A Real-world Study of the Relationship between Subjective Assessment of Productivity, Subjective Perception of Environmental Conditions and Objective Productivity Measures

Improvements in staff productivity have been identified as a leading driver for commercial companies in the design of healthier and efficient buildings. However, evidencing improvements in productivity is difficult owing to the considerable number of environmental variables and behavioural differences between people. Consequentially, there are few real-world case studies evidencing how, why and if the environment has an impact on productivity. Current methodologies are based on objective measurements such as absenteeism/presenteeism, staff turnover and medical/physical complaints but, these data can be difficult to gather, are not collected to a set methodology and require significant resources to organise. An alternative and simpler method has been to ask staff how they perceive their own productivity which is used in many Post Occupant Evaluations (POE) included in the Building Use Studies (BUS) Methodology and the Leesman Index Survey. Whether this corresponds with actual productivity levels and environmental preferences is often questioned in real-world scenarios. This new study demonstrates this relationship through an evaluation of two office spaces. Occupants were given subjective questionnaires, objective cognitive function tests and work type tests that replicate administrative tasks alongside a POE environmental evaluation on two days of each week over 8 weeks in summer. Passive interventions were placed in the two offices in the form of differing solar shading strategies to produce contrast in operative temperatures and lighting levels within the rooms. Window openings and air ventilation was controlled. The findings are briefly presented and discussed in this paper.