Design is complex. This is because it involves conflicting goals that are often vague. Also, prior to the design it is generally not clear how important goals are relative to each other. And finally the amount of possible solutions is large in general. These bottlenecks are addressed in this thesis. A novel approach for design is proposed, where computation is used to reach most suitable solutions. The approach is based on a novel concept of the objects forming a design. This concept is termed intelligent design objects. Such objects exhibit intelligent behavior in the sense that they approach most desirable solutions for conflicting, vague goals put forward by a designer. That is, the objects know ‘themselves’ what to do to satisfy a designer’s goals. This is accomplished using methods from the domain of computational intelligence, as these are uniquely able to deal with the complexity of design mentioned above. The result from the approach is that designers and decision makers have great certainty about the satisfaction of their goals and are able to concentrate on second order aspects they were not aware of prior to the execution. The approach is implemented for two applications from the domain of architecture demonstrating its effectiveness. The thesis addresses to students, researchers and executives in the field of architecture, and other areas of design. It may be also interesting for researchers in the domain of computational intelligence, as it provides a formalism of intelligent design, and it exemplifies the use of these modern technologies in the design domain. Due to its generic nature, this formalism may have some significance in the development of the science of design.