The nearly decoupled design of time-invariant multivariable control systems is discussed. Part 1 deals with single-loop control systems design while Part 2 deals with multi-loop control systems design. In particular, Part 1 initially considers the case where the given plant has an equal number of inputs and outputs before exploring the case when a plant has more inputs than outputs. As a direct generalization of the classical approach, the proposed approach offers the designer the ability to choose the structure and specification of the compensator so that a trade-off between the cost and the performance of candidate designs can be made. Furthermore, it is shown that, when the plant has more inputs than outputs, the extra inputs can be used to reduce the required control effort without sacrificing the achieved performance. An optimization-based approach is then proposed to make the best use of the extra inputs.