In this paper, design of a zero energy building (ZEB), a case study for Tehran, in a moderately warm climate, for a typical single family has been introduced. It is important to develop solar energy resource potential in order to use it in construction of enhanced buildings. The benefits including reducing fossil fuel consumption, fading energy supply cost and lowering environmental pollutants, have created a growing tendency to these types of buildings. Calculating solar energy radiation and the house load are the basic steps to design a ZEB. Following steps are designing the heating, cooling and domestic hot water (DHW) systems and providing the electricity for appliances and lighting and designing the storage system. Economical features and environmental issues make ZEBs an appropriate solution for emerged problems of common houses and thus investments in large (state-wide) scales may be justified
