Presents the first of three papers summarising the results of a survey undertaken to collect and systematise information on quantitative relations between the indoor air environment and worker productivity. Describes three recent large studies of office worker productivity, discusses productivity measurements and relates productivity to building costs. Finds general agreement that improved working conditions tend to increase productivity, but that determining a quantitative relationship between environment and productivity proved to be highly controversial. Concludes that since the cost of people in an office is an order of magnitude higher than the cost of maintaining and operating the building, spending more money on improving the work environment may be the most cost-effective way to improve worker productivity.KEYWORDS: Personnel, offices, productivity, environment, comfort, psychology, costs, temperature, indoor, air quality, sick buildings, offices, factories, industrial