In the last 50 years a fifth of the planet’s inhabitants had a strong development that deeply changed their habits and their life quality. For this enhancement, the people of the developed areas paid a high price. A large use of energy, produced from non-renewable sources as fossil fuels, increased the carbon dioxide (CO2) emissions into the atmosphere with several problems and a huge impact on the nature. As a consequence, there is a need to rethink the design of buildings, cities and their organizations. The challenge for the new sustainable cities is to grow according to the lifestyles of today and tomorrow, while implementing a better relation between the nature and the mankind and restoring the lost human contacts. An option for doing this is to design and develop Zero Energy Homes (ZEH) reducing to the minimum the impact of pollution and the exploitation of non-renewable sources. In particular, the following aspects should be considered: to use of renewable and recycled materials; to improve the energy efficiency of buildings; to introduce more efficient energy systems that use alternative and clean sources; and to introduce building automation systems (to optimize the energy consumption). In this lecture the following topics will be presented: definition of ZEH, including a review of definitions, parameters influencing the definition and examples, criteria to build or refurbish to a ZEH standard and some questions and examples related with the design, construction and operation of new Zero Carbon Homes.