The proposal is for a multi storey building which comprises of offices and lofts and is located in the centre of Jordan’s capital. The design process begun with the, study of Amman’s urban environment, it’s organizational principles and the study of the typology of the structures located in the neighboring area This analysis and the study of Jordanian architecture, informed the volumetric investigation which started with a plain parallelepiped, parallel to the building plot’s shape and attached to the adjoining buildings.
Consecutively, the lower edges are drawn towards the street grid, while the volume is detached from the inner boundaries of the site. The elaboration on the volume’s skin, as the final border with the city and the one that determinately conveys meanings and symbolisms to the contemporary city, is what will form the connection with the specific location. For this reason, various patterns observed in traditional Jordanian architecture were studied, along with the various methods of their scheme reproduction.
There is a Muslim belief that one can find geometry in the design of all life forms from animal and plant cells, plant forms, snow, and geological structures hence the expression “geometry is God manifest”. Islamic religious architectural design is based on ‘sacred’ geometry, consisting of, or generated from, such simple forms as the circle and the square. These geometric patterns were combined, duplicated, interlaced, and arranged in intricate combinations. There is an Islamic belief that studying the nature of these patterns, forms, relationships and their connections, insight may be gained into the mysteries - the laws and lore of the Universe.
The pattern that was finally selected to be processed was eventually projected onto the primary volume’s faces, expressing the forces that act upon it. The primitive box, the one that will accommodate the building’s functions, is enclosed in this ‘veil, which also defines the extent of the city’s flow into the building, allowing a gradual interplay between indoors and outdoors, differing from floor to floor, in accordance to the needs of the equivalent level. The inner border, the back planes neighboring with the adjacent building plots, is covered with a layer of low planting, responding to the green border encountered between the neighboring building blocks. It is in this way that this relieving green breath creates a special environment for the building, forming the background of the architectural synthesis and cumulates towards its intended clearly recognizable identity.
The main vertical and horizontal circulation to the upper floors (offices, apartments) is situated in the space created by the detachment of the building from its site’s boundaries. In this way the circulation is accomplished outside the main core of the building and allows the visitor to entry the enclosure only through small openings, gradually revealing the interior spaces.
The layering of the spaces follows the required sequence and reflects the gradual accession of the social privacy. The stores, as the most public part of the program, are situated on the ground and the first floor. The connection between the two floors is established through a single route beginning from the main entrance and resulting at the second floor, symbolizing the incoming of the city into the building. The organization of the commercial units mimics the structure of the traditional bazaar. We consider the bazaar as a paradigm structure of the merchandising local practice, which comprises a vibrant hub for social interaction. The core element of the bazaar, the spinal of its structure, the main route that fuels the stores, is interpreted here with this very path, with the commercial units being organized around it. As far as the offices are concerned, the main goal during the design was to achieve maximum organizational flexibility for the user. Considering a single desk as the primary unit, and a library stack as the secondary element that acts as a dividing boundary between two desks, various geometries were studied, resulting to various combinations of the congregation of the units. The benefit of this organizational method is that each working team will be free to customize the working space according to its number of members and their requirements. The top level of the building is purely residential in use and houses two spacious family lofts.
Bioclimatic strategy
Topography- Climate
Amman is located in a hilly area of north-western Jordan. The city was founded on seven hills, but it now spreads over an area of nineteen hills. Because of the cooling effects of its location on a plateau, Amman enjoys four seasons of temperate weather as compared to other places in the region. Summer temperatures range from 28 °C -35 °C, but with very low humidity and frequent breezes. Spring and fall temperatures are extremely pleasant and mild. The winter sees night time temperatures frequently near 0 °C, and snow usually falls a few times each year. The yearly average number of days with rain is 5-45 and with snow it is 0-8. It typically will not rain from June to the beginning of September, with cloudless blue skies prevailing.
Environmental control
Solar avoidance. The goal is to keep direct solar gain out of the building. During the daylight hours completely avoid letting direct sun enter the building.
Avoid daytime ventilation. The daytime air in hot climates is dry and very hot. It is not wise to encourage it to enter the building.
Promote nighttime flushing with cool evening air. The evening air in a desert climate is substantially cooler than in the daytime. The promotion of ventilation in the cool evening hours will draw heat out of the thermal mass of the building and cool it down.
Achieve day lighting by reflectance and use of light non-heat absorbing colours. By the use of light colors the building will not attract or hold as much solar heat as dark colors absorb heat. Light colors will also help light to bounce around and achieve a good level of brightness without the use of direct beam radiation from the sun.
Implementation
The solar avoidance is achieved by the orientation of the building and the use of the building skin as a shading device. The buildings front façade is facing south east. Solar penetration occurs only for few hours after dawn. The early morning solar radiation is not that intense as mid day. The solar rays that enter the building from northeast facade are diffused by the fenestration equipped with electro chromatic glass. The buildings white concrete skin deflects and diffuses the direct solar radiation. It is the depth of the building skin that allows it to act both as a shading device and a light self. This means that it blocks the direct sun rays and at the same time it diffuses and redirects them to the interior. The diatoms of the skin and its thickness were designed in accordance with the solar path in order to achieve the desired lighting and shading conditions. The rest of the exterior surfaces like the caps of some diatoms of the diaphragm wall are also light colored to avoid the overheating via solar radiation .The interior finishes are light colored too to promote the light enhance to the interior.
The ventilation during the day is achieved by the use of earth tubes, long, underground metal or plastic pipes through which air is drawn. As air travels through the pipe it gives up some of its heat to the soil, and enters the building as cooler air. This happens because the natural ventilation in hot arid climates during the day would equalize the interior exterior aerial mass temperature. This would lead to thermal discomfort and unnecessary rise to the building mass temperature.
Natural passive ventilation occurs only during the evening hours. The reason is that evening air temperature is much lower and the breezes can be taken advantage of to cool the building mass. The larger amount of open able fenestration is located at the two larger facades to provide for cross ventilation. Cooling via cross ventilation happens at night time via the system of remote controlled operated fenestration and openings. The air enters the building at a low entry point and is exhausted at a higher exit point. The moving air cools the building and prevents condensation. Incorporated openings in the window frames allow small amounts of ventilation in spaces intended to be naturally ventilated when open able elements are otherwise closed. These openings are called trickle ventilators and are remote controlled via a central computer. The trickle ventilation is equipped with special ‘wet’ filters to keep sand and debris outside the building envelope and also to humidify the air supplied to the interior.
In Jordan, high temperatures, humidity and dusty hot winds lead to excessive discomfort for people. In order to relieve the residents from the harshness of the climatic elements we decided to create a microclimatic zone. A microclimate is a weather pattern that’s localized in a small area and different in some significant way from the weather of nearby areas. The variation can be one of temperature, humidity, rainfall, wind, or any combination of these. An improved microclimate in the vicinity of the building can improve the quality of life and comfort for its users. The changes we want to implement regard relative humidity, air temperature, wind flow and light exposure. To achieve that, we created a gap between the building and the site boundary. At the edge of the boundary a vertical structure was erected in order to facilitate a vertical garden and its embedded watering system. The plants on the wall not only absorb carbon dioxide and exhale oxygen but play and active role in the regulation of the microclimatic factors as they alter the temperature, the relative humidity, filter the air and diffuse the air flow. The gap between the building and the green wall lets the air drafts move within it and drive away the saturated air volume keeping the cooling rates at a high level and maintain the comfortable conditions for the residents.
The active heating of the building is conducted by under floor heating system fed by geothermal heat pump (GHP) and a supplement boiler. GHP acts as a central heating or cooling system that pumps heat to or from the ground. It uses the earth as a heat source (in the winter) or a heat sink (in the summer). This design takes advantage of the moderate, stable temperatures in the ground to enhance efficiency and reduce the operational costs of heating and cooling systems. The top 3.0 m of Earth's surface maintain a relatively constant temperature between 10 and 16°C. The geothermal pump systems reach fairly high efficiencies (300%-600%) on the coldest of winter nights, compared to 175%-250% for air-source heat pumps on cool days. Ground source heat pumps (GSHPs) are among the most energy efficient technologies for providing HVAC and water heating. For the building in Amman a vertical system was selected mainly because of the limited space provided and the increased demand. Holes (approximately 10 cm in diameter) are drilled about 6 meters apart and 20 meters deep. Into these holes fit two pipes that are connected at the bottom with a U-bend to form a loop. The vertical loops are connected with horizontal pipe (i.e., manifold), placed in trenches, and connected to the heat pump in the building.
The active cooling of the building is conducted by GHP and active solar cooling system. Geothermal heat pumps act as a cooling system in the summer pumping cooler water from underground to cool the building. Active solar cooling system is used as a cooling strategy to relieve the building from unwanted heat load and maintain conditions of thermal comfort in the interior. Active solar cooling technologies use solar thermal energy provided through solar collectors to power thermally driven cooling machines. A solar cooling installation consists of a typical solar thermal system made up of solar collectors, storage tank, control unit, pipes and pumps and a thermally driven cooling machine. A conventional energy source functions as auxiliary, mainly for the periods when the cooling load is not covered by the produced energy. The machinery is located in the plant room in the underground level. The solar collectors are integrated on the buildings roof.
Passive cooling
In the summer, sprays can be used to achieve optimum natural cooling. The water is pumped to sprinklers along the top of the building and allowed to trickle down the sloping facade. The rate of evaporation is greatly enhanced in such a system because a much larger surface area is exposed to the night air. Roof sprays rely on a little external power to get the water to the roof and hence do not qualify as completely passive systems. But the total amount of energy consumed for pumping is very minimal compared to the energy saved by the added cooling rate attained. Excess water can be captured and reused. The same technique is used for the watering of the green wall opposite the south façade. The gap between the building and the green wall lets the air drafts move freely and drive away the saturated air volume keeping the cooling rates at a high level and maintain the comfortable conditions for the residents.
Gray water recycling.
The building is equipped with gray water collection and purification system. Gray water is considered the wastewater generated from washing of clothes and dishes and bathing which can be recycled on-site for uses such as irrigation. Grey-water composes 50–80% of residential wastewater generated from all of the building sanitation equipment (except toilets).The grey-water system, it is essential to be fed nothing containing toxic substances—no bleaches, artificial dyes, cleansers in order to avoid soil and irrigation contamination.
Conclusion
Designing in a hot and arid climatic zone can be very challenging especially when strict environmental and energy criteria are taken into consideration in the design process. The aim here was not only to create a functional comfortable building but also an icon for the city in terms of visual appearance, cultural connotations and environmental performance.
