A multiagent system uses argumentation-based interaction in an ambient-intelligence context to provide services for people with different combinations of impairments. This paper focuses on ambient intelligence system of agents for knowledge-based and integrated services for mobility-impaired users integrated projectpsilas (ASK-ITIP) furthered the challenge by aiming to support users having different types and combinations of impairments. ASK-ITIP use of argumentation to model a distributed decision-making process for a coalition of assistant agents, each an expert on a different impairment. When a user suffers from a combination of impairments, these agents engage in an argumentation-based dialogue to agree on the user's needs. We found that applying argumentation was natural in this context because, generally speaking, we can abstractly define argumentation as the principled interaction of different, potentially conflicting arguments to obtain a consistent conclusion. Moreover, argumentation-based interaction is combined with a standardized interaction type based on the foundation for intelligent physical agents interaction protocol.