This study explored ways of changing a detached house which has older residents to a universal design home. This study investigated the residential conditions based on the universal design features and the need of universal design for aging in place. For this study, 153 residents who were living in single detached houses in Columbia, MO, were surveyed using written questionnaires and interviews. Primary findings of residential conditions were showed according to each spaces such as entrance, interior hallway, master bedroom, bathroom and kitchen. The major results are as follows: 1)It was confirmed that major spaces for daily living such as a bedroom, bathroom, kitchen and laundry facilities needed to be on the ground floor. 2)The most dangerous spaces in house were stairs to the upper or lower floors and the bathroom, 3)The need for modification based on universal design were high in order to facilitate aging in place. 4) Finally, elderly people in their seventies had especially strong needs through modification compared to the elderly people in their sixties who had plans to relocate.