Energy demand in the built environment is quite important. China holds a large population and the energy use in the building sector is about 1/3. The rebuilding of old houses and building new low energy houses are becoming more and more popular in China. Low energy building not only consumes less energy, but also provides good indoor environment.

An indoor climate software IDA is used in energy and indoor climate simulation. The traditional high isolated low energy house in a hot climate is analyzed, on a typical day in either summer or winter, or during the whole year. Energy consumptions under different parameters are presented. Results show that high isolated house may not always be suitable in a hot climate.