Information Architecture and Feature Driven Development

Does anyone have any thoughts or guidance on how Information Architecture and User Experience Design fit into Feature Drive Development? IA work flows into requirements gathering and analysis as well as into providing structure for the project's mental model. User Experience is not always a specific user-requirement but is frequently something driven by the project team to benefit the customer (as well as other various internal advantages). I believe that these functions are necessary to completing a successful project, I'm still just not sure how to integrate them into the FDD process.

Thanks in advance for your help!

Elizabeth Hill