Conventional piled foundation is usually designed to provide adequate load carrying capacity and to limit the overall settlement (and hence controlling differential settlement) within tolerable limit. As such, the piles are often of the same length and size. In this paper, a design approach is presented in which the foundation of a medium rise building (5-storeys) is designed using skin-friction piles of different length. The design objective is to control the differential settlement at the onset rather than limiting the overall settlement. The design utilises the interaction between piled raft and soil in order to produce an optimum design which satisfies both the serviceability and ultimate limit states. The presence of the deep deposit of highly compressible soft clay also poses major challenge in the design as negative skin friction, excessive differential settlement and bearing capacity failure associated with such soft materials need to be addressed. A monitoring scheme on the structures has been successfully implemented and the monitoring results have demonstrated that the foundation system coupled with a properly planned temporary surcharging of the earth platform is very effective. The monitoring results will also allow for further improvement and refinement of design.