This file is the presentation shown by Gianpiero Evola during his "Energy Talk"  at the EU Sustainable Energy Week.
The talk presented the main challenges and scopes of e-SAFE: stakeholders interested to have more information, to join our stakeholders community, and to participate to the upcoming "call for expression of interest" for virtual pilots are invited to contact us through the reported social media.

I recall that "virtual pilot" means that, inside e-SAFE, we will follow the entire renovation design process, until the preparation of a detailed design of all renovation works. The renovation of the buildings wil not be realized within e-SAFE: possible sinergies and clustering with other project are welcome.

The European Union has sponsored the development of a new friction dissipating system, for improving seismic behaviour of existing buildings. The proposed system consists of CLT-elements connected to the external beams of existing reinforced concrete building using steel profiles. Each of the steel profiles consists of two separate plates connected by a friction connection made by preloaded bolts in elongated holes. The authors carried out the experimental testing of the friction connection by estimating the corresponding hysteresis curve. A Duhem-like mechanical model, matching with the experimental results, simulates the cyclic response of the connection. The authors investigate the seismic performance of a structural archetype, a plane RC frame with CLT shear walls equipped with this sort of friction dampers. It is assessed the optimum preload condition to achieve an optimal seismic performance according to the Italian seismic scenario by the fragility assessments. A selected suite of earthquakes
is the basis of Incremental Dynamic Analysis (IDA) of the structural archetype, without and with the friction device. The optimum preload of the dissipating systems descends by optimizing the structural performance: maximizing the dissipated energy by preventing damage to the CLT panel and the reinforced concrete frame.

In earthquake-prone countries, the need for interventions aimed at improving both the seismic resistance and energy efficiency of the existing building stock is widely recognized, although the implementation of such interventions is currently limited by economic and technical barriers, as well as socio-cultural ones.

In order to overcome these barriers, a new holistic design approach to the building renovation is strongly needed, which can result in innovative and integrated retrofitting interventions able to specifically meet the current needs of cost-effectiveness, quick installation, reduced users’ disturbance and low environmental impact.

To this purpose, the use of Cross Laminated Timber (CLT) has been recently investigated as an alternative and sustainable solution to seismic strengthen the existing buildings, thanks to its high mechanical performance. In this research context, an innovative integrated (seismic-energy-architectural) renovation technology for reinforced concrete (RC) framed buildings is currently under development within the ongoing multidisciplinary Horizon 2020 innovation project, called e-SAFE (energy and Seismic AFfordable rEnovation solutions). The proposed technology consists in the application of prefabricated timber-based panels on the existing outer walls, combining structural CLT panels (called e-CLT), equipped with innovative friction dampers for seismic energy dissipation, with non-structural wooden framed panels hosting high-performing windows (called e-PANEL).

This paper illustrates a possible technical and functional application solution of this new renovation system, aimed at ensuring a correct and easy installation and operation. To this end, the proposed solution has been applied to a specific case study, i.e. a typical apartment building located in the city of Catania, in Southern Italy.

Deep renovation interventions on existing buildings remain currently unattractive due to technical, financial and cultural/social barriers. Now that the European Union 2018 Energy Performance Directive aims to “reach the long-term greenhouse gas emission goal and decarbonize the building stock”, Member States may use their long-term renovation strategies to address risks also related to fire hazards and seismic loads in addition to energy renovation. This opens a wider market for innovative approaches in retrofit of existing buildings.                                                                                                                                                                                 The current paper illustrates the primary outcomes of an ongoing multidisciplinary Horizon 2020 research project (called e-SAFE), tackling the integration of energy, seismic and architectural renovation interventions through an innovative and combinable technological solution, applicable to non-historic RC framed buildings (i.e. built after 1950) and easily adaptable to specific climatic conditions, seismicity levels and other boundary conditions. Hence, the proposed solution will contribute to the de-carbonization of the EU building stock, reducing the occurrence of natural hazards related to climate changes, and, at the same time, to the improvement of the social resilience against earthquakes and to the enhancement of buildings architectural image.                              The seismic retrofit technology consists in the external application of modular prefabricated Cross Laminated Timber (CLT) panels on the existing perimetral walls. These panels are connected to the beams of two consecutive floors by means of friction dampers and provide additional lateral stiffness and strength to the existing structure, thus reducing the storey drift demand in case of earthquake. The friction dampers cut the force transmitted by the CLT panel to the structure and dissipate energy, which further reduce the drift demand. Strength, stiffness and dissipation capacity provided by the system are controlled by modulating the thickness and the number of CLT panels, as well as the friction dampers size.                                                                                      In this research phase, friction damper prototypes have been designed in order to optimize both mechanical performance and production process. Detailed numerical models allowed to investigate the stress distribution in the dissipative connections. The results of the preliminary testing campaign will be presented and discussed in this paper, also in relation with the findings of the numerical analysis and future tests.

In Italy, as well as in other earthquake-prone countries, most buildings have been erected with-out considering the effects of seismic excitation or according to obsolete seismic design provi-sions. Furthermore, they also suffer from significant structural deficiencies because of the low mechanical characteristics or the natural decay of the materials. The seismic vulnerability of the existing building stock is a serious economic and social concern and the need for retrofit-ting or rebuilding grows as time progresses. In this framework, this study investigates a newly developed retrofit technique for buildings with RC framed structure. The intervention is realized by means of Cross-Laminated Timber (CLT) panels placed over the exterior walls and connected to the RC structure by friction dampers. The CLT panels provide the existing structure with addi-tional lateral stiffness and strength. The role of the friction dampers is twofold. On one hand they cap the internal forces of CLT panels, thus controlling the reaction forces transmitted to the exist-ing structure and avoiding the failure of CLT panels themselves. On the other, friction dampers dissipate part of the input earthquake energy. The effect of these multiple features could reduce the storey drifts demanded by the earthquake to values compatible with the structure capacity. This paper aims at sounding the impact of the proposed retrofit solution on the response of the RC framed structure to be upgraded. To this end, a one storey RC frame representative of existing RC framed structures designed considering only gravity loads is upgraded by a CLT panel and friction dampers of usual size. The impact of the retrofit intervention is investigated in terms of the achieved increase of stiffness, strength and energy dissipation capacity. The bare RC frame and the frame equipped with CLT panel and friction dampers are modelled in OpenSEES environment. Hence, the nonlinear responses of the two frames are assessed by mon-otonic and cyclic pushover analyses and the comparison between the results obtained for the bare and the upgraded frame quantifies the expected impact of the proposed retrofit intervention.

This paper aims at showing the concept, the scope and the main challenges of the four-year innovation project e-SAFE, started in October 2020 and funded by the EU in the framework of the H2020 Programme. e-SAFE aims to develop a new deep renovation system for non-historical reinforced concrete (RC) framed buildings, which combines energy efficiency and anti-seismic retrofitting actions with a series of further advantages including affordability, improved architectural image and reduced implementation time, costs and occupants’ disruption. e-SAFE will also address strategies to activate new value chains to boost the deep renovation market throughout Europe, including financial and social aspects. The paper will also present some preliminary results about the expected energy and carbon reduction ensured by the e-SAFE solutions.

This paper investigates the transient hygrothermal performance of an innovative energy and seismic renovation solution for reinforced concrete (RC) framed buildings, based on the addition of Cross-Laminated Timber (CLT) panels to the outer walls, in combination with wood-based insulation. This solution is being developed in the framework of a four-year EU-funded project called e-SAFE. The investigation relies on numerical simulations in DELPHIN 6.1, by considering combined heat and mass transfer (HAMT) due to water vapour diffusion and capillary transport. The proposed solution is tested in three different climates in Italy, to verify whether the CLT layer and the outer waterproof vapour-open membrane, inserted to protect the wood-based insulation from rain, still allow the effective drying of the vapour accumulated in liquid form in the walls, while also preventing mould formation. The results show that the increased thermal resistance of the wall assembly significantly reduces the total water content, although moderate risks of mould growth in the wooden materials may occur in coldest climates.

In the framework of the ongoing four-year EU-funded innovation project called e-SAFE (“Energy and seismic affordable renovation solutions”), several solutions for the energy and seismic deep renovation of reinforced concrete (RC) framed buildings in the European countries are going to be developed and demonstrated. These solutions address both the energy performance of the building envelope and the heating and cooling of the indoor spaces, and aim to be prefabricated, customizable, low-disruptive and sustainable in order to boost the decarbonisation of the largely inefficient European building stock. This paper presents the main features of the e-SAFE solutions and the results of a preliminary analysis to verify their effectiveness and compliance with European legislation and standards. The outcomes will be useful for the design and demonstration stage, by identifying issues that need to be tackled.

In the framework of the ongoing EU-funded innovation project called e-SAFE (energy and Seismic Affordable rEnovation solutions), several solutions for the energy and seismic deep renovation of reinforced-concrete (RC) framed buildings in the EU countries are going to be developed and demonstrated. One of these solutions makes use of cross laminated timber (CLT) panels connected to the existing RC frame through specifically designed dampers to increase the seismic and energy performances of the existing envelope.
This paper aims to preliminary assess the hygrothermal performance of such CLT panels when applied to various typical wall structures under different climate conditions in Italy through numerical simulations carried out according to the EN 13788 Standard and considering various indoor vapor production classes. Results show that the most problematic existing wall structures are uninsulated concrete walls, for which a risk of surface condensation and mold growth is predicted in all climate zones because of their low thermal resistance (U-value of 3.55 W·m-2·K-1), followed by uninsulated solid brick walls (U-value of 1.81 W·m-2·K-1). The application of CLT panels is found to not only significantly improve the thermal behaviour of the walls, but also to eliminate any surface and interstitial condensation issues in all climate zones.

This paper investigates the transient hygrothermal performance of an innovative energy and seismic renovation solution for reinforced concrete (RC) framed buildings, based on the addition of Cross-Laminated Timber (CLT) panels to the outer walls, in combination with wood-based insulation. This solution is being developed in the framework of a four-year EU-funded project called e-SAFE. The investigation relies on numerical simulations in DELPHIN 6.1, by considering combined heat and mass transfer (HAMT) due to water vapour diffusion and capillary transport. The proposed solution is tested in three different climates in Italy, to verify whether the CLT layer and the outer waterproof vapour-open membrane, inserted to protect the wood-based insulation from rain, still allow the effective drying of the vapour accumulated in liquid form in the walls, while also preventing mould formation. The results show that the increased thermal resistance of the wall assembly significantly reduces the total water content, although moderate risks of mould growth in the wooden materials may occur in coldest climates