A quantitative study for indoor workplace biophilic design to improve health and productivity performance

It is well known that greenery biophilic design can improve health and productivity, but studies are still needed to quantify greenery dose and corresponding well-being benefits to support design practice. In this study, we investigated impacts of various greenery dose on workplace well-being from the perspectives of physiological, psychological, and productivity performance. A repeated measures experiment was conducted, in which green coverage ratios, 0, 0.2%, 5%, 12% and 20% were tested, and both health and productivity performance of 15 participants were measured by advanced devices, questionnaire, and tasks. Eye tracking tests were also recruited to verify that health and productivity benefits were caused by visual contact with greenery that attracted participants’ visual attention. Regarding productivity, we observed improving working performance at all the cases with greenery. But green coverage ratio 0.2% and 5% are not enough to create restorative effects to change psychological response and 20% ratio is too overwhelming. Meanwhile, only green coverage ratios 12% and 20% could cause the positive change on physiological brain activities. Therefore, we identified 12% green coverage ratio as the optimal greenery dose for the office after integrating the results on psychological, physiological, and productivity performance. This research outputs provide not only the important measurement datasets for quantitative biophilic design research, but also important understandings to support biophilic design practice since green coverage ratio is one of the most important design parameters.