Occupant Health, Indoor, and Neighborhood Environment of Green versus Conventional Buildings: A Comparison Study

Abstract

Background: Under various green building certification systems, bonus credits can always be given to designs which allow higher degree of natural lighting and ventilation in common and background areas. This, to certain extent, makes indoor environment and occupant health in green buildings more susceptible to the influence of the neighborhood environment. This impact may be more significant on green building occupants, since green features, such as all‐glass curtain wall and low partition walls, are commonly adopted in green buildings to allow higher degree of lighting to penetrate into them. Objectives: This study aims to compare: i) health of green building occupants in low‐rise, low density versus high‐rise, high‐density neighborhood environment; and ii) the impacts of neighborhood environment on indoor environment and occupant health in green versus conventional buildings. Methods: To achieve these objectives, we studied 4 strategically selected academic buildings in Hong Kong, where two were green buildings, located in low‐density, low‐rise neighborhood environment and high‐density, high‐rise neighborhood environment respectively, and ii) the other two were conventional buildings, located in low‐density, low‐rise neighborhood environment and high‐density, high‐rise neighborhood environment respectively. Data was collected based on post‐occupancy evaluation of occupant health, indoor environment quality and neighborhood environment quality via questionnaire surveys. Purposive sampling was adopted, in which respondents were recruited only if they were academic or administrative staff working or students studying in the case buildings. In sum, 200 responses were collected, in which there were 50 responses from each of the building. Students accounted for 64.5% of the total sample, while academic and administrative staff accounted for 35.5%. Amongst the respondents, 56% spent 11‐30 hours in the building a week, 36.5% spent more than 30 hours and 7.5% spent 10 hours or less. Results: Based on the results of t‐test and hierarchical regression modelling, it was found that i) overall health of green building occupants located in low‐density, low‐rise neighborhood environment is significantly better than green building occupants located in high‐density, high‐rise neighborhood (P‐value < 0.01) [significantly lower frequency in dry eyes (P‐value < 0.05), watery eye (P‐value ≤ 0.01), blocked nose (P‐value < 0.01), runny nose (P‐value < 0.01), dry throat (P‐value < 0.05), irritated skin(P‐value < 0.01)]; and ii) neighborhood environment has more moderating effects on indoor environment‐health relationship amongst green building occupants [neighborhood building density and green area significantly moderate the impacts of indoor environment on runny nose, headache, water eyes, lethargy and blocked nose (ΔR2 ranges from 0.127‐0.225)] than that of conventional building occupants [neighborhood building density and green area significantly moderate the impacts of indoor environment on lethargy and sneezing only (ΔR2 ranges from 0.159‐0.286)]. Conclusions: The results of this study shed light to the importance of taking the influence of neighborhood environment into account when green building assessment is conducted, and this consideration should be applied across different development phases of a project, including planning, design, and post‐occupancy stages.