From nearly zero energy buildings (NZEB) to positive energy buildings (PEB): The next challenge - The most recent European trends with some notes on the energy analysis of a forerunner PEB example

The European energy policies introduced the Nearly Zero Energy Building (NZEB) objective (Directive, 2010/31/EU and 2018/844/UE) to stimulate the energy transition of the construction sector. EU programs, specifically “Horizon 2020”, promote the NZEB design and also its evolution, namely the Positive Energy Building (PEB) model. Based on the most recent developments, a critical review of the main actions of the European Union towards the development of the NZEB and PEB design models has been conducted. Some considerations on advanced materials and technologies (PCM, VIP, smart glass, integrated photovoltaic systems) have also been added. Finally, a case study is presented (single-family residential NZEB) to show how a careful and integrated design of the building envelope and systems not only allows to obtain an almost total coverage of the energy consumption by renewable sources, but also to generate an energy surplus that could be shared with urban grids (PEB potential). •Some of the most recent developments on the nearly zero energy buildings are resumed.•The European actions to promote, increase, and monitor NZEB diffusion, are indicated.•The next challenge, the Positive Energy Building and its diffusion is outlined.•The calculated and monitored energy consumption of a precursor NZEB are compared.