The combined effects of many different indoor environmental factors on acceptability and office work performance

Ninety-nine young-adult subjects of both genders were randomly assigned to four groups. One group performed simulated office work for two hours in a set of poor environmental conditions, with overhead fluorescent lighting, recorded traffic noise from a busy street, 27 degrees C (80.6 degrees F) operative temperature, supply air polluted by emissions from linoleum, recorded open office noise, and almost no daylight. The realistic annual cost of improving each of the six conditions was estimated and expressed as a percentage of the total sum of the cost of improving conditions. The modifications included improved lighting, barely audible traffic noise, operative temperature of 22 degrees C (71.6 degrees F), clean air, quiet, and a daylit view out. A second group briefly experienced all 12 conditions and individually selected the improvements they preferred, up to a 50% budget. A third group of subjects was randomly paired with each of the subjects from the second group, and each pair was exposed to the conditions selected by the second-group subjects. A fourth group was exposed to fully-improved (100% budget) conditions. Significant improvements in subjective assessment occurred at higher budget/individual choice levels, and the self-reported performance of office tasks improved, although measured performance could not be shown to differ significantly between treatment groups.