Plans And Designs Of Earth Sheltered Homes - Research Paper Example

Plans And Designs Of Earth Sheltered Homes The purpose of this paper is to focus on a particular technology by considering its various structures, characteristics, benefits and disadvantages. For the purpose of the study, this paper focuses on partially buried buildings or more appropriately, the earth shelters. At first, the paper gives a brief introduction of the process of earth sheltering. Then it moves onto discuss the unique characteristics and distinctive features of the technology that has been used in the houses. This section examines the performance and physical characteristics of the houses and tries to establish the facts responsible for the creation of such houses. Then the paper focuses on the benefits of the building of the houses as earth shelters. Also, it is very important to discuss the flaws of the technology, in terms of the usual problems faced by the residents of such houses. The paper also sheds light on the theory and concepts that are responsible for the construction of earth shelter homes. The latter part of the essay deals with the application of some of the characteristics of the earth sheltering technology to other more modern architectural designs Introduction For most of the people today, as Hamid and Din (1991) relate, earth sheltering is a novel idea. However, this is not the actual scenario. Earth shelters have existed since the prehistoric times. They have been prevalent everywhere, from the cave men to the houses belonging to the ancient Southwest Anansazi Indians. More recent additions to the kind of earth shelter houses were built in 1193 in Iceland. Figure 1 shows some of the houses that are still present in Keldur, Iceland. In conditions of extreme heat and violent conditions, men have always sought the protection of the earth, as Hamid and Din (1991) discuss. For example, in AD 800, the people originally belonging to Cappadocia, in order to protect themselves from invaders and remove the scarcity of timber, built the underground chambers amid rocks. The same trend of earth sheltering can also be experienced in other parts of the world. The paper will now discuss the concept of earth sheltering and the characteristics of the technology used in the process of earth sheltering. Figure 1 Earth Sheltering And Its Characteristics Earth sheltering, according to Roy (2006), is a phenomenon whereby the architectural practice of a house or a particular building is carried out using earth. The process generally makes use of earth against the building walls in order to reduce heat and to maintain a stable indoor temperature. Earth sheltered houses are built in three different manners, namely earth beaming, In-hill construction and underground recessed construction. In earth beaming, the earth is piled down and packed away from the walls. The roof may be earth sheltered too but it is not really a necessity. Also, the windows might be present on either side or both sides of the house in the earth beaming process. On the other hand, in hill construction requires a house to be built on a slope or a hill. This means that such houses have only one exposed wall, or the wall that is outside of the hill or slope. The underground recessed construction, unlike the in hill construction and the earth beaming, requires the ground to be completely excavated. Also, the house is set below the ground level. Often in such houses, there exists a particular space that is left out in between so as to leave some area for light and vegetation. Figure 2, showing the Hotel Sididriss in Tunisia, is an example. Figure 2 The Physical Characteristics of Earth Sheltering The people who are not really aware of the basic concepts of earth sheltering usually assume that the insulation of the earth is mostly responsible for the thermal excellence and energy savings that are generally a characteristic of the underground houses. Though, this is not the real scenario. It is true that enormous amounts of earth that covers two or more sides of the house, including roofs, may actually have an insulating effect. But, according to Hamid and Din (1991), the amount of insulation provided by a rigid material would require many meters of earth. So it means that a few meters of earth provide negligible insulation. Roy (2006) also states that the insulation property of the earth is merely a misconception. The reality is that the earth is not a very good insulator, with its best insulating properties to be found in the first few inches of the soil. As one moves deeper into the earth, the insulating property actually diminishes. In Roy’s (2006) words, the earth is very poor in insulation. As a consequence, the real energy saving potential of the earth sheltered homes is because of the physical characteristics present in the homes. Soil temperature and heat loss It is a fact that houses that are earth sheltered generally lose less heat through walls and roofs as compared to the conventional architectural structures that lose a lot of heat in winters and absorb greater amounts of heat in summers (see Figure 3). The earth that surrounds the walls and the roofs of the earth sheltered homes work as temperature moderators. This means that the earth tries to reduce the loss of heat in winters and the gain of heat in summers. Since the temperature of the soil is relatively stable, in summer, the interior portion of the house loses heat to the soil instead of gaining the heat from the surrounding air. In the same manner, the soil in winter gains heat from the surrounding relatively warmer temperature. Figure 3 The concept of the reduction of the heat in summers and the increase of the warmth in winters can be easily and clearly confirmed the examination of the daily and yearly soil temperatures. The daily fluctuations that take place in the weather, especially the temperature, conditions are eliminated at a depth of 20 cm only, according to Boyer and Grondzik (1987). At even greater depths, the only fluctuations caused in the soil temperatures are seasonal and this change usually occurs with a lot of delay. An example is that of the Minneapolis-St. Paul area in the US. The temperature recordings of the area from time to time offer a trend in the seasonal soil temperature fluctuations along with the fluctuations in the surrounding air temperatures. Although the temperature of the surrounding air or the air in general for that matter, fluctuates as much as 68°C (122”F.), from -30°C (-22°F.) to 38°C (100°F.) annually, there is no change that occurs in the soil that is 5 to 8 m in depth. There however exists an annual soil temperature range of 22°C (75°F) three meters below the surface of the earth. This verifies the theory of Boyer and Gronzdik (1987). According to Hamid and Din (1991), ‘the slowness with which soil temperatures change creates a thermal flywheel effect that contributes significantly to the energy efficiency of earth sheltered dwellings’. An example again is that of Minnesota where the soil that in just 3 meters below the surface of the earth experiences its coldest temperature in early spring on contrary to experiencing it in the most cold months of the year. Similarly, the soil gets the warmest usually in the month of November, a month that marks the start of the cold winter. This means that the soil gets warmer when winter arrives and gets colder when the summer season is starting. As a consequence, no resources are utilized in the providing of comfort to the residents of the houses. For instance, there usually is no need for air conditions and heaters. Hence, the time periods of the year when different fossil fuels are required the most, are cut short due to the delay in the registering of temperature fluctuations in the soil. So the earth sheltered houses generally work as energy savers. A further explanation of the concept is also given by Figure 4. The concept of thermal conductivity takes a new meaning when it comes to the explanation of the transfer of heat in the soil. (Earth sheltering) When there is a transfer of the heat from the wall of the house to the ground, the ground gets heated. This is because the ground is not free to move and so cannot get away or dispose off the heat through convection. As a consequence, the first layer of the earth gets heated up quickly. However, the second layer of the earth’s surface may take twice the amount of time required to heat up the first one. The reason for this phenomenon is that as the depth increases, more and more mass of earth is readily available to absorb the heat. There is a time delay in the heating process because the greater the mass of the earth involved, the greater the time that is required to cause a change in the temperature of the soil. The same trend is true for all other increasing depths. As one move further deep into the ground, the effects of the mass on the heat flow and transfer are amplified and there arise greater fluctuations in the surface and subsurface temperatures. This phenomenon, as mentioned above, causes the earth sheltered houses to have a stable interior temperature, thereby causing them to be more comfortable in all seasons and as an indirect consequence, saving energy. Figure 4 Another energy saving characteristic of the earth sheltered homes is the fact that the houses are less infiltrated. Infiltration usually results in heat loss in normal or conventional houses. Usually a conventional house is not really well built. The consequence is that it loses most of its energy to the surroundings by cracks in windows, doors and throughout the entire architectural structure. The process of the loss of heat gets more stringent when the wind blows. The wind takes away any heat that is ‘accumulated’ in a house thereby causing problems, especially in winters. This is not the case in the earth sheltered houses. If properly built, the soil is able to protect the house from either the cold or the hot air. As a result, the infiltration in the house is greatly reduced. This in turn reduces the air conditioning and heating bills. Due to the thermal mass of the earth sheltered building, the heat storage capacity of the building is greatly enhanced. This is a very important characteristic of the earth sheltered buildings. The thermal mass of an object or a particular structure is dependent on both the density and the quantity of building materials. The thermal mass is also a function of the ability of the building materials to store heat. Earth sheltered houses are very important in this regard because they are generally made of concrete, in order to withstand the pressure exerted by the ground on the walls. In theory, every building that has a large thermal mass absorbs a lot of heat in the day either through the air or through the radiation of the sun and releases the heat energy back into space at night when there is lesser flow of heat. This means that a building with a greater thermal mass helps the transfer of heat from a higher temperature atmosphere to a lower one. Earth sheltered houses and buildings are no exception. In an earth sheltered house, the process of the heat transfer is quite slow and it may take a large number of hours to ‘carry’ the house without actually requiring heat from a source outside like the sun. On the contrary, conventional houses and buildings are unable to store excess amounts of heat and they may lose the entire heat energy that they have gained in case the source of the heat is interrupted. This means that the heat that may be gained due to the radiation of the sun or through the surrounding air in the day may be absorbed but not retained by the conventional dwellings. The result is that they lose so much heat that it is difficult not to use heaters in winters, especially at night. Now that the characteristics of the earth sheltered houses have been discussed in much detail, it is important to focus on the technology that is used in the housing types. The House types According to Ahrens et al. (1981), earth shelter houses are not necessarily built in proper designs. However the two most important design concepts that are discussed in the paper are the elevational and the atrium plans. The single exposure elevational designs are particularly used in climates that are generally colder. In such an architectural structure, the windows and the doors are grouped together on a single exposed elevation. This elevation usually faces the south in the colder climates and the north when the climate is relatively hotter. Since all the openings are on one side, the other remaining three sides are left buried in the ground. This kind of structure is beneficial in the colder climates because the energy requirements of the structure, that already are low because of the limited exposure to the weather outside, are further reduced by creating the windows facing south. South faced windows generally maximize the benefits of solar heating. This may be important but the three most important determinants are still the sun, the wind and the outside views. A proper orientation of the house can help it achieve greater energy savings. The sun is one of the most important sources of energy when it comes to the construction of energy saving buildings. According to Keehn (1987), radiant energy from the sun can be used in both active and passive manner in order to provide heat to a particular structure. The houses that make use of the active solar energy are usually the ones that face the south. As far as the passive heating methods are concerned, the energy is generally collected through the trapping of the heat that has been transferred to the interior of the house through the windows. Wells (2009) believes that the passive solar collection is critical to the saving of energy. This is because it does not include any capital expense that may otherwise be associated with the active solar collection. Also, the passive solar collection provides a great deal of energy as compared to the active solar collectors. If the effect of the sunlight is considered only, the best manner in which an earth sheltered house, especially in cold climates, may be orientated would be to place all the windows on the southern side and cover all the other three sides of the house with earth. This is because; the passive solar collection of energy is usually not possible when the windows face the west, the east and the north side. The noteworthy fact here is that although sunlight and the radiation from the sun may be beneficial providers of energy for the earth sheltered houses in the colder climates, they do not work the same for houses that are locates in the hot climates. This situation usually gives rise to the consideration of the effect of the wind. The effect of the wind, along with the radiation from the sun, is crucial for the orientation of the earth sheltered houses. In cold climates, a direct exposure to the wind reduces the heat transfer and at the same time increases the heat lost. Therefore, houses in cold climates require the buildings to be as protected from the wind as possible, according to Woods (1985). Most of the winds of the northern hemisphere are from the North West in winters. Therefore, the earth sheltered houses in the northern hemisphere tend to reduce their energy losses by minimizing the number of openings and windows that face the west and the north. The summer breezes in the northern hemisphere, on the contrary, are from the south east but they depend on various other factors too. In most of the southern hemisphere, the winter winds originate from the south east direction while the summer breezes come from the north west, completely opposite to the northern hemisphere. Earth sheltered construction thus can help the residents develop a structure that can in turn help protect the inner temperature of the houses by providing protection from the harsh winter winds. However, at the same time, it is also important to create a system of cross ventilation in the house. This is usually done by creating some outlets for air on the opposite sides of the front wall of the building, as Hamid and Din (1991) relate. In the courtyard or the atrium designed (see Figure 2), the rooms are built in a manner that helps them to group around a central courtyard. This courtyard provides ample amounts of vegetation because of the easy access to the natural light. In colder climates, this kind of structure can be covered with glass so as to provide protection from the winder winds. The open courtyard, though, is more suitable to the hotter climates. This is because the surrounding air can be used for the cross ventilation so as to remove the excess heat that may be caused die to excessive solar radiation. An advantage of such a technology is also the privacy that is provided. The grouping of the living space around an atrium helps to develop flexibility. This is because the structure can be groups in any manner possible unlike the elevational plans whereby the structure necessarily has to have a southerly exposure. Now that the technology used and the considerations taken during the process of the building of earth sheltered houses has been discussed in much detail, it is important to move on to discuss the fundamental concept on which the earth sheltering technology is based. The concept of earth sheltered houses According to Boyer and Grondzik (1987), the concept of earth sheltered houses focus on the respect for the environment and the elements that exist within the atmosphere. This means that the basic idea of the creation of the houses and buildings has been the preservation of the earth and the elements belonging to earth itself. It seems that the concept for which the houses had been created initially is achieved to a greater extent. As mentioned in a lot of detail before, the earth is used as the building material in the earth sheltered buildings. The use of earth means that no other artificial building materials have to be used to ensure that a house is built properly. The building of conventional houses and buildings require a lot of resources, most of which can be used for other purposes. For instance, according to Golland and Blake (2004), huge amounts of timber forests have been cut down in order to provide for the construction needs of the increasing human population. Timber and certain other types of trees have been dwindling in numbers lately because they are most widely used in the construction business. Forests are natural habitats for many animals, birds and insects. The cutting down of the timber forests mean that all these living things are getting extinct because of a lack of a place to live; that is a different story altogether. However, the main point is that the use of construction materials in the buildings is disturbing the ecosystem by reducing the number of trees. From here we can in a way conclude that the earth sheltered houses are in reality a physical manifestation of the concept of the preservation of resources. This is because the earth sheltered houses require no particular construction materials. Wood may be used to decorate the interior of the house but it is not really essentially required for the process of construction. The same is true for other construction materials like the cement. The construction of buildings underground also means that there is reduced heat flow. The concept of soil moisture and temperature and the impacts on the houses have been emphasized greatly in the prior section of the essay. The automatic cooling in summers and the heating process in winters is an incentive because no fossil fuels are used to restore heat. Since air conditions are rarely used in the summers, less damage is caused to the ozone layer as a result of the emission of lesser chlorofluorocarbons (CFCs). Similarly, since heating is not required in the winters, heaters are seldom used. The consequence is that non renewable resources like the coal are not exhausted in the process of providing heat. Hence the earth sheltered houses do not just save its elements like the trees and the non renewable resources, but also ensure that lesser pollution is caused to the atmosphere thereby leading to a greener environment. The impacts of the understanding of earth sheltering on modern architecture By now, the concept of earth sheltering has been greatly understood. Now it is important to discuss how the technology used in the earth sheltered houses can be modified and applied on a larger scale. The main purpose for which earth sheltering was started was to preserve the earth and the environment. Many studies show that this objective has been largely achieved. Earth sheltering has not just helped restore the eco system but has also helped revive the atmosphere with an emphasis on energy saving. Sadly, most of the architectural designs today do not consider the concept of energy saving. Very few architects realise the potential of energy saving mechanisms and many are least bothered about the shortage of resources that may arise due to their unnecessary usage. The fossil fuels that exist in the world today are dwindling rapidly and according to a study, by 2050, the coal and oil reserves of the world would be completely exhausted. It is time that the architects realise that energy saving is one of the most important issues of the world today. If the architects create designs that are more energy efficient, there would not just be a reduction in the usage of resources, but also an increase in the usage of the resources in more constructive things. It is quite disturbing that most of the forests and fossil fuels are used for the construction industry. If instead, the earth sheltered technology is used, it would help sustain energy. It is true that the initial cost of the creation of earth sheltered houses is very high but the low maintenance cost covers for the effect of the initial higher cost. Also, no heaters and coolers are required to create a stable inner temperature. Architects should therefore encourage buildings that may serve for the energy losses that are prevalent presently. Conclusion To conclude, earth sheltering is a phenomenon whereby the ground or the earth is used against the walls in order to create buildings. Earth sheltered houses are unique because they provide the comfort of a stable temperature throughout the year. Since the soil does not heat up or cool down very rapidly, the inner temperature of the house remains almost constant. The earth sheltering houses are built on the principle of the saving of energy. Also they help protect the earth and its elements. By giving a little consideration to the effect of the sun’s radiation and the winds, the houses are built in a manner that helps reduce heat loss in winters and helps increase the heat loss in summers. The whole mechanism is based on the saving of energy. That is why no air conditions and heaters are required in houses that are underground. Earth sheltered housing is essential in today’s world where the natural resources and fossil fuels are depleted on a day to day basis. Since a large chunk of the fossil fuels is used in the construction industry, it is important that architects recognize the worth of the earth sheltered houses. The architects, like all other responsible artisans, need to help encourage people to adopt manners of living where the wastage of energy should be greatly reduced. The introduction of earth sheltered houses would be a good start for the conservation of energy, a solution that needs to be adopted by the entire world. References Ahrens, D. Ellison, T. and Sterling, R. (1981). Earth sheltered homes: plans and designs. US. Van Nostrand Reinhold Co. Blake, R. and Golland, A. (2004). Housing Development: Theory, Process and Practice. UK. Routledge. Boyer, L. and Grondzik, W. (1987). Earth Shelter Technology. US. Tamu Press. Hamid, A. and Din, M. (1991). Earth Sheltered Housing: An Approach to Energy Conservation in Hot Arid Areas. Saudi Arabia. King Saud University. Keehn, P. (1987). Earth-sheltered houses: an annotated bibliography, 1950-1985. US. McFarland. Roy, R. (2006).Earth-Sheltered Houses: How to Build an Affordable Underground Home. US. New Society Publishers. Site Editor. (2010). Earth Sheltering. [Internet] Available from(Accessed 4 September 2010) Wells, M. (2009).The Earth-Sheltered House: An Architect's Sketchbook. UK. Chelsea Green Publishing. Woods, C. (1985). The complete earth-sheltered house: passive solar, low maintenance, low cost, modular design. US. . Van Nostrand Reinhold Co. Read More