An automated monitoring system characterised as a smart house and called the Welfare Techno House (WTH) has been designed for home health care to prevent disease and improve the quality of life in the elderly. In this paper, we describe the smart house project in Japan and evaluate its effectiveness. The WTH concept involves a monitoring system for the continuous measurement of physiological parameters. Using this system, we collected physiological data and then analysed the key features of the data with regard to health monitoring. We review the previous 10-year trial of the WTH experimental project and discuss future developments.