In interacting shear wall and flat slab-column construction it is desirable to be able to evaluate the contribution of the columns to the stiffness of the lateral load resisting system. This paper presents a relatively simple method whereby this contribution can be determined, both in terms of the reduction in lateral displacement and the reduction in overturning moment in the shear walls. For the case of a continuous flat slab connection, the bending of the slab induces axial forces into the exterior columns, which therefore causes a portion of the moment to be carried by the columns. Axial forces can also be induced into the exterior columns by means of a very stiff top beam extending from the shear wall to the exterior columns. Design curves are presented for both types of stiffening so that the method can be applied easily by the designer. Comparisons of specific examples with results obtained by a more exact computer-oriented method show that the method gives reliable results.