At least twelve Large Scale Manipulators (LSMs) have been developed in recent years to perform tasks as diverse as concrete pumping, piping erection, and rebar placement. Most of these LSMs are still at a prototype stage, and further developments are necessary to successfully commercialize LSM technology. Determining functional requirements is critical for these developments. This paper presents a method for determining functional requirements for LSMs in construction. The method consists of (1) establishing sets of functional characteristics for a prototype LSM, (2) determining the usefulness of the LSM with each set of characteristics for a type of project, and (3) establishing the most desirable set of functional characteristics as requirements for future developments. The University of Texas LSM is used as a primary example to illustrate the method. It is concluded that LSMs have the potential to increase safety and productivity and that development of more advanced control systems and of multi-functionality will help ensure that this potential is realized.