Over the last few decades, research in public health has associated inactivity with a number of ailments and chronic diseases, such as colon cancer, type II diabetes, osteoporosis and coronary heart disease. In the belief that the office building substantially shapes occupant daily activity, this work draws upon qualitative and quantitative monitoring of human activity within office buildings during typical working weeks. This research is based on data collection results regarding the design of space in relation to energy expenditure and it presents a quantitative model (named KINESIS after the Greek word for activity) that, in the form of a set equation, can simulate and estimate the total energy expenditure per person per day in a given office layout.