COVID-19 significantly impacted residents’ health status and daily activities in suburban residential areas. This study elucidated the relationship between health scores, daily activities, and housing types. The method was a questionnaire survey of 378 residents of suburban residential estates in Teraikedai, Kongo District, Japan, during the COVID-19 self-isolation period. Since the survey cohort was New Town, the suburban residential area identified by the Ministry of Land, Infrastructure, Transport and Tourism was targeted. The questions included participant demographics, the Basic Survey on Japanese Social Life, and the SF-12v2. The Tukey–Kramer HSD test and stepwise decreasing logistic regression were used for the statistical analysis of the responses. The COVID-19 self-isolation led to lower physical and mental health scores than usual, and the health scores of residents living in detached houses were better than those of residents in apartments, both those over the age of 65 and those under the age of 65. There was also a correlation between residents’ daily activities and their health scores. For those aged under 65 years, the health scores of residents living in detached houses were significantly better than those living in apartments, indicating that daily activities such as sports and recreational hobbies may contribute to health scores.