Browsing by Author "Khoshbakht M"

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    Do Green Buildings Have Superior Performance over Non-Certified Buildings? Occupants’ Perceptions of Strengths and Weaknesses in Office Buildings
    (MDPI AG, 25/08/2022) Khoshbakht M; Rasheed E; Baird G
    The main objectives of green buildings are to improve their design and operation. Many studies have investigated whether green buildings lead to higher occupant satisfaction, yet with contradictory conclusions. The paper builds on the results of post-occupancy evaluation surveys of 68 buildings using the BUS Methodology. Satisfaction scores expressed by occupants with the qualities of their indoor environment were compared between the green and non-certified buildings. This research investigates whether green buildings have superior performance to non-certified buildings from the occupants’ perspectives. It was found that generally occupants were more satisfied in green buildings than in non-certified buildings. However, the differences were not significant for any of the environmental and operational parameters including thermal comfort, lighting, noise, and air quality. In the case of operational parameters such as design, needs, image of the building, and cleaning, the differences between the two building groups were notable. Air quality, design and work requirement had the strongest influence on perceived comfort in both green and non-certified buildings. Noise had the strongest influence on perceived productivity for both building groups. Although overall green buildings performed better than the non-certified buildings, the differences between the two were negligible particularly for environmental parameters. Most of the green buildings were not performing entirely as their designers may have intended and had weaknesses that needed to be addressed.
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    Does the Number of Occupants in an Office Influence Individual Perceptions of Comfort and Productivity?-New Evidence from 5000 Office Workers
    (MDPI (Basel, Switzerland), 25/03/2019) Rasheed E; Khoshbakht M; Baird G
    Purpose—The purpose of this article is to present evidence of occupants’ perception of their work environment in five different office types (Solo, Duo, 2–4, 5–8 and 8Plus offices). The study examined the influence of the number of office occupants on individual perception of indoor environment quality (IEQ) in office environments. Design/methodology/approach—A dataset of 5000 respondents in 67 commercial and institutional office buildings was analysed using IBM SPSS v23. The dataset contained user response on the BUS Methodology questionnaire that is designed to retrieve occupants’ perception of their work environments. Analysis of Variance (ANOVA) and multiple regression analysis were conducted to calculate the impact of the office environment on occupants’ perception of comfort and productivity. Findings - This study showed that occupants in Solo and Duo offices perceived higher satisfaction with their environment (except for temperature in summer), better health and productivity; and more control over the office environment than those in 5–8 and 8Plus offices. Occupants in 8Plus offices were most satisfied with the temperature in summer. It was also noted that the IEQ factors that predicted comfort were observed to not predict productivity. Noise was the only IEQ factor that had predictive power for both comfort and productivity in all the office spaces. Originality/value—This article provides intriguing findings on occupants’ perception of various types of office environment that contributes significantly to the debate on open-plan versus cellular office environments.
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    Office Distractions and the Productivity of Building Users: The Effect of Workgroup Sizes and Demographic Characteristics
    (MDPI (Basel Switzerland), 2021-02-06) Khoshbakht M; Rasheed EO; Baird G; Arditi D
    Knowledge workers are experiencing ever-increasing distractions or unwanted interruptions at workplaces. We explored the effect of unwanted interruptions on an individual’s perceived productivity in various building types, user groups and workgroups. A case study of 68 buildings and their 5149 occupants using the Building Use Studies methodology was employed in this study. The database contains information on the occupants’ perceptions of physical and environmental parameters, including unmined data on the frequency of unwanted interruptions. Pearson’s correlation was used to test the correlation between the variables. In order to determine whether there are any statistically significant differences between the means of two or more independent (unrelated) groups, one-way ANOVA was employed to examine the significance of differences in mean scores between various user groups and workgroups. The evidence of clear correlations between the frequency of unwanted interruptions and perceived productivity is detailed in various user groups and in multiple building types. The Pearson correlation coefficients were−0.361 and−0.348 for sustainable and conventional buildings, respectively, demonstrating a lower sensitivity to unwanted interruptions in sustainable buildings. Females and older participants were more sensitive to unwanted interruptions and their productivity levels were reduced much more by unwanted interruptions. Comparing different sized workgroups, the highest sensitivity to unwanted interruptions for occupants in offices shared with more than 8 people was found. The findings of this study contribute to the understanding of different user needs and preferences in the design of workplaces