Pervasive Computing envisions seamless and distraction-free support for everyday tasks through distributedapplications that leverage the resources of the users' environment. Due to the mobility of users and devices, applications need to adapt continuously to their changing execution environment. Therefore, developers need a suitable framework in order to efficiently create adaptive applications. In this paper, we present and evaluate our approach to adapting a pervasive computing application to changes during its execution. This work is based on the minimal component system PCOM and on an algorithm to fully automate the initial configuration of a componentbased application which we have presented in earlier work. The contribution of this paper is threefold. First, we describe a number of modifications to the component model that are required to enable fully automatic adaptation. Secondly, we propose a simple yet powerful cost model to capture the complexity of specific adaptations. Thirdly, we describe an online optimization heuristic that extends our distributed configuration algorithm in order to choose to a low-cost configuration whenever the current configuration of a pervasive application requires adaptation.