For successful implementation of the New Ways of Working (NWW) office, it is necessary to plan on the basis of user-identified space usage information. Of the different methods, a trilateration-based Bluetooth low-energy (BLE) Beacon system has a greater potential as it provides specific location information. However, the feasibility of implementing a trilateration-based BLE Beacon system has not yet been validated in space-usage analysis in the NWW office. The present study thus aimed to establish whether such a system would be suitable for the purpose. Two sets of experiments were performed in an open-plan office in order to evaluate system accuracy. The present study used two indexes: Distance Difference (DD) and Accuracy Rate of User-Identified Location Estimation (AR). The best average DD was 0.7 m at desk 5 in the first experiment, which is promising. However, the overall experimental DDs were 1.63 m and 1.93 m, while both DD and AR showed significant variance between desks. These findings indicate that system accuracy and consistency are not yet sufficient for space usage analysis in the NWW office. Accordingly, to enhance system accuracy and consistency it will be essential to develop strategies for optimal system deployment and to combine them with other methods.