Ubiquitous computing is now mature enough to unleash the potential of Smart Homes. The obstacle is no more about hardware concerns but lies in how inhabitants can build, configure and control their Smart Home. In this paper, we defend the idea that End-User-Development (EUD), which considers inhabitants as makers rather than mere consumers, is an effective approach for tackling this obstacle. However, to unleash its potential, we argue that considering the Smart Home as a big computer composed a sensors and actuators that can be weaved together is not enough. We propose to use Activity Theory as a structuring framework to guide the design of futures EUD systems. We reflect on the lifecycle of devices and services to discuss challenges that EUD system will have to address in the Smart Home context: installation and maintenance, designation, control, development (including programming and testing), and sharing.