This chapter presents the results of two consecutive research studies related to individual control of the microenvironment and human performance. First, it briefly describes the results of a year-long study of the emerging developments related to individually controlled environmental systems (environmentally responsive workstations, ERWs1) and their associated technologies. Second, it presents the results of a year-long field study related to ERWs and worker productivity conducted at an insurance company in the northern Mid-west of the United States. The study revealed a statistically significant positive association between the change in productivity and the change in ‘overall satisfaction’ with the workspace (Kroner et al., 1992). Researchers found that improved indoor architectural and environmental design contributed to an overall increase in productivity of 16 per cent. ERWs were estimated to increase the level of worker productivity by approximately 3 per cent.