Energy Efficient Renovation Research Articles

Stop procrastinating, start renovating! Exploring the decision-making process for household energy efficiency renovations

A tricky contributor to the “energy efficiency gap” is homeowners who fail to finalize a planned Energy Efficiency Renovation (EER) project, even after having received an offer from a contractor. However, there is a lack of evidence on drivers and barriers of homeowners' EER in the final stage of the decision process, including the role of the energy consultation and homeowners' perceptions of barriers and impediments that can potentially lead to procrastination, that is, to the postponement of tasks. This study contributes to filling this gap based on a survey of 609 Danish homeowners in the final stage of an EER decision-making processes. Through a comparative analysis of adopters and non-adopters, we find that procrastination is a common reason for non-adoption. First, we identify potential predictors that differ between adopters and non-adopters. Next, these variables are included in a structural equation path model (SEM) to estimate their direct and indirect effects on EER adoption. We find that homeowners' final implementation of EER decisions is complex and far from a simple weighing of monetary costs and benefits. Psychological factors such as expected hassle and interpersonal aspects of the consultation, as well as perceived difficulties and impediments, specifically related to how easy an EER offer is to understand and ultimately accept, are identified as core antecedents of EER adoption or procrastination. Implications for interventions to reduce procrastination in EER decisions are discussed, including financial support measures and interventions designed to make it easier for homeowners to implement their EER decisions.

Multi-objective decision optimization design for building energy-saving retrofitting design based on improved grasshopper optimization algorithm

With the national emphasis on building energy efficiency planning, energy efficiency optimization in existing buildings requires renovation measures based on multi-objective factors. In order to get the optimal solution in the multi-objective decision-making of renovation, the study proposes a class of improved grasshopper optimization algorithms. The process employs a systematic methodology to identify an optimal energy renovation method, taking into account the specific characteristics of the building environment. It then classifies and formulates the energy reduction substitution items for building renovation, and finally, it synchronizes the cost of the renovation project as a measure for decision-making. The elite inverse strategy approach enhances the grasshopper optimization algorithm to facilitate the multi-objective decision-making process associated with building renovation measures. The results showed that the improved grasshopper optimization algorithm could achieve a decision accuracy of 98.8% for the test samples, which was 5.5% higher than the accuracy of the particle swarm optimization algorithm. Repeated run tests of the research algorithm for multi-objective decision making yielded a mean decision fitness value of 2.34×104 and a data extreme value of 0.38×104. Compared to other algorithms improved grasshopper optimization algorithm converged in a lower range of fitness values, which indicated that the algorithm worked well for multi-objective optimization and the model repeatability was good. The research algorithm was used to decide the energy efficient renovation planning of the building and the power consumption of the renovated power supply system was reduced by 23.7%-49.6%. This indicates that the renovated building has better energy efficiency and can provide a reliable technical direction for decision-making optimization of building energy efficiency renovation.

The Potential of AI in Information Provision in Energy-Efficient Renovations: A Narrative Review of Literature

<p>Energy-efficient renovation (EER) is a complex process essential for reducing emissions in the built environment. This research identifies homeowners as the main decision-makers, whereas intermediaries and social interactions between peers are highly influential in home renovations. It investigates information and communication barriers encountered during the initial phases of EERs. The study reviews AI tools developed within the EERs domain to assess their capabilities in overcoming these barriers and identifies areas needing improvement. This research examines stakeholders, barriers, and the AI tools in the literature for EERs. The discussion compares the functionalities of these tools against stakeholder needs and the challenges they face. Findings show that tools often overlook methodologies in human–computer interaction and the potential of textual and visual AI methods. Digital tool development also lacks insights from social science and user feedback, potentially limiting the practical impact of these innovations. This article contributes to the EERs literature by proposing an AI-supported framework and outlining potential research areas for future exploration, particularly improving tool effectiveness and stakeholder engagement to scale up the EER practice.</p>

Exploring occupant behaviors and interactions in buildings with energy-efficient renovations: A hybrid virtual-physical experimental approach

Energy-efficient renovations significantly affect how people use buildings, and these occupant behaviors, in turn, influence the effectiveness of building renovations. Exploring interactions between occupants and renovations is essential for implementing building energy-efficient renovation. However, physical experiments for this purpose require extensive setups in the laboratory to observe occupant behaviors under various renovations. Immersive virtual environment (IVE) experiments as an emerging method still need to adequately incorporate thermal stimuli, essential for studying occupant behaviors, building renovations, and related interactions.Therefore, this study proposes a novel approach that integrates virtual and physical environments in experiments to explore occupant behaviors and their interactions with building renovations. The interactive and immersive capabilities of IVE experiments allow for effective simulation of various renovations and occupant behaviors. By incorporating thermal stimuli from physical experiments, this approach overcomes previous limitations in studying thermal-related occupant behaviors. In a field study, an office building looking for renovation is used to explore occupant behaviors and their interactions with building renovations. It is found that energy-efficient renovation impacts personal heater use and door opening behaviors, but not clothing behaviors; such changes in heater use subsequently impact the energy performance of building renovation. In further analysis, obvious correlations are revealed between personal heater use and renovation scenarios, thermal perception, and times of day. The proposed approach is validated as a novel method to engage the occupants in achieving occupant-centric building energy-efficient transitions.

INCENTIVIZING LANDLORD ENGAGEMENT IN A CLEAN ENERGY TRANSITION IN NOVA SCOTIA, CANADA: A CASE STUDY OF ENERGIZE BRIDGEWATER

ABSTRACT Split incentives, in which the costs and benefits of energy efficiency upgrades are unevenly felt between landlords and tenants, are a powerful barrier that prevents retrofits from taking place. The problem is clearly playing out across the low-income, and inefficient homes of Bridgewater, Nova Scotia, Canada, where greenhouse emissions are high, and a large proportion of residents are burdened by energy poverty. To help solve the problem and facilitate home energy efficiency renovations, a project called Energize Bridgewater was developed. Guided by 10 semi-structured interviews with Energize Bridgewater team members (n = 4) and property managers (n = 6), we present a case study which sought to contextualize and better understand how Energize Bridgewater may incentivize owners of rental houses to participate in this clean energy transition. Our results focus on three main findings: i) the reality of the split incentive problem in Bridgewater; ii) barriers to landlord engagement; and iii) reactions to proposed programming. We close this paper with a discussion of the theoretical and practical implications of our work, including a set of recommendations for Energize Bridgewater and similar projects facing the split incentive problem while working toward a clean and cost-effective energy transition.

Integrated home renovation services as a means to boost energy renovations for homeowner associations: A comparative analysis of service providers’ business models

Across the European Union (EU), approximately 46% of the population resides in apartment buildings. A majority of these buildings are in need of energy renovation and are managed by Homeowner associations (HOAs). HOAs face distinct challenges in renovating their buildings. Integrated home renovation services (IHRS) have emerged as a potential solution to accelerate highly energy-efficient renovations for HOAs. The question arises: How do current integrated home renovation service providers facilitate energy renovations for homeowner associations, overcoming the prevailing barriers to uptake? This paper explores the current state of IHRS providers operating in four European regions with a focus on the Netherlands and Flanders. The study offers insights into the dynamics of their business models, strategies, and ways forward. The methods employed involve a combination of qualitative approaches. Fourteen business models of IHRS providers in the Netherlands, Belgium, France, and Austria were analysed, to define their strategies within the regional context. The results reveal that while public entities prioritize broad societal challenges, private models focus on operational efficiency and financial sustainability. Public-private partnerships offer a hybrid approach, blending strengths but requiring precise governance to align diverse interests and achieve comprehensive, sustainable outcomes. The findings can inform policymakers, practitioners, and researchers in developing effective and targeted IHRS initiatives in the EU.

Basics of energy-efficiency of renovation of existing office buildings and restoration of listed buildings

The article highlights the basics of energy-efficiency of renovation of existing office buildings, adaptive reuse of buildings for the office function and energy restoration of listed buildings. The advantages of renovation over the new construction in terms of sustainability and reduction of energy consumption were considered. Three different approaches to energy renovation were studied, depending on the location of the buildings and their listing status: existing buildings located outside the historical areas of the cities; existing buildings located in the historical areas of cities; and listed buildings. Principles and methods of energy-efficient renovation of existing office buildings and energy restoration of listed buildings were reviewed. As for the listed buildings, during the modernization or restoration aiming the increase of energy efficiency - the material component of the buildings, which determines its authenticity, should be preserved as much as possible. Regarding the renovation of existing not listed buildings but located in the historical areas - the height, scale, plastic solution, character, finishing materials, etc. must be preserved. It has to be done in order to preserve the identity and the character of the historically inherited environment of a certain area of the city. A list of passive and active design strategies for energy consumption reduction of office buildings during renovation and energy-efficient restoration was provided. Including following passive strategies: facades and roof insulation; low infiltration values; optimization of the glazing ratio; optimal selection of glazing types; use of solar shading devices; use of daylight; passive heating due to solar radiation in winter; use of natural ventilation; integration of greenery into the building; use of internal structures of the building with high heat capacity; use of "double" glass facades, etc. The limitations that reduce the possibilities of energy modernization of listed buildings were considered. Ukrainian and foreign case-studies of renovation, adaptive reuse and restoration were researched and critically analyzed.

Main Principles and Solutions for Acceleration of Energy Efficient Renovation in Latvia

The European Renovation Wave aims to at least double the annual energy renovation rate by 2030, especially promoting deep renovation. In order to achieve this goal, EU member states need to overcome the existing obstacles in the whole chain of the building renovation process by using certain policy measures and finance instruments. According to the Ministry of Economics of Latvia, the current necessity is to renovate around 26 thousand multi-apartment buildings. Therefore, not only the problem of the lack of additional financing should be solved but also the pace of implementation should be significantly increased. This study starts with an overview of the main obstacles of the building renovation in Latvia and gives an insight into the main challenges in the achievement of the goal. The study includes the review of existing support programmes and financing schemes, designed to improve the energy efficiency of multi-apartment buildings in Latvia. Moreover, the study analyses the existing support mechanisms in Latvia, and reviews different policy measures for regulatory requirements, fiscal and economic incentives and information campaigns in Europe. In addition, the study proposes an assessment of the availability of financial support for the low-income households, and analyses energy poverty solving tools. As a result, the study defines basic principles and examines the solutions for energy efficient renovation in Latvia – including tax incentives, regulatory framework, development of financial schemes and models for acceleration of building renovation. The solutions have been evaluated considering country specific economic, technical, and social aspects, and defined as a set of recommendations for decision makers.

Deep energy efficiency renovation of Germany’s residential buildings: is this as economically viable as Germany’s policymakers and popular promoters often claim?

Germany needs to steeply increase the rate of deep energy-efficiency renovation of its old buildings, to meet climate goals. The government has long maintained that deep renovation to a specified “minimum” energy efficiency standard is economically viable: that the costs are paid back, through energy savings, over the technical lifetime of the energy-efficiency measures. Many private and public organisations support and promulgate this view. It accords with a stream of academic literature which suggests that the under-adoption of energy efficiency measures is a paradox indicating market failures and economically irrational behaviour by property owners. This paper offers cost–benefit analyses of 44 case study scenarios to test whether deep renovation in Germany pays back in monetary terms. These include both specific buildings and Germany-wide averages of classes of buildings. It uses current construction, finance and energy costs, and takes account of inflation, discount rates and opportunity costs. None of the scenarios are economically viable in monetary terms, and the average payback after 25 years is around 22.5%. Sensitivity analyses suggest payback would only be achieved using improbable parameter values. Energy-efficiency renovation is necessary but promoting it needs to take account of these realities.

How photovoltaics make energy refurbishment more affordable in apartment buildings

The costs of energy efficiency renovation of Germany’s postwar apartment buildings have sharply increased since pre-covid years, as have interest rates and hence the costs of servicing loans that finance these renovations. Despite increases in energy costs, it has become virtually impossible to recoup energy-efficiency renovation costs through energy cost savings, with many projects bringing substantial losses. The common method of third parties offering rotating finance to ease the initial costs, and being repaid after short payback periods, therefore no longer works. On the other hand, rooftop photovoltaics have decreased sharply in price, and continue to do so. This study explores the economics of installing photovoltaics, with or without heat pumps, along with energy-efficiency renovation, based on two typical case study apartment buildings in North Rhine-Westphalia. Using fine-grained energy flow modelling and net-present value cost-benefit analysis, it finds that energy-efficiency renovation brings losses of over 80% but that these can be substantially reduced by the gains from rooftop PV, especially when a heat pump is included. The larger the PV system, the larger the gains, but roof size limits this. The study recommends that shared rooftop PV systems be promoted as the norm with comprehensive energy-efficiency renovation in Germany.

Impact of Retrofitting Strategies for Sustainability of Building

In response to the urgent need for sustainability, the modernization of existing buildings has become a key strategy to improve the environmental protection of the built environment. The purpose of this study is to examine the multifaceted impact of modernization strategies on enhancing sustainability through a comprehensive synthesis of the existing literature. Combining empirical findings and theoretical insights, this study aims to provide a comprehensive understanding of the environmental, economic and social impacts associated with modernization. The study begins by identifying the general goals and motivations that drive modernization efforts, including the need to reduce carbon emissions, optimize resource use and promote resilience in the face of climate change. Next, the study explores the various renovation methods and technologies available, from energy-efficient renovations to passive design strategies and renewable energy integration. Through a systematic review of empirical studies and case studies, the effectiveness of these measures in mitigating environmental impacts, improving user comfort and achieving long-term cost savings is identified. In addition, the research seeks to unravel the complex interaction between modernization strategies and broader socio-economic dynamics, including equity, affordability and community engagement. Critically assessing the impact of the proliferation of renovation projects, the research aims to identify potential barriers to equal access and participation, thus promoting inclusive and inclusive approaches to sustainable building development. In conclusion, this study contributes to the evolving debate on sustainable building practices by providing nuanced insights into the opportunities and challenges of renovation strategies. By synthesizing existing knowledge and highlighting critical gaps in understanding, research aims to inform policy. actors, actors and stakeholders in the field of the built environment, facilitating evidence-based decision-making and promoting the transition to a more sustainable built environment.

Workflow for Window Composition Detection to Aid Energy-Efficient Renovation in Low-Income Housing in Korea

Enhancing the efficiency of windows is important for improving the energy efficiency of buildings. The Korean government has performed numerous building renovation projects to reduce greenhouse gas emissions and mitigate energy poverty. To reduce the costs and manpower requirements of conventional field surveys, this study presents a deep-learning model to examine the insulation performance of windows using photographs taken in low-income housing. A smartphone application using crowdsourcing was developed for data collection. The insulation performance of windows was determined based on U-value, derived considering the frame-material type, number of panes, and area of windows. An image-labeling tool was designed to identify and annotate window components within photographs. Furthermore, software utilizing open-source computer vision was developed to estimate the window area. After training on a dataset with ResNet and EfficientNet, an accuracy of approximately 80% was achieved. Thus, this study introduces a novel workflow to evaluate the insulation performance of windows, which can support the energy-efficient renovation of low-income housing.

Modern requirements for energy-efficient renovation of historical buildings

Мodern urban development trends includes the importance of taking historical buildings into account when implementing sustainable development strategies. Energetic modernization of historical buildings has both economic and social benefits. Buildings of historical importance often do not correspond to the requirements of modern directives, but the use of certain technical means and architectural practices allows to achieve a significant increase in energy potential. Energy-efficient renovation of historic buildings is an important component in the formation of future smart cities, since historic buildings themselves connect society with the heritage of the past and represent local and historical features of the city and its inhabitants. At the same time, the relevance of the problem is related to the insufficient systematization of data and information resources along with the constant development of tools for diagnosis and assessment of potential changes when working with historical buildings according to their characteristics. The main modern requirements for energy-efficient renovation of historical buildings, as well as the stages of analysis of the characteristics of historical buildings, and the further formation of the renovation strategy and the selection of appropriate methods and measures are considered. Considered limitations and features of the renovation of historic buildings (general engineering limitations due to the historical context, specific characteristics of a specific building, design limitations).

Low carbon emission renovation of historical residential buildings

The urgency of renovating residential buildings in heritage conservation areas while addressing carbon emission reduction and energy performance has become a concern in the context of climate change. European directives stress the importance of enhancing existing buildings to achieve climate neutrality by 2050. An approximately 100-year-old wooden apartment building in the heritage conservation area in Võru, Estonia, was designed as a nearly zero-energy building (nZEB). This study examined the impact of different renovation scenarios, considering both embodied and operational carbon emissions. During the study, the technical requirements of the National Heritage Board were developed in several aspects. The results of this study indicate that it is possible to renovate buildings in heritage conservation areas and achieve great energy performance. In addition to improving energy performance, it is possible to make the restoration of a significantly damaged exterior with intermediate repairs more cost-effective for the owner. Deep renovation of a historical wooden building decreases its carbon footprint as it leads to more energy-efficient renovation solutions. This is because operational emissions dominate over embodied emissions in a cold climate. From an environmental perspective, it is more feasible to renovate historically valuable buildings more deeply than it is to upgrade the external appearance of buildings. Renovation work to achieve an nZEB building should include insulating the thermal envelope while restoring the historical appearance and preserving the original building profile. In conclusion, this study offers a comprehensive analysis of various scenarios, including carbon footprint, energy performance, and cost optimality, related to different renovation strategies for buildings located in heritage conservation areas. There is a need to align heritage board technical requirements with the environmental perspective. Given that major renovation is more cost-effective and better at preserving the exterior appearance compared to staged renovation, the former should be preferred to ensure the owner's willingness to pay.

Looking beyond energy efficiency and the role of financial literacy in experiencing fuel poverty: Evidence from Irish homeowners

Previous research has established that an effective way to fight fuel poverty is to increase levels of energy efficiency in residential buildings. A different strand of research has shown that the adoption of energy efficiency measures is more likely if people have high financial literacy. We combine these two strands of research by conducting a new survey among Irish homeowners and directly analysing the association between financial literacy and fuel poverty. Given that energy efficiency renovation is not always economically viable, we also investigate the drivers of other strategies to cope with high energy prices, such as switching the household’s energy supplier and using direct debit payments. While our results confirm that high energy efficiency is associated with lower fuel poverty, at least for some measures, we find no evidence of a link between people’s financial literacy and the energy efficiency level of their homes. We find only weak evidence of a direct negative association between financial literacy and fuel poverty. We investigate several related aspects of fuel poverty using our survey data. We find that low overall household income is strongly associated with a higher prevalence of subjective measures of fuel poverty, a lower likelihood to engage in some energy cost mitigation strategies, and the likelihood to see administrative challenges as insurmountable barriers in the retrofit process. Policy measures aiming to reduce fuel poverty or increase energy efficiency or financial literacy should therefore all focus on low-income households.

Understanding transaction costs of energy efficiency renovations in the Swedish residential sector

The residential sector has a large potential to reduce its energy use. Improving the energy performance of buildings is one way to realise this potential. For single-family buildings, improving the energy efficiency by energy renovations can produce a net financial gain. However, there are unaccounted barriers that act as impediments for house-owners to undertake energy efficiency measures. This study postulates that transaction costs are such a barrier. Transaction costs are defined as the cost of making an economic exchange on a market in addition to the market price. The purpose is to empirically estimate the magnitude of the transactions costs and its determinants for energy efficiency measures in the residential sector. Specifically, the transaction costs for heat insulation and energy-saving windows in Swedish single-family buildings are assessed. The analysis is based on a unique dataset, constructed from a web-based survey. The results indicate that transaction costs for energy efficiency measures are considerable. The average transaction cost to make additional heat insulation is SEK 18,046 (EUR 1,510) and SEK 21,106 (EUR 1,766) to install energy-saving windows. The determinants of the transaction costs are cognitive limitations, social connectedness, asset specificity and previous experiences. Therefore, to reduce the transaction costs, the complexity of energy efficiency measures must be addressed, potential opportunistic behaviour must be reduced, and financial options expanded.

A Holonic Construction Management System for the Efficient Implementation of Building Energy Renovation Actions

In the architecture, engineering and construction (AEC) industry, many efforts have provided remarkable contributions to construction planning and control processes during work execution. Nevertheless, frequent coordination issues among stakeholders and difficulties in dealing with unexpected events can be explained by the complexity featuring the construction sector. Several approaches to deal with this issue were investigated in the manufacturing area, among which this paper looks at the holonic approach as one of the most promising strategies. This study first analyzes the more fragmented and dynamic nature of the construction industry as compared with the manufacturing one. Secondly, it suggests developing a process-based holonic construction management system based on building information modeling (BIM) and a conceptual architecture for manufacturing control called Product Resource Order Staff Architecture (PROSA). The process-based paradigm ensures exploiting the benefits of BIM towards the development of sustainable and efficient regeneration methods of the built environment. Subsequently, a first management system prototype was developed and tested for the purpose of renovation works management. For the first time, results from an actual implementation of PROSA were applied to a real construction site, and its feasibility was assessed using the data on the field. Key performance indicators (KPIs) evaluated during the onsite demonstration confirmed a good performance of PROSA and the presented holonic approach, which contributed to the overall success of the energy efficient refurbishment project.

Greenhouse Gas Payback Time of Different HVAC Systems in the Renovation of Nordic District-Heated Multifamily Buildings Considering Future Energy Production Scenarios

The European Union (EU) has implemented several policies to enhance energy efficiency. Among these policies is the objective of achieving energy-efficient renovations in at least 3% of EU buildings annually. The primary aim of this study was to offer a precise environmental comparison among four similar district-heated multifamily buildings that have undergone identical energy efficiency measures. The key distinguishing factor among them lies in the HVAC systems installed. The chosen systems were as follows: (1) exhaust ventilation with air pressure control; (2) mechanical ventilation with heat recovery; (3) exhaust ventilation with an exhaust air heat pump; and (4) exhaust ventilation with an exhaust air heat pump with a Photovoltaic (PV) panel. This study involved a life cycle assessment that relied on actual material data from the housing company and energy consumption measurements. This study covered a period of 50 years for thorough analysis. A sensitivity analysis was also conducted to account for various future scenarios of energy production. The findings revealed that the building with an exhaust air heat pump exhibited the lowest greenhouse gas emissions and the shortest carbon payback period (GBPT), needing only around 7 years. In contrast, the building with exhaust ventilation without heat recovery showed the highest emissions and the longest carbon payback period (GBPT), requiring approximately 11 years. Notably, the results were significantly influenced by future scenarios of energy production, emphasizing the crucial role of emission factors in determining the environmental performance of distinct renovation scenarios.

Application research of deep learning-based BIM Technology in Intelligent Construction

Abstract With the increasing importance of energy-efficient renovations in architecture, the pressing issue of how to enhance the effectiveness of such renovations through advanced technology has come to the forefront. This article affirms the significance of building information modeling (BIM) technology in energy consumption renovations. It introduces a BIM-based building energy monitoring system, which not only provides comprehensive and effective static information for energy consumption analysis but also offers real-time visualization of energy consumption status for daily management. By collecting all necessary data for energy management and storing it in the cloud, this system greatly facilitates data analysis. Moreover, the article proposes a short-term electricity load forecasting method for community buildings based on empirical mode decomposition (EMD)-gated recurrent unit (GRU). The EMD-GRU method proposed in this article exhibits superior accuracy compared to other methods, with a mean absolute percentage error value of 14.43%. By considering factors such as historical load, weather, and date, this method accurately predicts short-term electricity loads for communities. This research provides a robust framework for improving energy management in buildings through advanced technologies, ultimately leading to more effective energy-saving renovations and optimizations.

Comparison of solar district heating and renovation of buildings as measures for decarbonization of heat supply in rural areas

In this study two different decarbonization strategies for rural heat supply are compared on the example of 180 buildings located in a small village in Germany with about 860 inhabitants and typically mainly old buildings, partly in half-timbered construction. The comparison shows that erection of a solar district heating system with solar fraction of about 67 % leads to similar heating costs as an energy efficient renovation followed by installation of decentralized air source heat pumps for most of the buildings. Both concepts aim to achieve a heat supply that is free from the local use of fossil fuels. While the solar district heating system can probably be realized within a few years and therefore achieves the full CO2 savings promptly, this would take decades for the implementation of energy efficient renovation and heat pumps due to low renovation rate. Reaching climate-neutrality for the heat supply could thus be accelerated significantly by the construction of a solar district heating system. Moreover, the two decarbonization approaches do not appear to be fundamentally mutually exclusive: subsequent steady renovation of connected buildings will either increase solar share in heat supply or enable connection of new consumers at similar solar coverage rate. However, it should be also noted that with solar district heating alone, not always the same thermal comfort as with reinforced building renovation is achieved.