A Harvard University led multidisciplinary team investigated the decision making performance of 24 participants (architects, designers, engineers, managers, programmers) monitored over 6 days in a climatically controlled office environment. Utilising a double-blind study, the researchers studied the impact of ventilation, chemicals, and carbon dioxide on workers’ cognitive function in representative ‘non-green’ vs. ‘green’ buildings.

Comparison between typical ‘non-green’ and ‘green’ office workspace was undertaken by exposing the participants to elevated levels of volatile organic compounds (VOCs) and carbon dioxide (CO₂). Testing was then conducted to investigate any impairment of cognitive performance.

The findings indicate that overall those participants from the ‘non green’ workspace conditions performed at a significantly lower (<50%) cognitive level that those participants from the ‘green’ and ‘green+’ conditions.

Investigating further the impact of VOCs, CO₂ levels and ventilation rates in the ‘green’ and ‘green+’ workspace conditions, the researchers found significant performance improvements in the participants’ higher cognitive functions, related to:

• Crisis response (97% ‘green’ and 131% ‘green+’)
• Strategic solutions (183% ‘green’ and 288% ‘green+’)
• Information usage (172% ‘green’ and 299% ‘green+’)

Cognitive scores were 61–101 % higher in green buildings compared to conventional building (p < 0.0001). VOCs and CO2 were independently associated with cognitive scores. In conclusion, the researchers comment that even a modest improvement in indoor air quality could have a dramatic improvement on workers decision making and overall cognitive performance.