This study was designed as a bottom-up approach to understanding what kind of changeable functions people desire in transformable garments by analysing a wardrobe database, participants' perceptions of garment varieties, and participants' values related to transformable garments (specifically tops, the wardrobe garment with the most observed design variability). The wardrobe database was analysed using data quantification and descriptive analysis. Style-conscious professional women, ages 20-40, were interviewed; their perceptions and values related to design variability in tops was the focus. Versatility was the most important reason for preferring specific changeable design functions. Among candidates for changeable design functions, the most preferred functions were transforming colours or patterns and sleeve lengths. Participants had three expectations for transformable garments: functional (ease of matching, ease of layering, comfort, usability, ease of care, and durability), hedonic (fun and be able to experiment with various styles), and social (context aptness and modesty).