Abstract-Due to the large, heterogeneous audience of Web applications, and its rapidly changing expectations, holistic requirement analysis approaches are crucial to ensure the success of Web engineering projects. To increase the quality of resulting Web applications, non-functional requirements (NFRs) must be considered. Satisfying them is a non-trivial task that depends on making decisions about which functional requirements (FRs) to implement, and how to prioritize the NFRs. A satisfactory solution is a trade-off, where competing NFRs must be balanced. In this paper, we outline how the Pareto efficiency can complement a goal-oriented requirement analysis modelling to evaluate and select optimal configurations of requirements for a Web application, while NFRs are balanced and maximized according to a priority list. We hereby focus on an empirical evaluation to verify whether our Pareto method improves the accuracy of design decisions during the requirements analysis phase, and/or if it reduces the time needed by designers.