The application of sequential planning to the design process is discussed, considering design as a search through a space of states. The procedures which transform states utilize a kind of design knowledge. Planning is considered as a method of controlling the design process. Various paradigms of planning are discussed along with their application to design. The authors discuss forward deduction and backtracking, backward deduction hierarchical planning and constructive approaches to planning. These lead to the view that control in design is a multi-level process. The paradigms are illustrated with examples implemented in PROLOG. With this it is shown that knowledge-based planning is a good design paradigm