Nonlinear relationships between individual IEQ factors and overall workspace satisfaction

Jungsoo Kim,Richard De Dear

doi:10.1016/j.buildenv.2011.09.022

Abstract

Despite a paucity of rigorous scientific evidence causally linking Indoor Environmental Quality (IEQ) issues to office occupants’ productivity, there is a widespread belief that such causality exists; excellent or poor IEQ translate into productivity gains or losses respectively. The aim of this study is to better understand relationship between perceived building performance on specific IEQ factors and occupants’ overall satisfaction with their workspace. Kano’s satisfaction model, developed originally in the context of marketing, is adapted and tested for its suitability in the context of building occupants’ satisfaction. Analyses were conducted on the occupant survey database from Center for the Built Environment (CBE) to estimate individual impacts of 15 IEQ factors on occupants’ overall satisfaction, depending on the building’s performance in relation to those IEQ factors. These empirical analyses identified nonlinearities between some IEQ factors and occupant satisfaction; some IEQ factors had a predominantly negative impact on occupants’ overall satisfaction when the building underperformed. These have been labelled Basic Factors in the Kano Model of satisfaction and include ‘temperature’, ‘noise level’, ‘amount of space’, ‘visual privacy’, ‘adjustability of furniture’, ‘colours & textures’ and ‘workspace cleanliness’. Other IEQ factors had a predominantly linear relationship with overall satisfaction – increments or decrements of equal magnitude in the building’s performance on these factors lead to a broadly similar magnitude of enhancement or diminution of occupants’ overall satisfaction. These were labelled Proportional Factors, and include ‘air quality’, ‘amount of light’, ‘visual comfort’, ‘sound privacy’, ‘ease of interaction’, ‘comfort of furnishing’, ‘building cleanliness’ and ‘building maintenance’.

Highlights

The topic of Indoor Environmental Quality (IEQ) seems to be generating increased research activity in response to growing awareness of the significance of IEQ issues to office-based workforces, and the linkage of sick building syndrome to poor IAQ (e.g. [1,2,3]) has served to heighten this awareness
Since this paper is focussed on the relationships between individual IEQ factors and overall satisfaction with occupant workspace, items on the Center for the Built Environment (CBE) questionnaire evaluating occupant satisfaction have been extracted for our analysis; 15 items focused on satisfaction with individual IEQ factors and one item for estimating overall satisfaction with workspace
By substituting these regression coefficients into Equation (1), an overall satisfaction rating score can be estimated from a given set of IEQ factor scores

Summary

Introduction

The topic of Indoor Environmental Quality (IEQ) seems to be generating increased research activity in response to growing awareness of the significance of IEQ issues to office-based workforces, and the linkage of sick building syndrome to poor IAQ (e.g. [1,2,3]) has served to heighten this awareness. The topic of Indoor Environmental Quality (IEQ) seems to be generating increased research activity in response to growing awareness of the significance of IEQ issues to office-based workforces, and the linkage of sick building syndrome to poor IAQ Occupants who are satisfied with the overall environmental quality of their workspace are widely assumed to be more productive [6,7]) It seems that occupants are being regarded like consumers of the product (building) and as such, entitled to be satisfied with the indoor environmental product. More research works dealing with building occupant satisfaction are being conducted than ever before. The adoption of occupant satisfaction surveys in the IEQ section of building sustainability rating schemes such as LEED (Leadership in Energy and Environmental Design) [8] and NABERS (National Australian Built Environment Rating System) [9] has sharpened the focus on how occupants perceive and use buildings

Objectives

Methods

Results

Discussion

Conclusion