Effect of Bioclimatic Features on the Performance of Daylight in Selected Private Hostel Buildings in Obafemi Awolowo University Ile-Ife, Nigeria

The study examined the effect of bioclimatic factors on the performance of daylight in selected private students’ hostel buildings in Obafemi Awolowo University Ile-Ife, Nigeria. The study assessed the daylight performance of hostel buildings; examined occupant satisfaction with daylight performance; assess the effect bioclimatic features on the performance of daylight with a view to reducing dependency on artificial lighting in hostel buildings. Quantitative data were obtained through objective measurement for both indoor and outdoor illuminance of the selected hostels using light meter. Qualitative measurement was used to examine the occupants satisfaction with daylight in students’ hostel, field observation was used to assess the effect of bioclimatic designs on the hostels daylight. Data was analyzed using description, code, percentage and content analysis. The results of field measurement shows that the indoor illuminance ranged between 0.17lux and 986lux, while the calculated daylight factor ranged between 0.0008 and 2.05%, which implies that the illuminance level of the selected hostels is considerably poor when compared with CIBSE lighting guide 10 which recommended that the minimum illuminance for study room should be between 300-500lux, only AP hostel met the standard daylight performance (1.62 and 2.05). The result also shows that buildings oriented towards the east and west directions have better indoor illuminance (11.24 to 986lux) and better daylight factor (0.022 to 2.05) compared with north and south direction. The result of qualitative measurement shows that 62% of the respondents agrees that natural lighting is adequate while 38% of the respondents opined that natural lighting is not adequate. The result of bioclimatic designs shows that building forms, layout, orientation, courtyards, light shelves, screen wall, green environment, corridors and shading devices were major bioclimatic design features initiated in the hostel buildings, but only BVRE, AP and Rock of Ages hostels demonstrated a better daylight due to the integration of courtyards, light shelves and green environment. The study concluded that the illuminance level is not adequate but however, recommended that future designs of private hostel buildings should integrate bioclimatic design features such as building layout, courtyard, light shelves and green areas and to also educate design practitioners on the need to integrate daylight parameter in hostel designs.