The static linear elastic analysis of spatial shear wall systems with flexible base foundations subjected to lateral loading is considered in this investigation. The discrete force method is adopted, in which the base flexibility is modelled by vertical and rotational springs. The soil and structure were coupled by imposing compatibility conditions along the discrete force method interfaces. The proposed method enforces compatibility of deformation on the relative vertical displacement between adjacent release positions, which are established at assumed contraflexural points of the connecting beams which link the slab together and also at storey level intervals along the intersection lines of adjoining non-coplanar walls. The solution of the compatibility conditions provides the redundant shear forces at the assumed contraflexural positions and the stress resultant solution is completed by statical considerations. The displacement solution corresponding to the stress resultants is then evaluated using the linear elasticity assumption. The objective of the current work is to provide a theoretical treatment of foundation-structure interaction, suitable for implementation in the discrete force method. In addition, the work presents results obtained with the discrete force modelling of soil interaction, and discusses its applicability to some representative problems.