A new study published in Environmental Health Perspectives relates that people working in uncluttered offices with very low levels of internal pollutants and carbon dioxide work significantly better than those working in offices that are stuffy.

Prof. Joseph Allen, researchers from the Harvard T.H. Chan School of Public Health in Boston, MA led the investigation on  the effect of "green" versus "non-green" buildings and discovered that working indoor can have an unfavorable effect in the cognitive function, while improved air quality could dramatically increase the mental function performance of workers.

Since the early 1970s, energy-saving designs have contributed to the increase in number of airtight buildings, which have led to poor indoor environmental quality. The air exchange rates in homes have dropped from approximately one air change per hour (ACH) in 1970 to 0.1-0.2 ACH in new homes.

Low-level commercial ventilation provision in the early 1980s influenced the "sick building syndrome," that caused a drop in annual costs and productivity losses due to health symptoms which may have caused by indoor environment factors like humidity, ventilation rate and chemical-emitting materials.

As a result, rating systems for "green" buildings were introduced to lower down the environmental footprint of buildings and boost health by giving design commendations to buildings adopting green design, operation and maintenance. Although these commendations include ventilation, filtration, chemical and pollutant sources, they mostly focus on energy-saving and environmental performance.

Green buildings gain these credits for lower concentrations of particles, nitrogen dioxide, volatile organic compounds (VOCs) and allergens; but carbon dioxide CO2 and air exchange rate are generally overlooked due to the focus on energy efficiency.

The current study's goal is to identify the specific feature of green building design that influences cognitive function, an objective measure of productivity. Researchers examined the decision-making performance of 24 participants from different professions, while working in a controlled office environment.

Professor Allen said that we spend 90% of our time indoors and 90% of the cost of a building are the people in it, but indoor environmental quality and its effect  on health and productivity are often something that we fail to focus on. These findings suggest that even little improvements to indoor environmental quality may have a huge impact on the decision-making performance of workers.