Since 2002, the Energy Performance of Buildings Directive (EPBD) has set up the path to improve the efficiency gains in the EU building sector, including measures that should accelerate the rate of building renovation towards more energy efficient systems. Under the 2010 EPBD, all EU countries have established independent energy performance certification systems supported by independent mechanisms of control and verification. The EU directive 2018/844 has introduced different novelties and one of these regards the possibility for the Member States, together with the Long-Term Renovation Strategies (LTRS), to introduce an optional Building Renovation Passport Article 2a.1(c), considered as an empowering document that gives more reliable and independent information on the potential for energy savings that is tied up in their buildings. On 14 October 2020, the European Commission launched its Communication and Strategy on the Renovation Wave initiative, intending to double the current Europe’s renovation rate to make the continent carbon neutral by 2050. However, current practices and tools of energy performance assessment and certification applied across Europe face several challenges. In this context, the ALDREN project is a methodological framework that aims to support decision-making and investment in deep energy renovation of nonresidential buildings, based on a set of procedures (modules) that consist in the step-by-step implementation of protocols to assess the energy performance, indoor environmental quality, and financial value of buildings, before and after the energy renovation. The paper presents the ALDREN overall procedure with a focus on the development of the Building Renovation Passport and its application to an Italian office building.

Open innovation has recently emerged as an important concept in both academic research and industrial practice, and it is now also becoming increasingly important in the public policy field due to the innovation challenges in different domains, such as climate change, sustainability, and growth to name a few, but only in some value chains (i.e., automotive, manufacturing, aerospace). According to a report by McKinsey and Co., the construction industry lags behind others in adopting innovations; in fact, less than 1% of the construction industry’s revenue goes back into technology research and development. This work focuses on the current debate on the underdeveloped application of the open innovation (OI) approach to the construction sector. Namely, the foundational question is whether the OI model can be the answer to boosting innovation for the decarbonization of buildings. The research goal is to go a step further by analyzing its internal effectiveness, focusing on introducing and defining the Open Innovation Test Bed (OITB) concept. The study provides a systematic and bibliometric literature review of OI starting from a critical analysis of the concept definition and the evolution of the paradigm from the initial application to the first declination for the construction sector. All the steps analyzed allowed us to make an overall and comprehensive review of the OI concept, which is usually applied to other sectors, considering the ecosystem as the most effective declination of the OI paradigm for OITB development for building envelope solutions, thus providing answers to the two objectives identified in the introduction. Finally, the limitations of prior OI studies and the challenges for the OITB new construction paradigm are discussed, and we make recommendations for future opportunities and approach development to tackle and boost energy-efficient envelope solutions for the construction industries.

Starting from an experimental activity, the paper describes research analysis that has been conducted on a real case construction with the aim to design its adaptation as a nearly zero energy building in three possible alternative scenarios: (i) a lab for students’ activities in the Lecco University Campus of Politecnico di Milano; (ii) an Alpine shelter for the implementation of a sustainable mountain tourism in Zermatt; (iii) an emergency shelter for poor communities in Burkina Faso. The use of an easily disassembled and lightweight steel structure coupled with dry-layered technologies allows a tailor-made envelope design, ensuring high thermal comfort, very low energy use, and limited construction times. The three case studies have been designed starting from the same architectural/structural concept. A detailed analysis, by means of finite element method and dynamic building thermal simulations, has been performed to predict the overall performances of each case study. The results show: (i) high replicability of the concept; (ii) high customization of the envelope technologies; (iii) high energy efficiency; and (iv) high thermal comfort of the architecture. The useful energy requirement in all the three analyzed scenarios is minimized and equal to 14.13, 23.88, and 41.83 kWh/m² year, respectively, for the students’ lab, the Alpine shelter and the emergency shelter. According to this study the energy needs can be covered by renewable energy produced on site, making the architectural concept an interesting modular lightweight solution for a nearly zero energy building with high potential for replicability.