The object-oriented philosophy abstracts out the essential immutable qualities of the components of the finite element method into classes of objects. It facilitates easy modification capability without creating a ripple effect on the whole program and reduces the necessity of knowledge of the source code to a minimum level. This paper presents a prototype implementation of the development of a flexible computational platform based on an object-oriented approach and its application in a FORTRAN environment, which facilitates use of previously developed components. IDARC3D which is capable of linear and nonlinear, static as well as dynamic analyses of multistory three-dimensional buildings with, or without, energy dissipation devices developed in FORTRAN with conventional programming practices has been transformed to the object-oriented framework. By using the new object-oriented platform, some representative examples were analysed and the results were compared with the well-known software facilities. (C) 2009 Elsevier Ltd. All rights reserved.