Modern functional buildings are equipped with building and room automation systems containing tens of thousands of devices. In the future these systems will be much more complex due to the increasing users' demand as well as the variety of available technologies. In practice, the process of planning such component-based systems is highly complex, due to the large number and variety of components available on the market. System designers, who currently design these systems manually, are no longer able to have a complete overview of all available components. In this paper an extension of an existing multi-step approach for component selection process will be described, which reduces the exponential complexity of the component selection problem. This extension uses an analysis of criteria imposed on the design task, thereby restricting the search space to a minimum. Various tests showed the complexity reduction capability of the algorithm, as well as its dependency to the number of defined criteria.