Development of a database of low energy homes around the world and analyses of their trends

This study aims to develop a database of low energy techniques for homes around the world, for use in systematically evaluating the low energy home in each region, where climate, culture and policy differ. First, a database was made for the purpose of the systemizing passive and active techniques. Data were input according to seven chapters and 155 items, and 66 homes in 17 nations have been recorded. Homes adopting super insulation, high airtightness and solar energy utilization are common in the each country. The thermal insulation performance of wall and window of the housing in Japan is somewhat inferior to that overseas. It was shown that exhaust heat recovery is rarely adopted in Japan and that the underground thermal energy utilization was seen in less than 10% of recorded homes. Second, recorded homes were categorized according to characteristics of adopted strategies, and the reduction rate of purchased energy versus the purchased energy for a typical home was calculated. This revealed the purchased energy reduction rate of homes with both solar heat utilization and photovoltaic power generation to be very high.