Heterogeneity and dynamicity of pervasive environments require the construction of flexible multimodal interfaces at run time. In this paper, we present how we use an autonomic approach to build and maintain adaptable input multimodal interfaces in smart building environments. We have developed an autonomic solution relying on partial interaction models specified by interaction designers and developers. The role of the autonomic manager is to build complete interaction techniques based on runtime conditions and in conformity with the predicted models. The sole purpose here is to combine and complete partial models in order to obtain an appropriate multimodal interface. We illustrate our autonomic solution by considering a running example based on an existing application and several input devices.