Inside the Study

The new study examines cognitive function in 109 office workers across 10 high-performing office buildings in five U.S. cities differentiated by climatic regions. High-performing buildings are defined as those surpassing the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) standard for acceptable ventilation and indoor air quality and with low total volatile organic compound (TVOC) concentrations.

Participants were studied for one week, with researchers testing cognitive function on Tuesdays and Thursdays.

Cognitive function was tested using the Strategic Management Simulation (SMS) software. The SMS is a 1.5 hour, validated cognitive assessment test that has been used by more than 70,000 participants worldwide over the last seven decades.

The tool presented participants with a real-life scenario, where they had to respond to several plot lines that emerge over the course of the simulation. It gave participants the freedom to make decisions based on their own cognitive styles and is reflective of their performance in the real world.

In addition, participants' sleep quality was tracked each night through the use of wearable sensors. They were also asked to complete surveys about their health and environmental perceptions. Completed each study day, for a total of five times per participant, the health assessment examined the occurrence of 19 sick building symptoms. On the final day, a third type of survey was administered, which assessed satisfaction with the indoor environment – from noise and lighting to thermal comfort and odors.

Finding the total impact of green buildings on cognitive function



1 week

per building

10 office buildings, all high-performing buildings

Office Buildings

All High-performing Buildings1
6 out of 10 green-certified buildings
Green-certified buildings2

5 U.S. Cities
Differentiated by Climatic Regions

  • San Jose, CA
  • Los Angeles, CA
  • Denver, CO
  • Boston, MA
  • Washington, DC

Cognitive Function Tests
performed on Tuesday and Thursday

Health Assessment

Sleep Patterns

A survey regarding perceptions and symptoms

Occupants of green-certified, high-performing buildings saw

26% Higher Cognitive Function Scores

Higher Cognitive Function Scores

Slept better and reported fewer health symptoms

compared with those in similarly high-performing buildings that were not green certified.