Setting the sustainable transition in motion implies reflecting on all areas linked with human activities and in all types of organizations. This transition has been examined in research for many industrial activities, however a reflective positioning on the environmental impacts associated with professional activities, and notably research ones are scarce. Researchers produce knowledge that should hopefully benefit the human society in a broad sense by bringing some benefits (technological, ecological, social, economic…), but they also engage activities that have themselves an environmental impact. Although research activities vary depending on the domain, common core activities include for example professional travels (including conferences) and the use of digital resources. Moreover, there is an acknowledged potential in transferring environmental practices from home to work (or vice versa), related to waste, food, energy or mobility for instance. The aim of this study is to conduct a first environmental diagnosis of research activities at the scale of a research department, with a specific zoom on attending conferences and other business travels. The empirical work involves 9 volunteering researchers over a period of 3 months, and is built on a declarative basis. The environmental impact (GHG emissions) of declared professional expenses (transportation, accommodation and meals) is estimated based on their nature and economic value. From the diagnosis we derive a set of recommendations and action plans to support the transition towards sustainable research practices.