The development of new enabling devices is one of the most credible short and medium-term applications of brain-computer interfaces (BCI). Unlike many other recent assistive technologies (AT), present BCI systems usually do not result from a "design for all" approach, since they are mainly effective for people suffering from severe motor disabilities. However, many authors have shown that it is crucial to take into account adaptability, flexibility, customisability and other ergonomics related criteria while designing a BCI-based AT. In this paper, we specify a framework that could expedite the transferability of BCI experiments from labs to clinical departments and later to patients' homes. We highlight the interest of designing dedicated experimentation facilities (namely a Room for BCI Experimentation or RBCIE) in which the developed BCI systems can be efficiently tested and validated. More generally, we highlight the interest of a multidisciplinary design approach introducing human factors at the core of concerns.