For long-lived systems, there is a need to address evolvability, i.e. a system's ability to easily accommodate changes, explicitly during the entire lifecycle. To improve the capability in being able to understand and analyze systematically software architecture evolution, we introduced in our earlier work a software evolvability model and a structured qualitative method for analyzing evolvability at the architectural level - the ARchitecture Evolvability Analysis (AREA) method. As architecture is influenced by system stakeholders representing different concerns and goals, the business and technical decisions that articulate the architecture tend to exhibit tradeoffs and need to be negotiated and resolved. To avoid intuitive choice of architectural solutions, we propose to extend the AREA method and strengthen its tradeoff analysis with explicit and quantitative treatment of stakeholders' prioritization of evolvability subcharacteristics and their preferences on design solutions. Finally, an example is used to illustrate the concept and applicability of the proposed approach.