Most real world engineering design optimisation approaches reported in the literature aim to find the best set of solutions using computationally expensive quantitative (QT ) models without considering the related qualitative (QL ) effect of the design problem simultaneously. Although the QT models provide various detailed information about the design problem, unfortunately, these approaches can result in unrealistic design solutions. This paper presents a soft computing based integrated design optimisation framework of QT and QL search spaces using meta-models (Design of Experiment, DoE). The proposed approach is applied to multi-objective rod-rolling problem with promising results. The paper concludes with a detailed discussion on the relevant issues of integrated QT and QL design strategy for design optimisation problems outlining its strengths and challenges.