دراسة اداء الاضاءة الطبيعية للمباني السكنية متعددة الطوابق في قطاع غزة

Natural lighting in dwelling units is very important considering its effects on the visual comfort of occupants, and its role in energy saving. This design issue is more challenging in the crowded housing environments, where environmental and spatial design requirements have to be balanced. This is true in the case of Gaza Strip. Gaza Strip is a narrow strip stretching along the Mediterranean Sea. With its limited area and natural resources, urban areas are characterized with a high housing density. As a result, the quality of natural lighting in the residential buildings became questionable. This is because architects are under constant pressure from the developers and clients to design multi-unit residential buildings with maximum space utilization, in the face of rising land prices and scarcity. Thus, the challenge is to get daylight into rooms on lower floors that are overshadowed by adjacent structures. This depends on some internal factors such as size and position of the windows, the depth and shape of the rooms and the colours of the internal surface, and some external factors such as light reflected from the ground and opposite obstruction. Thus, this study aims to highlight the situation of daylighting in the multi-storey residential buildings at Gaza Strip, and to propose design recommendations to improve it. In order to achieve that, an parametrical study is carried out by "Radiance" program to assess the current situation in those buildings. The research concludes that a direct relationship between the illuminance levels that reaches inner spaces with window and well design. The study found significant effects of plan orientation, area, light well surfaces material reflectance, and opening area passes the light to the spaces on the illuminance level in the tested spaces. Light shelf has effective results on improving quality distribution of light Therefore, the research recommends applying natural lighting window and light well design strategies, Further studies are necessary which provide more data, and investigate more variables. Further work needs to be done to investigate the other daylight variables