Activities involving the possession and use of radioactive material require the application of controls to ensure the health and safety of the worker and general public. One of the first steps in adequately controlling any licensed activity is the establishment of zones and boundaries that will exist for purposes of restricting or regulating personnel radiological exposure. Title 10 of the Code of Federal Regulations, Part 20 (10 CFR 20) defines the "restricted area" (RA) and prescribes the administrative and radiological protection controls pertinent to the RA. For nuclear power facilities, the determination of the physical relation of the RA boundary with other physical or administrative boundaries, such as the site boundary, the radiologically controlled area (RCA), and the exclusion area boundary, must be based on an evaluation that considers all applicable federal requirements and limits for each zone or boundary contained within or interfacing with the RA. This paper presents a discussion of the factors that should be considered and an evaluation methodology that can be utilized based on the generation of two-dimensional isodoses.