Following the experimental homes that used the concept of zero life-cycle-CO 2 (LCCO 2 ) that were built in 2008 and 2009, the first zero-LCCO 2 home was introduced in the market in 2010. The idea of a zero-LCCO 2 home is to reduce the annual energy consumption and increase solar energy use so that photovoltaic (PV) energy generation substantially exceeds the total energy consumption of the home. The remainder of the annual energy balance can be accumulated every year to compensate for the energy required during the manufacturing and construction periods. The annual CO 2 absorption by PV generation exceeds the annual CO 2 emissions owing to energy use. In other words, the LCCO 2 may approach zero over time. In this study, the annual energy use and CO 2 balance of the house were carefully simulated. The embodied CO 2 of the house was also evaluated using an input-output analysis and accumulation method. The results suggest that the material added for better energy efficiency and CO 2 emissions generated during the manufacturing and construction periods have a positive effect on reducing the LCCO 2 of homes.