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As long as buildings face various climate change impacts in recent decades, such as increased heat, particularly in the residential sector. Therefore, energy retrofit, and climate-adaptive designs may contribute significantly to climate change mitigation and adaptation strategies. At the same time, these strategies do not only improve the sustainability of dwellings/houses/residences but also contribute to broader goals of increasing energy efficiency, reducing environmental impact, offering economic benefits, and enhancing the community's resilience in the challenges they face impact from the effects of climate change. This study aims to examine and present the development of energy retrofitting, energy efficiency and climate-adaptive design for dwellings/ residential buildings in hot weather publications through bibliometric research. The research has been examined within the Web of Science™ Core Collection (W.O.S.) online database spanning from 2012 to November 2023 by using the "Title/Abstract/Keywords" category, and a comprehensive data visualisation has been conducted utilising the VOSviewer and CiteSpace programmes. The findings indicate the research trends in the literature and future challenges, and the results from these findings demonstrate the need for sustainable and energy-efficient buildings to preserve the environment and climate. These sustainable developments focus on improvements in energy retrofitting technologies, energy efficiency and saving targets, indoor thermal comfort, optimising passive design and minimising energy demand. This study will probably be a source to provide valuable insights for researchers, practitioners, experts, and policymakers to understand the implications of energy retrofitting and climate-adaptive design in hot arid climates. As well as it would offer theoretical and practical initiatives to be applied in this field.

According to the recent policies regarding energy use in buildings and the need of retrofit strategies, the aim of this work is to support policies concerning the installation of ground source heat exchangers in urban and historical areas, raising the awareness on the potential energy saving achievable with optimal sizing and limited impact on the urban environment. Archetypes have been developed distinguishing among existing and historic buildings, focusing on single-family terrace houses, which are the typical residential buildings in European historic centres.A methodology for the optimal sizing of ground source heat pumps, eventually considering dual-source system or air system has been developed combining simulations of a photovoltaic system to estimate the self-sufficiency and the self-consumption for five orientations of the building. Extreme results have been obtained for warm climates, with negligible heating energy demand and possibly free cooling systems rather than traditional cooling systems needed in wintertime. Penalty temperature was acceptable despite unbalanced energy demands. With proper inclination, photovoltaic systems could provide up to 40% of self-sufficiency share also in northern climates. An energy - economic analysis was carried out obtaining a variety of cases representing a general overview of the European building stock and the potential benefits achievable in terms of renewable energy share, energy savings and economic investments needed to be extended to simulations at urban scale.

This paper investigates the possibilities and challenges of using mass timber as a sustainable alternative for retrofitting existing buildings in Canada. To create the knowledge foundation on which to devise a holistic framework tailored to the specific characteristics of Canada's built environment, a detailed analysis of the types, geographical distribution, structural, and energy features of the local building stock is first presented. Then, previous strategies for enhancing and upgrading existing buildings with engineered timber are reviewed, classified, and evaluated. Finally, to explore economic and environmental implications, a detailed assessment of available life-cycle cost–benefit analysis approaches is conducted alongside their adaptation to Canada's building context. The findings of this paper can inform policymakers, builders, and designers in developing more sustainable building retrofit practices, design, and regulations, in line with Canada's efforts toward net zero emissions. [ABSTRACT FROM AUTHOR]

According to the recent policies regarding energy use in buildings and the need of retrofit strategies, the aim of this work is to support policies concerning the installation of ground source heat exchangers in urban and historical areas, raising the awareness on the potential energy saving achievable with optimal sizing and limited impact on the urban environment. Archetypes have been developed distinguishing among existing and historic buildings, focusing on single-family terrace houses, which are the typical residential buildings in European historic centres. A methodology for the optimal sizing of ground source heat pumps, eventually considering dual-source system or air system has been developed combining simulations of a photovoltaic system to estimate the self-sufficiency and the self-consumption for five orientations of the building. Extreme results have been obtained for warm climates, with negligible heating energy demand and possibly free cooling systems rather than traditional cooling systems needed in wintertime. Penalty temperature was acceptable despite unbalanced energy demands. With proper inclination, photovoltaic systems could provide up to 40% of self-sufficiency share also in northern climates. An energy - economic analysis was carried out obtaining a variety of cases representing a general overview of the European building stock and the potential benefits achievable in terms of renewable energy share, energy savings and economic investments needed to be extended to simulations at urban scale. [ABSTRACT FROM AUTHOR]

Urban building energy model (UBEM) is a powerful tool to simulate performance and evaluate efficiency of upgrades for a group of buildings under the urban context. However, the larger the scale/number of buildings, more parameters must be collected to create energy models that cover each individual building, causing more uncertainties. To reveal this, this study created a UBEM for the mixed modern and historic buildings at a campus in China. The calibrated set of UBEMs with the modeled results meeting the 20% error range, were then used to evaluate uncertainties of energy-savings of four building energy retrofit (BER) measures. The first measure, BER 1, was to preserve the historic values of buildings; BER 2 to meet green building design standard; BER 3 to achieve 20% more savings than BER 2; and BER 4 to utilize renewable photovoltaic energy. For BER 1, BER 2, and BER 3, the energy savings of buildings of different ages varied within 10%–44%. For BER 4, the energy savings of buildings varied within 49%–505%, respectively, where the reason for higher than 100% is energy production is much higher than energy demand. Similar results can be concluded for building functions, for BER 1, BER 2, and BER 3, the energy-saving potentials varied within 6%– 45%, while 97%–492% to BER 4. This study can provide an important and significant reference to apply UBEM in evaluating energy-efficient retrofits as well as other energy-related studies that consider uncertainties.

Research on retrofit scenarios for the energy efficiency of historical buildings is growing. Despite their potential to improve the energy consumption of a building, retrofit scenarios for indoor thermal environments and the thermal comfort of historical buildings has not been sufficiently studied. Therefore, in this study, indoor airflow, heat distribution, and thermal comfort levels of indoor residents were predicted using computational fluid dynamics (CFD) modeling of historic buildings based on measured values. Although the heating was turned on in the meeting room in winter, heat loss caused by low thermal performance, airtightness, and inflow of cold air caused local thermal discomfort. Individuals seated near the windows had a temperature difference of up to 2.6 °C between the head and ankle levels. Heat loss was identified from the exterior walls and windows, with air infiltration significantly affecting indoor thermal comfort. The airtightness of the window frames of historic buildings was low, thus necessitating related improvement in heat and energy retrofit scenarios. This study propose a suitable approach to resolve this problem.

A large share of the reinforced concrete (RC) building stock in Mediterranean countries faces a dual challenge of seismic vulnerability and energy inefficiency, calling for urgent renovation efforts. While energy upgrades have been the focus of previous renovation policies, recent research highlights the critical need for integrated retrofitting solutions that address both structural integrity and energy performance. Multi-criteria decision-making (MCDM) approaches are a promising tool for optimizing the combined choice of these integrated interventions, considering various decision variables (DVs) of economic, social, environmental, and technical nature. To understand the impact of climate and seismic hazard conditions on multi-criteria-based retrofitting assessment, a case-study RC school building is selected and assumed to be located in three distinct climate conditions, cold, mild, and warm, and three seismic hazard levels, low, medium and high. Moreover, given the complexity and challenges of quantifying seismic performance metrics for practitioners, an available simplified (practice-oriented) approach is compared herein with a more thorough research-based one for quantifying the seismic performance of RC buildings within the MCDM framework. Both approaches are applied to the case-study building, considering twelve possible combinations of energy and seismic interventions. The accuracy of the practice-oriented approach and its impact on the retrofitting rankings is evaluated, emphasizing the importance of accessible and efficient evaluation methods in facilitating informed decision-making for building renovation. [ABSTRACT FROM AUTHOR]

In light of the growing demand for sustainability in the construction sector and real estate market, the European Community (EC) has recently begun incentivizing renovations of private and public European buildings. This aligns with the EC's aim to reduce harmful emissions by 55% by 2030 compared to 1990 levels, and to achieve complete decarbonization of buildings, i.e., zero harmful emissions in this sector, by 2050. Given this framework, this study aims to verify the financial viability associated with the construction of "green" buildings, as well as the associated monetary benefits related to the efficient nature of these buildings and the resulting reduction in energy consumption. Lastly, an investigation is conducted to determine the economic feasibility of energy retrofit initiatives on existing building assets by comparing the required costs to retrofit against the potential increase in market value of a retrofitted residential unit. Along with assessing the undisputed environmental advantages for the community and all building users, this research aims to assess the financial and economic feasibility of sustainable construction initiatives, providing insight into how best to pursue the EC's aims. [ABSTRACT FROM AUTHOR]

The environmental and economic evaluation of energy renovation in buildings plays a crucial role in achieving sustainability goals and the decarbonization of the built environment. This paper presents a case study of a student house in Athens, Greece, to assess the environmental and economic impacts of energy renovation and seismic reinforcement with a steel exoskeleton. This study utilizes a comprehensive approach that combines life cycle assessment (LCA) and life cycle costing (LCC) methodologies using One Click LCA. The LCA assesses the environmental impacts associated with energy consumption and greenhouse gas emissions, while the LCC evaluates the economic aspects, both analyses being conducted for a lifespan of 25 years from now. The results provide an evaluation of what would happen in terms of greenhouse emissions and costs in two scenarios: with and without interventions. ProGETonE strategy results in an environmental impact with a GWP of 26.78 kgCO2eq/m2y with a reduction of 30% of the pre-renovation state. Economically, the actualized energy use costs for 25 years are 50% less in the post-renovation state, but the high construction costs make the strategy seem inconvenient. In this context, it is important to consider the non-economic benefits of seismic reinforcement, such as enhanced safety and the potential lives saved, which are critical in high seismic zones. These advantages complement the strategy's environmental and energy use impacts, underscoring the holistic value of integrated seismic and energy retrofitting approaches like ProGETonE. The study underscores the importance of LCA and LCC analyses when evaluating the feasibility of renovation projects and of an evidence-based decision-making process for policymakers, building owners, and stakeholders for energy-efficient retrofitting. [ABSTRACT FROM AUTHOR]

Renovating buildings with cultural heritage significance is an important step toward achieving sustainability in our cities. The benefits are not only energy-related but also encompass social aspects that make these renovations a high apriority. The present work investigates the renovation process of a cultural heritage building in the Municipality of Trento in Italy, specifically focusing on achieving energy savings and renewable energy integration by implementing various renovation actions. These renovation actions include improvements to the building envelope, such as roof insulation and window replacements. Additionally, the renovation actions for active systems involve the installation of a ground-source heat pump for heating/cooling coupled with a borehole thermal energy storage system, which is an innovative technology for the renovation of cultural heritage buildings. The electrical systems of the building are upgraded through the addition of standard rooftop photovoltaics, innovative building-integrated photovoltaics (shingles), and the installation of an LED lighting system. The baseline and the renovation scenarios are studied using the dynamic simulation tool INTEMA.building, written in the programming language Modelica. This tool simulates both the building envelope and the energy systems with a high level of detail, using advanced control systems and adjustable time steps. According to the simulation analysis, the primary energy demand is reduced by 30.49%, the final energy demand by 36.74%, and the net electricity demand by 8.72%. Results from this study can be useful to interested stakeholders (e.g., building owners, architects, construction companies, public agents, and urban planners) dealing with the renovation of cultural heritage and protected buildings. Also, the results can be exploited for estimating energy savings by applying advanced renovation strategies for cultural heritage buildings. [ABSTRACT FROM AUTHOR]

The use of Building Information Modelling (BIM) for Building Energy Simulation (BES) is challenged by inadequate data integration and unreliable data and geometry conversion. Despite recent efforts to address critical interoperability issues, the effective exchange of data between the two digital environments remains a non-truly fulfilled promise of the digital transformation agenda for the industry. To contribute to the broader community effort in mitigating this deficiency, the present article proposes an alternative method for securing an improved BIM to BES workflow for existing and heritage buildings. The proposed method suggests an alternative way for integrating environmental analysis data to the Heritage BIM model, as well as an easy to develop visual programming process for missing data recovery, through auxiliary exchange operations. The article also presents lessons learned for the geometrical conversion of BIM elements with non-standard and irregular attributes, evaluated through the energy retrofit application of a colonial heritage building. The proposed method demonstrates how visual programming tools and common data exchange formats can supplementary assist existing practises to deal with major interoperability obstacles. The overall findings contribute to current efforts in the field, for the establishment of good practices of using Heritage BIM for energy retrofit architectural interventions. [ABSTRACT FROM AUTHOR]

The building operation sector in China represents 22% of the national energy consumption and 22% of the carbon emission, of which urban residential buildings accounted for 24% in 2019. Such figures for the housing sector are projected to increase sharply in the near future, while China aims to peak CO2 emissions by 2030 and reach neutrality before 2060. To reduce the impacts of the urban housing sector and address the energy use and waste generated by large-scale demolition and reconstruction, the central government started promoting the energy retrofit of urban residential buildings, raising such policies to the national strategic level. Jiangsu Province is one of the most urbanised, with a rapid growth in the energy consumption of residential buildings. The Multi-Danyuan and Single-Danyuan Apartment built in 1980–1999 are the most representative residential types in its urban areas. While still adequate functionally, they were designed and built to low energy standards and show significant potential for energy retrofit. Nonetheless, their current performance and energy-saving potential are under-researched, while more detailed and reliable data would be critical to support retrofit design and policy making. This study investigates and characterises the typical use and energy performance of the two building types. Additionally, seven measures and six retrofit scenarios were identified based on the optimal energy reductions and regulations from selected countries. The simulations indicate that, without intervention, the energy consumption of the typical urban residential buildings can reach 122 kWh/m2 under the typical high-energy user scenario. By selecting a set of effective energy-saving measures, the operational energy use for heating and cooling can be reduced by up to 52.4%. Current local standards prove cost-efficient, although less effective in reducing energy use compared to international best practices, indicating potential improvements to the contribution of building retrofit towards achieving the national carbon reduction goals. [ABSTRACT FROM AUTHOR]

The article presents a design experiment conducted within the research PNRR VITALITY based on the issues of sustainability and the quality of living spaces. Considering the innovation opportunities expressed by the energy transition, also achieved through nature-based regenerative solutions, aimed at reducing consumption and CO2 emissions, the methodology leads to the conceptualisation of the multiscalar spatial device Green Room: a volumetric decrement action associated with vegetative infiltration applied to significant parts of buildings and open spaces in three sample areas of the Adriatic-Mediterranean region. Starting from morphological, typological, and climatic data and managing computational simulation processes, the experiment aims to update design tools at the architectural and urban scale, establishing a relationship between indoor and outdoor spaces to achieve benefits for the environment and people’s well-being. Article info Received: 18/03/2024; Revised: 20/04/2024; Accepted: 27/04/2024

This study presents an in-depth analysis of 69 case studies focusing on the energy retrofit of historic buildings, uncovering challenges, best practices, and lessons learned to balance energy efficiency improvements with heritage preservation. The findings highlight several challenges encountered during renovations, such as complex heritage evaluations, restrictions on alterations, coordination issues with authorities, technical limitations, higher investment costs, and knowledge gaps. On the other hand, identifying factors promoting renovation, including demonstrating energy savings while respecting heritage, early collaboration between planners and authorities, and quantifying investments, could incentivize owners and authorities. The limitations of a still-limited sample size, occasional incomplete data, and potential sample bias call for cautious interpretation of the presented analysis. Despite these, the study provides valuable insights into successful projects, emphasizing the need for scalability, knowledge transfer from innovative policies, and targeted policy-making for successful replication. The study concludes with a call for further development of the HiBERatlas (Historic Building Energy Retrofit atlas), an extensive resource for historic building renovation, expanding its database, collaborating with agencies, and tailoring guidance for stakeholders to foster energy retrofits in heritage buildings.

Energy poverty (EP) has emerged as a significant and multifaceted social challenge, both in Europe and globally, in recent years. Given the constraints of limited public resources, it is imperative that policies addressing EP focus on the most socially vulnerable households. To this end, effective policies necessitate a thorough understanding of the key characteristics defining households affected by this phenomenon. This research aims to contribute to the identification of energy-poor households by examining both established and novel EP indicators, utilizing the Athens urban area as a case study. The study employs the official EP indicator utilized in Greece, alongside three newly developed indicators. These indicators constitute essential components in the formulation of multivariate binary logistic regression models. The models incorporate predictors derived from existing government databases, encompassing household and building characteristics. From a policy perspective, this research introduces novel approaches for addressing EP, as the models and two of the newly introduced indicators demonstrate promising results in identifying energy-poor households. Importantly, this identification can be achieved without the need for primary questionnaire surveys or the compilation of complex information. [ABSTRACT FROM AUTHOR]

This study presents an in-depth analysis of 69 case studies focusing on the energy retrofit of historic buildings, uncovering challenges, best practices, and lessons learned to balance energy efficiency improvements with heritage preservation. The findings highlight several challenges encountered during renovations, such as complex heritage evaluations, restrictions on alterations, coordination issues with authorities, technical limitations, higher investment costs, and knowledge gaps. On the other hand, identifying factors promoting renovation, including demonstrating energy savings while respecting heritage, early collaboration between planners and authorities, and quantifying investments, could incentivize owners and authorities. The limitations of a still-limited sample size, occasional incomplete data, and potential sample bias call for cautious interpretation of the presented analysis. Despite these, the study provides valuable insights into successful projects, emphasizing the need for scalability, knowledge transfer from innovative policies, and targeted policy-making for successful replication. The study concludes with a call for further development of the HiBERatlas (Historic Building Energy Retrofit atlas), an extensive resource for historic building renovation, expanding its database, collaborating with agencies, and tailoring guidance for stakeholders to foster energy retrofits in heritage buildings. [ABSTRACT FROM AUTHOR]

Energy retrofits have, so far, been studied from the perspective of economic benefits that undertaking energy retrofit brings. They have also been of interest in the pursuit of reducing carbon emissions. However, few have studied the perception of health co-benefits of energy retrofits. Therefore, this paper seeks to shed light on how the residents' perception of their health affects their decision to undertake an energetic retrofit. The focus of this article is to determine how residents perceive their health and their willingness to undertake energy retrofits to improve their health in the municipality of Barcelona. The methods used were in-depth interviews with experts and face-to-face and surveys conducted online. The results were analysed using descriptive, segmental, and unconditional logistic regression. We also analysed if awareness of the health co-benefits of retrofits corresponded with the respondent's housing conditions, socio-demographics, and willingness to energy retrofit their homes. A total of 127 participants were included, of which 6.3% listed health co-benefit improvements as an influencing factor in undertaking an energy retrofit. The survey findings show that the less educated households are less aware of the health co-benefits of energy retrofits. These findings reveal the need to re-evaluate the current energy and housing policies. [ABSTRACT FROM AUTHOR]

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In order to plan and manage low-carbon investments in wide real estate assets, in this research, a strategic approach is developed to act on building stocks as a whole, with the aim of overcoming the single-building perspective and identifying the energy retrofit level leading to the maximum possible benefit. It is shown how artificial intelligence (AI) and optimization computing are essential to the creation of the decision-making process. In fact, energy improvement consists of an optimization problem in which conflicting objectives and constraints are balanced, and several techniques are integrated to achieve a unified result, including machine learning, economics, building energy simulation, computer programming, optimization, and risk analysis. This target is achieved by means of Artificial Neural Networks (ANNs) for energy consumption assessment, an Analytic Hierarchy Process for energy retrofit compatibility assessment, and an evolutionary optimization algorithm for the achievement of the optimal configuration of intervention on the stock, maximizing the energy and economic performance of the investment. The proposed procedure is validated on the case study of a building asset located in Northern Italy. Since the developed model relies on AI-based algorithms, it has a consequent limitation: the developed ANNs can work only for the building types, occupation profiles and climatic areas that were used in the training phase. In further development of this research, the aim will be to expand the generalization properties of the forecasting tool. [ABSTRACT FROM AUTHOR]

In order to meet climate goals, it will be necessary to significantly reduce the greenhouse gases emitted by homes. A key factor in the US is to reduce the on-site combustion of fossil fuels for heating end-uses and to replace this with use of electric heat pump technologies connected to a low-carbon grid. The replacement of natural gas furnaces with electric heat pumps is a key home decarbonization strategy. However, the potential for space heating electrification to reduce greenhouse gas emissions depends on the carbon dioxide equivalent (CO2e) content of the electricity used by the heat pump. This varies considerably depending on the source of electricity, with large state to state variability. Furthermore, household energy costs are likely to be impacted by the electrification of space heating, because retail energy prices for both natural gas and electricity in each state vary by factors of seven and four, respectively. Contractors, energy programs, government and building code officials, as well as consumers need clear indications of the likely CO2e and energy cost impacts of proposed electrification projects, because these will affect decarbonization choices and rationales around scaled heating electrification. Government and utility programs also need to be aware of the likely outcomes of any supported/incentivized measures. In this paper, we investigate these effects by looking at new metrics to analyze the change in CO2e emitted and the cost to meet home heating loads when switching from a natural gas furnace to a heat pump for the contiguous 48 states of the mainland US.

This work aims to characterize how home energy upgrade projects and programs in the US have evolved over the past decade. It also identifies what changes are needed to drive expansion of the US energy retrofit market in such a way that addresses carbon emissions from buildings, improves resilience and upgrades the housing stock. This review focuses on whole-home energy upgrades, targeting deep energy retrofit savings of >30%. The topics we cover include trends in home electrification, US and European home energy upgrade programs, energy upgrade measure costs, business economics, and health effects. Key changes in project design noted in this review include: (1) the electrification of dwellings with rapidly improving heat pump systems and low-cost solar photovoltaic technology; and (2) a shift away from high-cost building envelope strategies and towards more traditional home performance/weatherization envelope upgrades. Promising program design strategies covered include: (1) end-use electrification programs; (2) novel financing approaches; (3) the use of carbon-based program and project metrics; and (4) “one-stop shop” programs. Based on the existing market barriers, we suggest that the industry should adopt new project performance metrics. Additionally, market drivers are needed to spur widespread energy upgrades in the US housing stock. Costs must be reduced, and projects designed to appeal to homeowners and contractors.

In many middle- and high-income countries, existing buildings will occupy the majority of building areas by 2050 and measures are needed to upgrade the mentioned buildings for a sustainable transition. This research proposes a method to mitigate the energy consumption of existing educational buildings using four energy efficiency measures (EEMs). The proposed method divides simulations into two main parts: simulations with and without using heating, ventilating, and air conditioning (HVAC) systems. Four passive EEMs are used, including window replacement, proposed shading devices, new insulations, and installing a new partition wall for the entrance part of the building. This research uses a simulation-based method to examine the effect of each EEM on the energy consumption of the building using DesignBuilder software. The steps of data collection and modeling in this research include collecting raw data related to the physical characteristics of the building experimentally and creating a basic model. Afterwards, simulation scenarios were defined based on the proposed method, and several simulations were carried out to examine the impact of each EEM on the energy performance of the building. Two environmental parameters of the simulation process, including indoor air temperature (IAT) and relative humidity (RH), were used. The measures reduced the heating and cooling demands in the building by 80.14 % and 15.70 %, respectively. Moreover, the results indicated that the total energy consumption of the building were reduced by 10.44 % after retrofitting measures.

The architecture of the 20th century stands as an imperative realm of experimentation. Inside it, the architecture of the Modern Movement emerged from 1900 to 1940, with shapes, features, and materials completely different from pre-industrial buildings, rejecting traditional construction practices, techniques, and materials. Its key design concepts include (i) the "Form Follows Function" principle establishing a strict relationship between building aesthetics and function, favoring minimalism, balanced composition, and visible materials; (ii) the creation of comfortable and healthy buildings with natural light and ventilation through windows, biophilia, and spacious rooms; and (iii) advancements in engineering enabling novel design possibilities (e.g., metal-framed curtain walls, complex windows) and mass-produced materials (e.g., glass, steel, reinforced concrete, plywood, Masonite, and cast iron). These criteria directly influence energy efficiency and human comfort. Otherwise, technical problems have emerged due to inadequate comprehension of the long-time performance of these experimentations, leading to deterioration and aging. This research provides a complete overview of the energy and climatic performances of Modern Architecture, discussing the building physics implications of the key design principles through several case studies. [ABSTRACT FROM AUTHOR]

The research presents approaches to the complex refurbishment of multi-family buildings constructed during the mass construction period in Serbia. These buildings comprise a quarter of Serbia's housing stock, are characterized by high energy consumption for heating, and have major spatial and organizational deficiencies: small apartments, outdated and inflexible spatial organization, and the absence of elevators. The subject of the research is the application of the methodology of complex and integrated refurbishment by adding volume to existing multi-family buildings with the goal of achieving higher energy efficiency while remodeling and modernizing residential units and improving vertical building communications. The research presents a comparative analysis of the energy performance and spatial organization of the existing building and three variants of building improvement: Case 1 (without volumetric additions), Case 2 (with volumetric additions—relocating vertical communications), and Case 3 (with volumetric additions—expanding usable living space). Based on the Knaufterm simulations, the energy savings for heating energy consumption compared to the existing state are 81% in Case 1, 89% in Case 2, and 87% in Case 3. Based on predefined parameters of spatial comfort, a comparative analysis of spatial comfort in residential units was conducted for all three improvement variants. [ABSTRACT FROM AUTHOR]

The environmental and economic evaluation of energy renovation in buildings plays a crucial role in achieving sustainability goals and the decarbonization of the built environment. This paper presents a case study of a student house in Athens, Greece, to assess the environmental and economic impacts of energy renovation and seismic reinforcement with a steel exoskeleton. This study utilizes a comprehensive approach that combines life cycle assessment (LCA) and life cycle costing (LCC) methodologies using One Click LCA. The LCA assesses the environmental impacts associated with energy consumption and greenhouse gas emissions, while the LCC evaluates the economic aspects, both analyses being conducted for a lifespan of 25 years from now. The results provide an evaluation of what would happen in terms of greenhouse emissions and costs in two scenarios: with and without interventions. ProGETonE strategy results in an environmental impact with a GWP of 26.78 kgCO2eq/m2y with a reduction of 30% of the pre-renovation state. Economically, the actualized energy use costs for 25 years are 50% less in the post-renovation state, but the high construction costs make the strategy seem inconvenient. In this context, it is important to consider the non-economic benefits of seismic reinforcement, such as enhanced safety and the potential lives saved, which are critical in high seismic zones. These advantages complement the strategy’s environmental and energy use impacts, underscoring the holistic value of integrated seismic and energy retrofitting approaches like ProGETonE. The study underscores the importance of LCA and LCC analyses when evaluating the feasibility of renovation projects and of an evidence-based decision-making process for policymakers, building owners, and stakeholders for energy-efficient retrofitting.

The building operation sector in China represents 22% of the national energy consumption and 22% of the carbon emission, of which urban residential buildings accounted for 24% in 2019. Such figures for the housing sector are projected to increase sharply in the near future, while China aims to peak CO2 emissions by 2030 and reach neutrality before 2060. To reduce the impacts of the urban housing sector and address the energy use and waste generated by large-scale demolition and reconstruction, the central government started promoting the energy retrofit of urban residential buildings, raising such policies to the national strategic level. Jiangsu Province is one of the most urbanised, with a rapid growth in the energy consumption of residential buildings. The Multi-Danyuan and Single-Danyuan Apartment built in 1980–1999 are the most representative residential types in its urban areas. While still adequate functionally, they were designed and built to low energy standards and show significant potential for energy retrofit. Nonetheless, their current performance and energy-saving potential are under-researched, while more detailed and reliable data would be critical to support retrofit design and policy making. This study investigates and characterises the typical use and energy performance of the two building types. Additionally, seven measures and six retrofit scenarios were identified based on the optimal energy reductions and regulations from selected countries. The simulations indicate that, without intervention, the energy consumption of the typical urban residential buildings can reach 122 kWh/m2 under the typical high-energy user scenario. By selecting a set of effective energy-saving measures, the operational energy use for heating and cooling can be reduced by up to 52.4%. Current local standards prove cost-efficient, although less effective in reducing energy use compared to international best practices, indicating potential improvements to the contribution of building retrofit towards achieving the national carbon reduction goals.

Heritage architecture, which considers the local climate, building materials, and construction methods, can contribute to the energy efficiency and sustainability of buildings. Retrofitting strategies can be applied to existing buildings to improve their energy performance while maintaining or enhancing their thermal comfort. This study involved an analysis of the indoor environment status at the Yonsei University Stimson Hall (completed in 1920), a building on the former Yonhee College (now Yonsei University). The analysis included temperature and humidity measurements over a one-year period in four rooms with different usage schedules and occupant types. It was found that the number of occupants and the usage schedule influenced the temperature distribution in the rooms. In addition, the effects of the retrofitting strategies on the building energy consumption were investigated. It was verified that the improvement in windows and the application of roof-type photovoltaic systems resulted in annual energy savings of up to 90.46% compared with reference buildings. In conclusion, the findings demonstrate the influence of variables such as usage schedule, occupant type, and season on the indoor climate, as well as the potential benefits and drawbacks of retrofitting strategies on energy consumption and thermal comfort.

Building energy requalification in Italy and Europe has been much discussed in recent years due to the high percentage of existing buildings with poor energy performance. In this context, it is useful to obtain a user-friendly and fast tool to predict the thermal energy demand (TED) for space conditioning and the related primary energy consumption (PEC) as a function of climatic stress. In this study, the SLABE methodology (simulation-based large-scale uncertainty/sensitivity analysis of building energy performance) is used to simulate representative Italian buildings, varying parameters such as geometry, envelope and HVAC (heating, ventilating and space conditioning) systems. MATLAB® in combination with EnergyPlus is used to analyze 200 buildings belonging to two structural types (multi-family buildings and apartment blocks) built in 1961–1975. Nine scenarios (as-built scenarios and eight retrofit ones) are investigated in 63 climatic locations. A regression analysis shows that the classical HDDs (heating degree days) approach cannot give an accurate prediction of TED because solar radiation is not accounted for. Thus, new climatic indices are developed alongside solar radiation, including the heating stress index (HSI), the cooling stress index (CSI) and the yearly climatic stress index (YCSI). The purpose of our work is to obtain climatic stress curves for the prediction of TED and PEC. Testing of this novel approach is performed by comparison with another building energy simulation tool, showing a low discrepancy, i.e., the coefficient of variation of the root mean square error is between 12% and 28%, which confirms certain reliability of the approach here proposed. [ABSTRACT FROM AUTHOR]

The current global context, marked by crises such as climate change, the pandemic, and the depletion of fossil fuel resources, underscores the urgent need to minimize waste. Cogeneration technology, which enables simultaneous production of electricity and thermal energy from electricity generation waste, offers a promising solution to enhance energy efficiency. Its widespread adoption, particularly in the European Union, where several cogeneration systems are in place, demonstrates its growing popularity. Italy alone has 1865 high-efficiency cogeneration units, contributing significantly to total cogeneration energy generation. Micro-cogeneration, specifically, has attracted attention for its potential to reduce energy waste and environmental impact. This study focuses on assessing the technical and financial feasibility of a micro-cogeneration plant using natural gas-fuelled internal combustion engines, considering different scenarios of plant operating strategies in order to optimize energy production, minimize waste, and mitigate environmental footprints associated with conventional methods. Additionally, it provides valuable guidance for policymakers, industry stakeholders, and decision-makers invested in sustainable energy solutions. By advancing micro-cogeneration technology, this study aims to promote a more sustainable and environmentally conscious approach to energy production. The methodology applied is based on the development of a numerical model via RETScreen Expert 8 and it was calibrated with one-year energy bills. The study was performed by focusing on the analysis of the annual energy savings, greenhouse gas emission savings, tonnes of oil equivalents savings, and financial parameters such as Net Present Value (NPV), Internal Rate of Return (IRR), Profitability Index (PI) and Payback time (PBT). The results show, using a micro-cogeneration system in a big complex of buildings, that the financial parameters can continually increase with the plant's capacity with the electrical load following, but with a loss of the recovered heat from the cogenerator because it may reach values that are not necessary for the users. When the thermal load variation is much more significant than the electrical load variation, it will be useful to design the plant to follow the thermal load variation which allows the full utilization of the thermal and energy production from the plant without any waste energy and choosing a system capacity that can optimize the energy, emissions and financial aspects. [ABSTRACT FROM AUTHOR]

Because of the social importance of hospitals, characterized by energy-intensive users, large-scale refurbishment projects for these types of buildings are required. With the aim of helping researchers and designers, this paper proposes a multistage methodological approach for the optimization of retrofit designs based on energy, environmental, and economic indicators. Some guidelines are also highlighted thanks to the results obtained from a case study of a private hospital in Naples (Southern Italy, Mediterranean climate) located in a constrained landscape area. The first step consists of the calibration of a simulation energy model defined via in situ investigations, direct surveys and monitoring of energy loads and indoor quality. Then, the model is used to verify the effectiveness of several efficiency measures regarding the building envelope, the active energy systems, and the energy conversion from renewables in order to minimize the energy demand with acceptable economic profitability. This case study demonstrates that electricity demand can be reduced by up to 48% with an investment of around EUR 720,030.00; the payback time without national incentives is 10 years, but it can be halved with appropriate financial support. [ABSTRACT FROM AUTHOR]

As the urgency to mitigate climate change intensifies, the achievement of zero carbon targets in the built environment has become a critical objective. Building retrofitting plays a vital role in reducing energy consumption and carbon emissions in existing buildings. This paper presents an approach that combines Building Information Modeling (BIM) with multiple domains to strive for zero carbon targets in building retrofit projects. The proposed approach is based on a dynamic multi-parameter analysis that integrates indoor comfort, energy savings, CO2eq reduction, and the social cost of carbon while considering investment costs. Renewable energy technologies, such as photovoltaic panels and solar thermal systems, are emphasized to achieve the desired zero-carbon outcomes. Real-time monitoring mechanisms enable continuous performance evaluation and adaptive retrofit strategies for further energy savings. This approach is validated through a case study of an existing thermal bath building, known as "Terme Lucane", located in southern Italy. The results of the study demonstrate significant reductions in energy consumption and carbon emissions, highlighting the potential of the proposed approach to achieve zero carbon targets through the integration of multi-data BIM implementation. These findings offer a promising pathway for building retrofit projects aiming for zero carbon targets through multi-data BIM modeling. [ABSTRACT FROM AUTHOR]

Buildings are responsible for significant energy consumption and carbon emissions. Green buildings, which incorporate advanced building technologies, offer a solution to reducing energy use. However, high costs associated with green building development present a barrier to widespread adoption. Retrofit projects, involving remodeling, renovation, and redevelopment of existing buildings, offer a viable solution. While prior studies have examined the cost analysis of green and non-green buildings, there is a lack of evidence comparing new and retrofit projects. This study aims to address this gap by providing empirical evidence for the cost decomposition and benefits of new and retrofit projects. Data on energy use, building technology, and costs from 235 certified green homes in the United States were collected, and cost benefits were evaluated. Results show that retrofit projects cost, on average, $1270.5/m2 ($118.0/ft2), which is 30% less than new projects. Land acquisition and development account for 35% of retrofit costs, six times greater than new projects. Excluding land costs, retrofit projects cost, on average, $733.88/m2 ($68.2/ft2), 49% less than new projects. Retrofit projects use similar building technologies as new projects and produce larger energy savings. The cost-benefit values generated by retrofit projects are 86% greater than new projects when considering land costs and 142% greater without considering land costs. These findings contribute to cost management for complex building projects and energy policy for sustainable development. Retrofitting offers great potential to promote the green building movement and suggests effective subsidy programs as a public policy implication. [ABSTRACT FROM AUTHOR]

The Architecture, Engineering and Construction sector requires an intense innovation process to reduce costs, intervention times, and improve energy performance. This is particularly true to increase the rate of deep renovations of the existing European building stock and therefore support the EU’s 2050 decarbonisation targets. In this scenario, prefabrication can be considered a game-changer for the construction industry: on the one hand, it enables the adoption of an industrial mindset to the design, manufacturing, and installation of façade components, with the related advantages in terms of time, cost and quality; on the other, it allows for the customisation of components thanks to digital, BIM-based design and fabrication tools. However, its adoption in retrofit operations is still limited due, among other factors, to a lack of practical experience and a limited number of actual demonstration cases. This paper introduces an operative guideline to support a more widespread use of prefabricated thermal insulation components for the energy retrofit of existing buildings in the framework of a BIMenabled design and construction process. The guideline highlights the information flow and the role of each actor at every stage of the design and delivery process. The proposed guideline is finally tested through its application to a case study to show the feasibility of the process and the advantages deriving from the adoption of an industrialised approach to façade retrofit in terms of faster installation times.