Within sustainable development one strives for structures with a minimum volume of material. At conceptual design stage a clear hierarchy among different structural morphologies can be established with Morphological Indicators (or MI). MI are dimensionless numbers that represent a property of a structure (e.g. its volume) and only depend on a reduced number of variables, providing user-friendly and efficient tools to guide students, architects or engineers, during their comparison of different structural types. Till now MI privileged resistance as the prior design constraint. This book shows that stiffness and stability problems can require important additional structural modifications. New indicators are introduced to include more design criteria: predicting global planar instabilities, assessing (pedestrian induced) vibrations and reducing them with tuned mass dampers. The application of different optimisation methods, based on numerical algorithms, on practical examples confirms the high efficiency of MI when strength dominates the design but also emphasizes the need for alternatives when stiffness or stability dictates it.