Participatory design (PD) activities in private homes challenge how we relate to the PD process, compared to PD in professional settings. Grounded in a project related to chronic dizziness among older people, we identified four challenges when performing PD with ill, weak users in their private homes. The challenges are (1) designing for, and negotiating knowledge about, the home, (2) ill, weak users and their participation in PD, (3) divergent interests of participants and (4) usable and sustainable post-project solutions. These challenges have to be carefully addressed, and we use them to reflect upon differences between a home-based PD process with non-workers, such as ours, and work-place projects, such as Utopia. Through this reflection, the paper contributes to a more general discussion on PD in non-work settings with weak users. Indeed, differences do exist between traditional PD projects in work settings, such as Utopia, and home-based PD with weak users especially in relation to knowledge about settings and how to reconcile differences in interests. The home as a place for (technology-assisted) treatment and PD must be carefully analyzed. Diverse interests and roles as well as possibilities for post-project solutions should be negotiated among all stakeholders.