Factors contributing to the construction of Homes in Senegal
Documentation
- Auberge
This location shows how the environment is taken into consideration where wind and natural light is used from the outside. This is a relaxing area where no extra energy such as light or air conditioning is usually needed due to the use of the space.
The way this location in the Auberge uses the courtyard is a really great way where it takes into consideration all the natural light provided by the sun and has shade through the use of vegetation.
This is an example of the type of windows currently used where the slant in the windows allows for natural light and wind circulation to occur. This type of design however does not allow for them to be closed and let mosquitos and other bugs in.
This is showing another view of the upstairs lounge area in the hotel where the space is clearly meant to resemble the same purpose as courtyards do, a place to socialize and relax during the day.
2. Sacree Coeur
This is an example of a recent neighborhood development in Sacree Coeur where middle class homes are being developed and are taken environmental aspects into consideration. This includes better air circulation through the different designs for the windows, doors, and outside elevations. The second story shows a incorporated porch design which helps with ventilation.
This picture shows one of the temporary homes being built all around Dakar so that land can claimed. These homes provide many jobs but are not efficient material-wise as these homes get destroyed after they are approved and are usually replaced with the homes in the previous page.
3. Thiaroye Sur Mer
Location: Thiaroye Sur Mer.
It is one of the poorest neighborhoods of Dakar. The houses are built right next to each other and a small alley separates block of houses. The doors and windows have small openings to let the air in.
4. Keur Momar Sarr
This shows an upclose view of a window style where air circulation is being taken into consideration and is a cheap and affordable alternative to a window with glass.
This temperature reading was taken from one of the bedrooms in Keur Momar Sarr and shows how hot it can get and the current temperature at that moment. It reached a peak of 84 degrees Fahrenheit and was currently that temperature when this picture was taken in the afternoon around 3 pm.
This is showing the temperature inside of a school room in Keur Momar Sarr where as can be seen, can get really hot but with low humidity.
Analysis
- Doors
As can be observed through the pictures above, some people would rather have air circulation than safety from mosquitos and malaria as temperatures can get really high, especially within a confined space. Doors would best be made from wood since it has a lower heat coefficient than most materials used for doors. Metal doors have a heat coefficient of 1.2 Btu/hr ft^2 degrees Fahrenheit while wood can either be .45 or .65 Btu/hr ft^2 degrees Fahrenheit.
- Roof
The roof is a very important aspect within the construction of homes and buildings and does not seem to be as high in priority. Roofs can have a major impact on the temperature within a home. A high solar reflectance is the most important characteristic of a cool roof as it helps to reflect sunlight and heat away from a building, reducing roof temperatures. A high thermal emittance also plays a role, particularly in climates, like in Senegal, that are warm and sunny. Reduced energy use makes a cool roof transfers less heat to the building below, so the building stays cooler and uses less energy for air conditioning. Roofs can also Improve human health and comfort as cool roofs can help to prevent heat-related illnesses and deaths. Together, these properties help roofs to absorb less heat where this can have an impact on the lifestyle of its inhabitants.
Chimney (stairs)
Although chimneys are not too common, chimneys can affect air circulation quite well in favor of the homeowner. Roofs create the stack effect which will cause air circulation. During the hot season, the warmer indoor air rises up through the building and escapes at the top either through open windows and ventilation openings. Since warm air is rising, it reduces the pressure in the base of the building where cooler air can come in through windows. One way that can create this stack effect is through staircases as was the case where we spent our nights in Keur Momar Sarr. This style allows for air circulation without interfering much with the homeowner’s lifestyle.
image from: 
- Sun directions
After several interviews with masons and homeowners, the findings about the sun direction was the same, it was not taken into consideration in the design and construction of buildings. However, knowing the direction of the sun is critical while building a house, especially when it comes to the openings and ventilation. Knowing the positions of the sun at each time of the day enables the architect to design accordingly. For example, facades on a house to provide shades for the building and help with overheating.
- Wind Directions
Another important aspect to consider when designing a building is the wind directions, especially in countries that are affected by high wind currents. Surprisingly, there were little to none consideration to wind directions in building designs and constructions in the places visited in Senegal. Even though people knew the wind direction, this critical information was ignored.
In the school in Keur Momar Sarr where we visited, the buildings were built against the wind directions. Therefore, the rooms temperature were very high and the air did not circulate easily.
By knowing the wind direction, architects can provide openings to ease the ventilation inside the buildings. In a classroom in Louga, the windows were built to facilitate the ventilation inside, making the room very comfortable.
- Property of Materials
For roofs, one of the most commonly used materials is corrugated metal. Corrugated metal is available in sheets with wavy ridges and is used in construction projects for roofing or siding. It is lightweight and economical to install and is highly durable and is able to support a large amount of weight without buckling. Homes in coastal regions are more likely to use corrugated metal, since it is a moisture-resistant material. It is a low-maintenance choice, and may be less expensive to install than other building materials, such as brick or concrete. This product can also be recycled, and this fact makes it attractive to homeowners who want to go "green." Corrugated metal siding can be made from aluminum or steel. Aluminum is the material of choice in areas near the ocean, since the aluminum will react with the moist, salty air to form aluminum oxide.
When looking at heat transfer coefficients, corrugated metal as a roofing material is 1.5 Btu/hr ft^2 degrees Fahrenheit while 2 inches of concrete slab has a coefficient of 0.3 Btu/hr ft^2 degrees Fahrenheit. As can be seen, concrete would be preferable as it has a lower heat coefficient.
Tile roofing, which lasts a long time and will not burn under a scorching summer sun, is a great choice for warm climates. Clay tile, which was used in one of the schoolhouses, usually last longer than any other kind of roofing material. Tiles are also fireproof and resist rot and insects. These tiles are however very heavy that the roof needs reinforcement to support its weight. Concrete tiles will last just about forever but the the material they lie on will go bad every eight to twenty years. Tile roofing is also expensive which explains why it is not used as often.
- Challenges with Ventilation
Even though ventilation is an important aspect to consider in building construction, there are some challenges associated with ventilation, especially in the country of senegal.
- Insects and Diseases
By letting too much air in, there is a risk of letting insects inside the house, especially mosquitoes. Most houses are build with a central open courtyard. The courtyard helps with the ventilation, however, it allows mosquitoes to get in and spread malaria. In the raining season, malaria cases may increase due the the high number of mosquitoes. In the dry season, there are a lot of flies that spread diseases such as typhoid fever, cholera and dysentery.
- Energy costs
The lack of proper ventilation causes many Senegalese families to invest in fans or air conditioners, which drive their electricity cost very high. In an interview with Aminata, a jewelry seller on the Island of Goree, she revealed that she spent about 20,000 F CFA, an equivalent of $40 on electricity each month. Her energy bills represent a big portion of her volatile income. The reason why her energy cost is so high is the fact that her one room house does not have the proper ventilation to provide a comfortable and cool environment.
- Dust
Because of the dry and arid climate, dust is a threat to many households. Therefore, without proper ventilation techniques, the wind can spread large amount of dust inside buildings, making inhabitants lives very difficult. In the recent years, the numbers of dust storms has increased because of climate change.
image from http://newscenter.berkeley.edu/2011/12/12/climate-change-kills-trees-in-africa/
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