This study investigates challenges associated with integrating a passenger (PAX) door on complex compound curvature (CCC) fuselages. Aerospace companies are investigating concepts that no-longer have constant cross-section (CS) fuselages.The PAX door is based on a generic semi-plug door for a long range business jet (BJ). This study investigates limitations of locating the door by varying the transition zone angle. A parametric CATIA tool, coupled with the use of finite element model (FEM) results can highlight key drivers in the design and location of PAX doors, creating a first-draft structural layout. The associated impact on the design and structural architecture for a fold down PAX door with integrated stairs is discussed.The impact of CCCs on the PAX door design is investigated with consideration to location, kinematics and function of the door. Design requirements, when coupled with stress analysis to simulate pressurization effect of the load applied to the stops, can create a powerful tool. Combining the architectural layout, design requirements and top-level stress analysis can be used to define limit curves and understand key design drivers that impact the door position, with reference to weight, design and human factor constraints.The design conclusions to-date suggest for a transition angle above 5 degrees, the structure is too complex to use a traditional frame and lintel design and will be an interesting case for bird impact. Below 5 degrees is the limit for conventional door and kinematic designs in-line with frames.