The execution of any process activity requires a specific space necessary for movement of manpower and equipment, and temporary storage of material. As a result, the conflict between activity space demand, and the available space need to be recognized in the planning and scheduling process. Ignoring such conflict may result in work space congestion, increased crew interference, decreased productivity, decline in work safety, and increased project duration. Several scheduling systems have been developed that acknowledge work space as a constraint in their schedule generation process. However, these systems rely mainly on the user to define and input space demand and availability data for each activity. This paper presents a computer model for automatic generation of activity space demand. The model incorporates a formalized approach to quantify space demand data for any process activity with minimum user interaction.