some earth should be moved but the plan should always suit the shape of the site.
A much more efficient house can be built on the same type of site by placing the spaces on several levels:
house sections
a) a flat roof
b) an inclined roof
- upper floor
- lower floor
c) a roof with 2 sloped planes
The money spent building retaining walls and infill can instead be used for improving other areas or parts of the house.
SUN AND WIND CONDITIONS
To prevent overheating the interior of the house, follow the principles below:
1. Prevent sun rays from hitting the walls
* with a large roof
* with eaves
* with trees
* with plants
* by protecting the longer walls from the sun
* by painting surfaces white
When the sun's rays hit an outside wall, they heat it up and eventually the heat penetrates into the interior spaces and the temperature inside the house rises.
2. prevent sun reflections from other surfaces:
If a house has many glass windows, the sun's rays can reflect off them and hit the neigh boring house on the other side of the street:
* large windows reflect sun rays
* water also reflects sun rays
Dark pavement or asphalt absorbs the heat and radiates it onto surrounding buildings.
* the dark ground absorbs and radiates
The best protection from this outside heat gain are plants and trees, which store cool air between their branches.
3. To well ventilate the interior spaces and keep the hot air circulating and non-stagnant, locate the doors and windows in relation to the prevailing winds.
* upper windows: the hot air flows
* tower windows: the cool breeze is felt
* wind entering under canopy
* percola or canopy separate from the wall
* the heat enters through the roof
* the heats exits the room
* air circulating from above to below is not very efficient
* air circulating from below to above is much more effective
* the closer hot air is to the head, the warmer you feel
* a cross-circulation is more effective with openings in the lower part of doors
* low trees: the breeze rises and does not enter
* high trees: the breeze descends and cools.
The distance between plants or trees and the house is also important, for example:
* when a hedge plant is 3 meters from a house, a breeze enters
* when a hedge plant is 6 meters from a house, a stronger breeze enters
A tree is more effective for cooling when it is planted close to a building:
* when a tree is 6 meters from a house, there is little breeze
* when a tree is 3 meters from a house, more cool air enters
Planting hedges around a house can also change the circulation of prevailing winds:
* without plants the breeze circulates around and away from a house.
* with a front hedge plant the breeze circulates further away from a house.
* with a back hedge plant the breeze enters and cools a house.
* With one back and one front hedge, a strong breeze enters.
ROOF VENTILATION OPENINGS
One way to prevent the house interior from heating up is to build openings in the upper part of the walls or in the roof. Since hot air always rises, these openings provide exits for the heat.
There are three ways to ventilate:
A. Allow interior hot air to exit:
* to let in cool outside air, the interior air must be evacuated.
Examples of method A:
- the hot air exits through openings in the upper walls
- the hot air exits through roof openings.
B. Prevent hot air from entering the rooms:
* the hot air flows into the eaves and exits through openings near the ridge.
Example of method B:
- another type of opening near the ridge
C. Draw hot air between the roof and the top of wall :
* with a flat roof the breeze lifts the air that is stagnant beneath the eaves.
Example of method C:
- the breeze enters through holed tiles in the upper part of the walls.
There are many types of site problems including odors, noise, smog, polluted water, unattractive zones, destroyed landscapes, and difficult infrastructure.
Industrial activities often are the cause of pollution in cities. These industrial activities can be less harmful if they are located in areas that do not affect the population. All factories should install equipment to treat their waste before it is disposed of.
* The factory waste will not affect as many people if the
river current is running away from the village.
Locate houses far away from the source of contamination.
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