With a low rate of new building construction and an insufficient rate of existing building renovation, there is the need to step up the pace of building renovation with ambitious performance targets to achieve European Union (EU) climate change policies for 2050. However, innovative technologies, including, but not limiting to, plug and play (PnP) prefabricated facades, information and communications technology (ICT)-support for building management systems (BMS), the integration of renewable energy systems (RES), building information model (BIM) and building performance simulation models (BPSM), advanced heating, ventilation, and air conditioning (HVAC), advanced geomatics, 3D-printing, and smart connectors, cannot alone solve the problem of low renovation rates of existing buildings in Europe that is hindering reaching of EU-wide targets. A workshop was held at the Sustainable Place Conference 2018 to present, with an integrative approach, the experiences from four H2020 innovation actions, i.e., 4RinEU, P2ENDURE, Pro-GET-OnE, and MORE-CONNECT, which were united by their central aims of improving building energy performance through deep renovation practices. This article presents the outcomes of the joint workshop and interactive discussion, by focusing on technical, financial, and social added values, barriers and challenges, in the context of the building renovation processes tackled by the four projects. Conclusive remarks converge on the identification of open questions to address future innovation opportunities, as well as some recommendations to be used at a policy level and/or in future implementation projects.

Nearly Zero Energy Buildings (nZEBs) represent the backbone to achieve ambitious European goals in terms of energy efficiency and CO2 emissions reduction. As defined in the EPBD, by 31 December 2020, all of the new buildings will have to reach a target of nearly zero energy. This target encourages the adoption of innovative business models as well as the technology development in the building sector, aimed at reducing energy demand and exploiting local renewable energy sources (RES). Assessing the share of implementation and the performance of technologies in new or renovated nZEBs is strategic to identify the market trends and to define design guidelines with the most effective solutions according to the context. In this regard, this paper analyses the construction features of a set of nZEBs, collected in 17 European countries within the EU IEE ZEBRA2020 project, with a special focus on the influence of the boundary conditions on the technologies adopted. The results show a general high insulation level of the envelope and recurrent specific technologies in the Heating Ventilation Air Conditioning (HVAC) system (i.e., heat pumps and mechanical ventilation), while the climatic conditions do not drive significantly the design approach and the nZEB features.

The last release of the Energy Performance of Buildings Directive 2018/844/EU stated that smart buildings will play a crucial role in the future energy systems. Consequently, the Directive introduced the Smart Readiness Indicator in order to provide a common framework to highlight the value of building smartness across Europe. The methodology for the calculation of the Smart Readiness Indicator is currently under development and therefore not yet officially adopted at the European Union level. In this context, the current research analyzed the second public release of the proposed methodology, discussing the feasibility of its implementation and the obtained results through a practical application. Specifically, the methodology was applied to a nearly zero-energy office building located in Italy, and the evaluation was carried out in parallel by two different expert groups composed by researchers and technical building systems specialists. With the aim of analyzing the impact of subjective evaluations on the calculated indicator, a two-step assessment was adopted: in a first phase the two groups worked separately, and only in a second phase they were allowed to compare results, discuss discrepancies and identify the difficulties in applying the methodology. As the main outcome of this research, a set of recommendations are presented for an effective broad implementation of the Smart Readiness Indicator, able to increase the relevance of its evaluation and effectiveness, as well as to enhance the comparability of smart readiness of buildings through the definition of benchmarks and to integrate with other measurable key indicators, especially concerning energy flexibility.