Houses are unique personal spaces and individuals want flexibility and personalization in building their dream house. There is a current challenge in the prefabricated housing industry in Sweden where customers have increasing design demands and options that in essence, defeat the purpose of fixed design and prefabrication. This causes strain to both the customer and the company’s design process and sustainability efforts. The purpose of the study is to map the customer demands in customization of prefabricated houses through the innovation process of ideation, realization, and implementation. The overarching strain in customization is due to (1) the complexity of choice in designing a house, and (2) the mismatch between customer demand and manufacturing capability. A design criteria with BIM was brought forward to aid in the customization process in being more objective for decision-making. Through a case project and a design criteria, a prefabricated house model was redesigned with maximized flexibility. The findings in this study is a contribution to the house manufacturers in Sweden as an aid in architectural design and client communication strategies.