From high performing buildings to nearly zero energy buildings: potential of an existing office building

The EPBD recast establishes that by the end of 2020 all new buildings must be nearly zeroenergy buildings (nZEBs), that are defined as buildings with a very high energy performance and that require a nearly zero amount of energy, a very significant extent of which should be covered by renewable sources. As no minimum harmonized requirements are fixed by the EU Directive, on this regards, the US high performing buildings represent a starting point to look at as a reference. The aim of this paper is to some guidance to EU Member State into nZEB roadmap by examining a set of US high performing buildings. Especially the energy performance of an existing high performing office building was analyzed by means of dynamic energy simulation and additional efficiency solutions have been applied to it in order to adapt it to the current day and to make it converge towards a nZEB.