Abstract. We explore and discuss different ways of expressing service specifications in the context of home automation systems implemented on OSGiTM. We found that the approach used for expressing services affects the amount of service interaction in the system. Some approaches, as opposed to others, artificially increase the number of situations where services are considered to badly interact. We discuss the pros and cons of three approaches for service specification in the context of the home. Keywords. Home automation, specification, JML, OSGiTM, iPOJO