Smart buildings automation faces interoperability, privacy and scalability challenges. Home automation tools such as Home Assistant have been designed with these goals in mind. In this paper, we describe our smart laboratory configuration using Home Assistant and how we leverage custom entities to store and publish both raw data as well as processed information. Our goal is to achieve some level of ambient intelligence and we demonstrate it with two use cases. First, we show how facial emotion recognition can be integrated with our setup. Second, we describe how air quality data collected by Home Assistant can be used to estimate the number of occupants in the lab.