摘要：The building sector represents on a worldwide level, one of the larger energy consumers that should reduce its negative impact on the exterior environment. On a European level there are several directives that promote the transition to a decarbonized building sector that can be achieved by promoting the design and energy retrofit activity into nearly Zero Energy Building. The 2020 Climate and Energy Package, the 2030 Climate and Energy Framework and the 2050 Long-Term Strategy have the same goal, of cutting greenhouse gas emissions to admissible levels. In the United States the US Department of Energy alongside with the National Institute of Building Sciences set several targets for the development of a very energy efficient building stock. Thus, the paper offers an overview of the energy legislation implementation in European countries and in the United States, with a focus on identifying similarities and differences between the two regions. The first focus of the paper is on technical or legislative aspects identified in Europe and the United States in promoting nZEBs. Second, the definition of nZEB and its progress will be discussed and third several case studies will be discussed with the aim of identifying key points in achieving nZEB levels.
