Refurbishment Scenario to Shift Nearly Net ZEBs Toward Net ZEB Target: An Italian Case Study

The idea of a Net ZEB arises from the development of design criteria and construction methods, addressed to curb the operating energy, increasing the energy efficiency of building equipment and appliances, and of the thermal insulation of envelope components, and enhancing the on-site energy generation, by means of renewable sources, to cover the annual building energy loads.In this Chapter the energy and environmental performances of an Italian nearly Net ZEB, following a life cycle approach is carried out. Then, a scenario of refurbishment is foreseen in order to shift the studied building from the nearly Net ZEB condition toward the Net ZEB target, and the arising energy and environmental benefits are assessed. The life-cycle approach in the energy and environmental assessment of the foreseen retrofit options is necessary to avoid shifting environmental burdens from one step of the life-cycle to another. Further, in order to get a deeper description of the energy performance of the retrofit actions and to compare the different alternatives, the Energy Payback Time and the Emission Payback Time are assessed for the proposed solutions.