The Renovation Wave for Europe highlighted the role of the public building stock for which Direct... more The Renovation Wave for Europe highlighted the role of the public building stock for which Directive 2012/27/EU has set an annual renewal rate of 3%, which should rise to reach the goal of decarbonization by 2050. In this paper, the energy retrofit of an educational building—at the academic level—in Southern Italy was investigated. The aim was to evaluate the incentive share, which could accelerate the energy efficiency process, to achieve a cost-effective nZEB. The results show that the highest incentive rate is required for interventions on the opaque building envelope, which are also those that allow the least energy savings. An incentive rate of about 45% for the energy efficiency of the transparent envelope is necessary to reduce the payback time by about 7 years. The efficiency of the plants and the installation of a PV system are energetically and economically convenient even without forms of economic incentive. Finally, if the building is brought to high energy standards—a p...
Abstract The necessity to predict building energy performance assumes a predominant role today. P... more Abstract The necessity to predict building energy performance assumes a predominant role today. Present regulations in energy matter introduce pressing objectives for the energy requalification of buildings. Within spring 2020, EU Member States must adopt the European Directive 2018/844, which focuses the attention on present buildings. It establishes new obligations to retrofit the existing building stock. Solutions to improve building energy performance and to achieve economic, energy, and environmental benefits become mandatory, requiring robust and reliable procedures for energy modeling and simulation. The present study will show the importance of considering a non-standard occupant profile in energy performance simulations. The investigated edifice is a typical residential building in Naples (southern part of Italy, Mediterranean climate), built during the sixties and seventies. For the energy retrofit of the building, the most common refurbishment interventions in the Neapolitan building stock will be assessed for energy, economic and emissions savings, and thus new thermal insulation and replacement of windows. Firstly, the results will be analyzed by taking into account a standard-use profile of the occupants. Secondly, the possible wrong behaviors of users will be examined, to compare an “energy-intensive” model with the standard retrofitted model. The impact on building energy demand of the following actions will be analyzed: more energy-intensive use of the electric and lighting systems, the opening of the windows during the activation hours of the heating/cooling systems, the modification of the thermostat setpoint, the deactivation of the shading systems. The study shows a considerable increase in energy demand, following the wrong behavior of the occupants, which affects the economic convenience of the refurbishment investment. The energy retrofit is economically and energetically feasible for a standard building occupation, but sometimes wrong habits can reduce the convenience, if energy-intensive behaviors occur. This work will show that, when the numerical building model of a common building refurbishment is realized and when the cost-benefits analysis is performed, the uncertainty in occupant behavior cannot be neglected.
On a European scale, the existing building stock has poor energy performance and particularly vul... more On a European scale, the existing building stock has poor energy performance and particularly vulnerable structures. Indeed, most of the existing buildings were built before the introduction of energy standards and under structural safety criteria different from those currently required. It is therefore necessary the intervention in existing buildings according to an integrated approach that contemplates both the structural safety and the energy efficiency of buildings. This study, consistently with the objectives of the European research project “Proactive synergy of integrated Efficient Technologies on buildings’ Envelopes (Pro-GET-OnE)”, proposes a retrofit intervention for a student dormitory of the National and Kapodistrian University of Athens. The scope of the evaluation is to understand how an integrated intervention, that implies a structural and energy retrofit, as well as a spatial redistribution, leads to an improvement of the Indoor Environmental Quality (IEQ). In detai...
One of the strategies of the European Green Deal is the increment of renewable integration in the... more One of the strategies of the European Green Deal is the increment of renewable integration in the civil sector and the mitigation of the impact of climate change. With a statistical and critical approach, the paper analyzes these aspects by means of a case study simulated in a cooling dominated climate. It consists of a single-family house representative of the 1980s Italian building stock. Starting from data monitored between 2015 and 2020, a weather file was built with different methodologies. The first objective was the evaluation of how the method for selecting the solar radiation influences the prevision of photovoltaic productivity. Then, a sensitivity analysis was developed, by means of modified weather files according to representative pathways defined by the Intergovernmental Panel on Climate Change Fifth Assessment Report. The results indicate that the climate changes will bring an increment of photovoltaic productivity while the heating energy need will be reduced until 4...
The Renovation Wave for Europe highlighted the role of the public building stock for which Direct... more The Renovation Wave for Europe highlighted the role of the public building stock for which Directive 2012/27/EU has set an annual renewal rate of 3%, which should rise to reach the goal of decarbonization by 2050. In this paper, the energy retrofit of an educational building—at the academic level—in Southern Italy was investigated. The aim was to evaluate the incentive share, which could accelerate the energy efficiency process, to achieve a cost-effective nZEB. The results show that the highest incentive rate is required for interventions on the opaque building envelope, which are also those that allow the least energy savings. An incentive rate of about 45% for the energy efficiency of the transparent envelope is necessary to reduce the payback time by about 7 years. The efficiency of the plants and the installation of a PV system are energetically and economically convenient even without forms of economic incentive. Finally, if the building is brought to high energy standards—a p...
Abstract The necessity to predict building energy performance assumes a predominant role today. P... more Abstract The necessity to predict building energy performance assumes a predominant role today. Present regulations in energy matter introduce pressing objectives for the energy requalification of buildings. Within spring 2020, EU Member States must adopt the European Directive 2018/844, which focuses the attention on present buildings. It establishes new obligations to retrofit the existing building stock. Solutions to improve building energy performance and to achieve economic, energy, and environmental benefits become mandatory, requiring robust and reliable procedures for energy modeling and simulation. The present study will show the importance of considering a non-standard occupant profile in energy performance simulations. The investigated edifice is a typical residential building in Naples (southern part of Italy, Mediterranean climate), built during the sixties and seventies. For the energy retrofit of the building, the most common refurbishment interventions in the Neapolitan building stock will be assessed for energy, economic and emissions savings, and thus new thermal insulation and replacement of windows. Firstly, the results will be analyzed by taking into account a standard-use profile of the occupants. Secondly, the possible wrong behaviors of users will be examined, to compare an “energy-intensive” model with the standard retrofitted model. The impact on building energy demand of the following actions will be analyzed: more energy-intensive use of the electric and lighting systems, the opening of the windows during the activation hours of the heating/cooling systems, the modification of the thermostat setpoint, the deactivation of the shading systems. The study shows a considerable increase in energy demand, following the wrong behavior of the occupants, which affects the economic convenience of the refurbishment investment. The energy retrofit is economically and energetically feasible for a standard building occupation, but sometimes wrong habits can reduce the convenience, if energy-intensive behaviors occur. This work will show that, when the numerical building model of a common building refurbishment is realized and when the cost-benefits analysis is performed, the uncertainty in occupant behavior cannot be neglected.
On a European scale, the existing building stock has poor energy performance and particularly vul... more On a European scale, the existing building stock has poor energy performance and particularly vulnerable structures. Indeed, most of the existing buildings were built before the introduction of energy standards and under structural safety criteria different from those currently required. It is therefore necessary the intervention in existing buildings according to an integrated approach that contemplates both the structural safety and the energy efficiency of buildings. This study, consistently with the objectives of the European research project “Proactive synergy of integrated Efficient Technologies on buildings’ Envelopes (Pro-GET-OnE)”, proposes a retrofit intervention for a student dormitory of the National and Kapodistrian University of Athens. The scope of the evaluation is to understand how an integrated intervention, that implies a structural and energy retrofit, as well as a spatial redistribution, leads to an improvement of the Indoor Environmental Quality (IEQ). In detai...
One of the strategies of the European Green Deal is the increment of renewable integration in the... more One of the strategies of the European Green Deal is the increment of renewable integration in the civil sector and the mitigation of the impact of climate change. With a statistical and critical approach, the paper analyzes these aspects by means of a case study simulated in a cooling dominated climate. It consists of a single-family house representative of the 1980s Italian building stock. Starting from data monitored between 2015 and 2020, a weather file was built with different methodologies. The first objective was the evaluation of how the method for selecting the solar radiation influences the prevision of photovoltaic productivity. Then, a sensitivity analysis was developed, by means of modified weather files according to representative pathways defined by the Intergovernmental Panel on Climate Change Fifth Assessment Report. The results indicate that the climate changes will bring an increment of photovoltaic productivity while the heating energy need will be reduced until 4...
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