The COVID-19 pandemic posed a challenge for all confined populations, dealing with their home resources and suffering changes in their psychological well-being. The aim of this paper is to analyze the relationship between home conditions (i.e., having children, square meters of the house and square meters of the terrace or similar) and psychological well-being, and to test whether this relationship is mediated by Internet addiction and nostalgia. The sample was composed of 1509 people, aged between 18 to 78 years (67.6% women). Structural Equations Models and 2 × 2 ANOVAs were analyzed. It was found that better home conditions mean greater psychological well-being, and that this relationship is partially mediated, in a negative sense, by Internet addiction and nostalgia, especially after day 45 of confinement and with greater intensity in women. These results provide evidence about how psychological well-being can be preserved during a confinement situation, which may be useful for planning healthy strategies in similar circumstances in the future.
