Description of each usability issue.

<div><p>This research addresses housing customisation by using digital tools in co-design processes. This paper introduces the development of a Graphical User Interface (GUI) that assists the end-users’ interaction with the design process. Although the participation of end users in the design process is considered essential, a communication gap persists between designers and end users, and there is a lack of tools to help inhabitants express their needs and desires. To bridge this gap, this research proposes using digital technologies to enhance end-users participation in the design process of their houses. In this paper, we show the results of the development and evaluation of an interface designed to help inhabitants to co-create their houses. We developed and tested a GUI for a housing co-design system. Interviews with professionals, housing cooperatives, and inhabitants informed the design process, allowing us to define user requirements and design tasks. The interface was tested with low and high-fidelity prototypes, receiving positive feedback from both experts and potential users. Architects were also involved in using the interface to comment on its usefulness for housing co-design. The tool demonstrated the potential to improve end-users’ participation, contributing significantly to participatory processes in collective housing. This research ensures the tool’s effectiveness by directly incorporating user input, aligning the interface with the user’s needs and preferences.</p></div>