and their usage of the outdoor space.
This paper presents the first part of the field investigation, namely the materialization of greenery within the open space of three different individual housing typologies; detached, semi-attached and attached, detailing its spatial configurations( size, layout, proportion to the mineral space and location within the plot) and content( vegetation types and location) as well as assessed the impact on greenery of various plot sizes and building extension over time.
Objectives, Methodology and Context of Study
The detailed objectives addressed in this paper aim to:
• document and compare the size, proportion, form, location and the treatment of the vegetation within the open space of the house in the three common housing typologies i. e. detached, semi-detached and attached,
• record the type of plants, location and density of the existing vegetation,
• evaluate the impact over time of the built area’ s alterations( extension, addition, modification) on the original green spaces; and
• examine the impact of the plot size on the size of greenery. A qualitative exploratory approach was used to investigate the stated objectives through field observations in the form of architectural surveys of the current building footprint and greenery layout, while photographic surveys documented the type of vegetation and treatment of the open space. Prior to the field work, the original plans of the considered homes were retrieved from the archives of the municipal town planning department. These plans served to compare the current building with its original layout and evaluate the extent of alterations, if any, and their potential impact on green spaces.
The Es-Senia municipality was chosen as the study context for two reasons; first, because of the various typologies of individual dwellings it contains, second, it is the residence of one of the authors, which facilitated interactions with householders. Located at the southern outskirts of the main western city of Algeria, Oran, Es-Senia is particularly vital in urban research as it was among its first municipalities to experience the building of large individual residential areas since the French occupation( 1830-1962), a residential growth tendency maintained after the 1962 independence. The current study covered three housing developments built in the 80s and 90s. This period is considered sufficiently old enough to allow mature vegetation growth and building transformations to take place and subsequently allowing a good analysis of their impact on the green space over time.
Three main models of implementation on the plot based on existing urban housing typology, namely the detached, semi-attached and attached house, were considered. Each type generates a different open space configuration which in turn may affect the areas allocated to green spaces. The detached house sitting away from the plot’ s limits creates a square or rectangular open space ring around the house. The semi-attached unit, with one side attached to the adjacent unit presents a U-shaped open space, while the attached house adjoined on lateral sides allows two but separate open space areas( Fig. 1). The three developments considered in this study, consisted of the Marhaba Cooperative, with detached houses on a typical 400m2 plot sizes. The second, named CNEP Cooperative, has plots of 300m2 and contains semi-detached houses, while the third, located further to the east, named Amar-Bahi includes attached houses with plot sizes varying between 240 and 250m2. Each development consisted of the same respective plot sizes. These ranges of plot sizes are representative of most housing developments in the city of Oran as well as other Al-
The green space explored in different individual housing typology, Algeria 309