The construction job sites are regarded as highly dynamic and chaotic environment for both workers and management. To ensure efficient task performances, workspace is a key resource in construction sites. Nowadays the technology has enabled better management of onsite resources through location-based methods within lean construction principles, such as Location-Based Management System (LBMS) and Takt planning. Those methods aim to optimise workspace in construction sites consisting of multiple tasks and to eliminate waste related to product and labour flows. To contribute to enhancing those lean construction approaches with attempts to obtain real and objective data, we have developed a real-time positioning system based on Bluetooth Low Energy (BLE) technology where coordinates of workers can be obtained, and heat maps of task-related workspace are generated in real time. This paper aims to develop automated process of generation of workspace based on coordinates of workers and to explore various uses of workspace heat maps to serve the purposes of lean construction principles. The successful implementation of the system in China is analysed and the results suggest that heat maps which use dimensional and temporal positioning data, could be an efficient and convenient method to define workspace of crews onsite.