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