Nowadays there are sound Model-Driven Development (MDD) methods that deal with functional requirements, but in general, usability is not considered from the early stages of the development. Analysts that work with MDD implement usability features manually once the code has been generated. This manual implementation contradicts the MDD paradigm and it may involve much rework. This paper proposes a method to elicit usability requirements at early stages of the software development process such a way non-experts at usability can use it. The approach consists of organizing several interface design guidelines and usability guidelines in a tree structure. These guidelines are shown to the analyst through questions that she/he must ask to the end-user. Answers to these questions mark the path throughout the tree structure. At the end of the process, the paper gathers all the answers of the end-user to obtain the set of usability requirements. If it represents usability requirements according to the conceptual models that compose the framework of a MDD method, these requirements can be the input for next steps of the software development process. The approach is validated with a laboratory demonstration.