Boundary conditions are a significant element of a process developing the degressive proportionality principles. With regard to voting issues, this is equivalent to determining a minimum and a maximum representation, and a size of the whole assembly. In case of a practical problem, the choice of these numbers is evidently constrained. The political conditions as well as the necessity of ensuring efficient functioning of the elected body significantly restrict a set of all possible alternatives. The paper analyzes the feasibility of boundary conditions under a given minimum and maximum representation.