Implementation Of Retrofit Research Articles

Embodied impacts of key materials for UK decarbonised domestic retrofit: Differences between sources of embodied carbon and embodied energy data

Low energy domestic retrofit consumes materials, such as insulation, membranes and glazing, with smaller quantities of structural timber, steel or concrete, which have associated embodied impacts from resource extraction, manufacture and end-of-life treatments. In retrofit design, coefficients for material embodied impacts vary widely between sources and can lead to different results in a life cycle energy or carbon analysis, and perhaps different material choices in retrofit implementation. This paper considers how and why results differ between sources, and whether such data is suitable for making climate-beneficial design decisions. Embodied energy and carbon coefficients for 18 key retrofit materials were obtained from two widely used LCA databases and their similarity was quantified. The data collected illustrates that 70% embodied energy and embodied carbon data is within 20%, but that 30% of data was more than 20% different. Consistency of product naming and the absence in the datasets of key retrofit materials are factors identified contributing to variation, and present real constraints in practice. Furthermore, this exercise showed that embodied impacts for the types of materials most prominent in retrofits are less-well characterised than other major construction materials, and presents another layer of uncertainty. The data showed embodied energy was more consistent between sources than embodied carbon. This raises doubts about the predominant use of embodied carbon over energy for such analyses and establishes that a focus on embodied carbon over embodied energy has less power to reduce greenhouse gas emissions than considering both metrics together. It is concluded that obtaining such data with confidence is challenging and requires expertise in LCA, and is therefore unlikely to be accessible to most retrofit designers. Datasets need to be more complete and offer higher confidence to ensure delivery of high quality and meaningful results for climate-beneficial design decisions.

ANALISIS AIR CONDITIONER PADA KOMPLEK PERUMAHAN DI KOTA DENPASAR

Green building retrofit is an approach that involves modifying or enhancing existing buildings to achieve higher standards of sustainability and energy efficiency. By conducting an energy audit first, it's possible to identify potential energy savings in the housing, as well as components that need to be upgraded to reach the desired level of sustainability. Retrofit solutions may include the use of implementation of efficient HVAC systems, energy-saving lighting, and better energy management. The aim of this research is to explore the potential improvements that can be applied through Green Building Retrofit with a focus on energy efficiency and sustainability in Jadi Pesona II Barat Housing, comparing the energy consumption conditions of houses before and after the energy audit, as well as calculating the payback period for occupants after the retrofit implementation. After the energy audit and Green Building Retrofit, daily energy usage in homes in Perumahan Jadi Pesona II Barat decreased from 47.45 kWh per day to 36.91 kWh per day. This indicates a reduction of 10.54 kWh per day or approximately 22.22% from the previous conditions, and the payback period analysis results show that almost all air conditioners show values in line with the project investment feasibility parameter, which is below 4.2 years.

Methodology for Assessing Retrofitted Hydrogen Combustion and Fuel Cell Aircraft Environmental Impacts

Hydrogen (H2) combustion and solid oxide fuel cells (SOFCs) can potentially reduce aviation-produced greenhouse gas emissions compared to kerosene propulsion. This paper outlines a methodology for evaluating performance and emission tradeoffs when retrofitting conventional kerosene-powered aircraft with lower-emission H2 combustion and SOFC hybrid alternatives. The proposed framework presents a constant-range approach for designing liquid hydrogen fuel tanks, considering insulation, sizing, center of gravity, and power constraints. A lifecycle assessment evaluates greenhouse gas emissions and contrail formation effects for carbon footprint mitigation, while a cost analysis examines retrofit implementation consequences. A Cessna Citation 560XLS+ case study shows a 5% mass decrease for H2 combustion and a 0.4% mass decrease for the SOFC hybrid, at the tradeoff of removing three passengers. The lifecycle analysis of green hydrogen in aviation reveals a significant reduction in CO2 emissions for H2 combustion and SOFC systems, except for natural-gas-produced H2 combustion, when compared to Jet-A fuel. However, this environmental benefit is contrasted by an increase in fuel cost per passenger-km for green H2 combustion and a rise for natural-gas-produced H2 SOFC compared to kerosene. The results suggest that retrofitting aircraft with alternative fuels could lower carbon emissions, noting the economic and passenger capacity tradeoffs.

Evaluating the Implementation of Energy Retrofits in Historic Buildings: A Demonstration of the Energy Conservation Potential and Lessons Learned for Upscaling

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.

Recent Innovations in Reducing Home Energy Costs and Improving Resilience for Low- and Moderate-Income Renters and Homeowners

Community Development (CD) practitioners across the western U.S. are engaging in new efforts to reduce energy costs and improve resilience for low- and moderate-income (LMI) communities and other populations that face barriers to economic participation and household financial stability. Energy costs and resilience are factors in housing stability, which impacts economic participation. New federal and state funding sources, as well as growing involvement from philanthropy and Community Reinvestment Act (CRA)-motivated investors, have prompted growth in energy cost savings and resilience (ECSR) options for LMI households. To help scale this work, CD practitioners are experimenting with partnerships—between workforce development providers and employers, mission-driven lenders and nonprofits, state government and utilities, retrofit companies and the public sector, state government and municipalities, to name a few. These partnerships have led to innovations in lending (for homeowners, renters, and landlords), technical implementation of retrofits, coordination across programs, consumer protection, workforce development, and technical assistance (TA) for CD practitioners. This brief provides descriptive findings from focus groups and interviews about ESCR-related work in the CD field and discusses takeaways for policy and practice.

Recent Innovations in Reducing Home Energy Costs and Improving Resilience for Low- and Moderate-Income Renters and Homeowners

Community Development (CD) practitioners across the western U.S. are engaging in new efforts to reduce energy costs and improve resilience for low- and moderate-income (LMI) communities and other populations that face barriers to economic participation and household financial stability. Energy costs and resilience are factors in housing stability, which impacts economic participation. New federal and state funding sources, as well as growing involvement from philanthropy and Community Reinvestment Act (CRA)-motivated investors, have prompted growth in energy cost savings and resilience (ECSR) options for LMI households. To help scale this work, CD practitioners are experimenting with partnerships—between workforce development providers and employers, mission-driven lenders and nonprofits, state government and utilities, retrofit companies and the public sector, state government and municipalities, to name a few. These partnerships have led to innovations in lending (for homeowners, renters, and landlords), technical implementation of retrofits, coordination across programs, consumer protection, workforce development, and technical assistance (TA) for CD practitioners. This brief provides descriptive findings from focus groups and interviews about ESCR-related work in the CD field and discusses takeaways for policy and practice.

Achieving Functional Recovery through Seismic Retrofit of Existing Buildings: Barriers and Opportunities

Earthquakes can cause extensive damage to buildings, with lengthy impacts in terms of community recovery. As a result, there is a growing interest in design approaches and standards for buildings that ensure postearthquake functional recovery. This paper qualitatively explores barriers and opportunities for achieving functional recovery in the retrofit of existing buildings. The study employs a set of focus groups engaging 21 participants who are experienced in the seismic retrofit of reinforced concrete buildings in the US. Qualitative analysis methods were used to analyze the collected data and to identify the key themes. The thematic analysis revealed three groups of owners and buildings: (1) those for which functional recovery-based retrofit may be achievable, including owners with long ownership time horizons, high-value contents or operations, and buildings whose functions cannot easily be relocated; (2) those for which retrofit for functional recovery is likely not needed nor practical, including buildings whose functions can be distributed to provide geographic redundancy or replaced with remote operations or a different building; and (3) buildings for which life safety retrofits, sustainability upgrades, or other renovations may improve functional recovery even if not explicitly targeted. The study also revealed significant barriers related to retrofit costs, insufficient or inadequate tools and guidelines for retrofit implementation, difficulty in communication of benefits, and a contradiction between community-scale goals and building-scale decisions. Opportunities identified to address these barriers include strategies to improve access to capital and funding, measure and communicate economic and other benefits, and develop tools and guidelines. This study is the first to rigorously explore the feasibility of achieving functional recovery for existing buildings, which make up a major part of the US building stock and are, therefore, significant impediments to postearthquake community recovery. The study suggests actions that can facilitate moving towards functional recovery objectives.

Evidence for residential building retrofitting practices using explainable AI and socio-demographic data

Extensive retrofits and effective policy measures are needed to meet the ambitious climate goals, particularly in the UK, with the EU’s oldest residential building stock. Researchers must investigate the factors influencing retrofits to enable effective and targeted policy measures. To date, however, there is a lack of holistically large-scale quantitative studies accounting for such factors. At the same time, great potential is seen in data-driven solutions and the use of explainable artificial intelligence (XAI). We address this research gap by combining supervised machine learning with XAI employing a three-stage approach: First, we consolidate datasets of Energy Performance Certificates from England and Wales from which we extract conducted retrofits, house prices, and socio-demographic information. Second, we apply an eXtreme Gradient Boosting (XGBoost) model that predicts whether a building has been retrofitted or not. Lastly, we use SHapley Additive exPlanations values (SHAP) as an XAI technique to identify the key factors and relationships that influence the implementation of retrofits. We succeed in substantiating results previously obtained in qualitative or small-scale studies and also find that retrofit-related policies already implemented in regional cases, such as the ”Better Homes for Yorkshire” initiative, can successfully achieve large-scale success through replication in other regions. Further, our results suggest the implementation of income-based CO2 taxes as a reasonable and easy-to-implement policy measure.

Tripartite Evolutionary Game Analysis of Stakeholder Decision-Making Behavior in Energy-Efficient Retrofitting of Office Buildings

Environmental degradation is significantly influenced by the construction industry. Energy-efficient retrofitting of existing office buildings has become an effective means of reducing building energy consumption. Implementation of retrofits requires the support and cooperation of stakeholders. However, existing studies on the dynamics of decision-making behavior among stakeholders are still relatively limited. This study constructed a tripartite evolutionary game model including the government, property owners, and end users, to better understand the behavioral evolution and evolutionary stabilization strategies of stakeholders. The results show that: stakeholders’ decision-making behavior has obvious mutual influence; benefits and costs are the dominant factors in stakeholders’ decision making; the effects of government supervision policies depend on the profitability of the project; and government behavior appears to be influenced by public willingness. In addition, targeted countermeasures were proposed for the development of the energy-efficiency retrofit market. This study provides a generic model that fits various contexts and can be used to inform a reference for scientific decision making by stakeholders.

Motivators and impediments to seismic retrofit implementation for wood-frame soft-story buildings: A case study in California.

Motivating property owners to mitigate seismic risks for existing buildings is a major challenge for many earthquake-prone regions. This article identifies primary factors that may affect the adoption of seismic retrofit by owners of commercial and residential buildings, assesses the influence of economic, social, regulatory, and individual factors on retrofit implementation in three California cities, and discusses potential approaches to promoting seismic retrofits. Data for three retrofit programs are utilized to create predictive models for retrofit probability. The results suggest that retrofit probability for multifamily residential buildings may increase with building height, median housing value, educational attainment, and population density in the neighborhood, but may decrease with building age, building size, land value, and housing vacancy rate in the neighborhood. The retrofit decision for commercial buildings is strongly correlated with the number of stories and rooms, land value, vacancy rate, and population density, while the retrofit decision for residential buildings is highly associated with building age, number of rooms, land value, median housing value, median contract rent, and educational attainment. Overall, promoting seismic retrofits requires careful consideration of different motivators and impediments to owner's retrofit actions for commercial and residential buildings, and for older, taller, larger buildings, which tend to be more vulnerable but are associated with higher retrofit costs. In addition, neighborhood characteristics including median housing value and vacancy rate may be strong indicators of the retrofit probability among building clusters.

Energy savings of radiative cooling paints applied to residential buildings

There is a growing need to understand the real-world utility and potential energy savings of radiative cooling (RC) materials. Here, we present a high-fidelity RC model which accounts for pertinent weather factors including: precipitable water, sky clearness, and dynamic convective heat transfer coefficients based on wind speed. We implement our RC model on a single-story residential building to study the impact of RC in all the ASHRAE climate zones in the United States using the 16 DOE recommended representative cities for each climate zone. For each city, we model two building types to explore both the retrofit implementation of RC materials on a typical building in use today, as well as future buildings integration based on the high efficiency building recommendations provided by the DOE. Our results show >7% and >12% electricity savings across the United States for the high efficiency building and typical building, respectively. Interestingly, we find the main benefit comes from the material’s ability to offset solar gains, while the heat flux from cooling the exterior surface temperature below the ambient is a secondary benefit. Furthermore, warm climates yield the greatest electricity savings of up to 22% and 46% for the high efficiency and typical building, respectively. We observed that warm climates utilize the “full effects” of RC materials as the below ambient cooling of the exterior is sufficient cooling to lower the interior below the set-point temperature, which greatly reduces the cooling energy demand.

Dynamic modeling of public and private decision‐making for hurricane risk management including insurance, acquisition, and mitigation policy

AbstractWe develop a computational framework for the stochastic and dynamic modeling of regional natural catastrophe losses with an insurance industry to support government decision‐making for hurricane risk management. The analysis captures the temporal changes in the building inventory due to the acquisition (buyouts) of high‐risk properties and the vulnerability of the building stock due to retrofit mitigation decisions. The system is comprised of a set of interacting models to (1) simulate hazard events; (2) estimate regional hurricane‐induced losses from each hazard event based on an evolving building inventory; (3) capture acquisition offer acceptance, retrofit implementation, and insurance purchase behaviors of homeowners; and (4) represent an insurance market sensitive to demand with strategically interrelated primary insurers. This framework is linked to a simulation‐optimization model to optimize decision‐making by a government entity whose objective is to minimize region‐wide hurricane losses. We examine the effect of different policies on homeowner mitigation, insurance take‐up rate, insurer profit, and solvency in a case study using data for eastern North Carolina. Our findings indicate that an approach that coordinates insurance, retrofits, and acquisition of high‐risk properties effectively reduces total (uninsured and insured) losses.

Implementing energy retrofits in existing hotel buildings using in-house teams: the decision-making process

PurposeAmong the existing buildings, hotels use as much as 50% of their total expenses on energy and offer significant opportunities for energy efficiency improvement. Yet, comparatively the level of implementation of energy retrofits (ER) in hotels appear to be low. This has been mainly attributed, inter alia, to the absence of clearly defined process for ensuring the delivery of ER and lack of proactive guidance for project teams to make right decisions. Hence, this study aims to propose an effective decision-making process, which could support the successful adoption and implementation of in-house-led ER projects in existing hotel buildings.Design/methodology/approachTwo in-depth case studies were carried out focussing on ER projects led by in-house teams in existing hotel buildings. Data was collected via 14 semi-structured interviews and was analysed through code-based content analysis.FindingsThe decision-making process for ER projects led by in-house teams was developed, which presents 39 key activities to be performed and 16 key decisions to be made. The parties responsible for these identified actions and decisions as well as the points at which each decision should be made to ensure the success of ER projects was also identified.Originality/valueA total of 21 new activities and 10 decisions relevant for in-house team led ER decision-making processes previously not found in literature were identified. It is hoped that the decision-making process developed in this study will serve as a roadmap for the effective adoption and implementation of ER in existing hotel buildings.

Understanding the decision-making process in homeowner energy retrofits

In 2020, owner-occupied housing accounted for 57% of the housing stock in the Netherlands. Homeowners are fully responsible for the implementation of energy retrofits. Moreover, the processes of energy retrofitting are complex and homeowners face problems such as finding financial support, reliable information and contractors. The complexity of implementing energy retrofits may discourage homeowners from continuing the process and achieving the expected benefits. Behavioural aspects and transaction costs (TC) are among the most important factors influencing consumer decision-making processes. Behavioural factors primarily illustrate a range of personal, contextual, and external factors that influence the decision-making process of homeowners. These include cognitive awareness and biases, attitudes and beliefs, experience and skills, homeowner characteristics, sociodemographic characteristics, property characteristics, and the behaviour of others. TC are any hidden costs that influence decision making but are not included in the direct physical costs of renovation services and products. This dissertation developed an integrated framework of behavioural factors and TC that impede the decisionmaking process for energy retrofits. Key findings include (1) the significant importance of behavioural factors and TC barriers. (2) the behavioural factors are particularly important in the early stages of energy retrofits and the TC barriers after the final decision. (3) the importance of behavioural factors and TC barriers differs according to the type of energy retrofit and non-energy retrofit. (4) Accounting for cognitive biases significantly improves the prediction of households' actual decisions about energy retrofits. This modelling is more accurate than the model that assumes households make rational decisions.

Building retrofit hurdle rates and risk aversion in energy efficiency investments

Despite extensive empirical evidence of the environmental benefits of green buildings and the increasing urgency to reduce carbon emissions in cities, there has been limited widespread adoption of energy retrofit investments in existing buildings. In this paper, we empirically model financial returns to energy retrofit investments for more than 3600 multifamily and commercial buildings in New York City, using a comprehensive database of energy audits and renovation work extracted from city records using a natural language processing algorithm. Based on auditor cost and savings estimates, the median internal rate of return for adopted energy conservation measures is 21% for multifamily buildings and 25% for office properties. Logistic regression modeling demonstrates adoption rates are higher for office buildings than multifamily, and in both cases adopter buildings tend to be larger, higher value, and less energy efficient prior to retrofit implementation. The economically significant magnitudes of returns to adopted energy conservation measures raise important questions about why many property owners choose not to adopt. As such, we discuss incentive and regulatory mechanisms that can overcome financial and informational barriers to the adoption of energy efficiency measures.

Key performance indicators for holistic evaluation of building retrofits: Systematic literature review and focus group study

Buildings are increasingly designed and constructed with state-of-the-art facilities. But without proper upkeep including timely implementation of appropriate retrofits throughout the operational stage, the facilities will not be able to perform to meet their intended purposes and the ever-rising user demands. Research on building retrofits has been widely pursued, but studies focusing on the identification of appropriate key performance indicators (KPIs) for holistic evaluation of building retrofits remain limited. To address this research gap, a mixed methods approach combining positivism and interpretivism was taken for a study. First, a four-stage literature review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method was conducted, which resulted in identification of 62 performance indicators that are applicable to evaluating building retrofits. Second, after consolidation and refinement the indicators underwent a focus group study. Grounded upon deliberation and shortlisting by the focus group experts, 19 KPIs were selected and the reasons for having those indicators excluded were revealed. The selected KPIs fall into four aspects: economic, environmental, users’ perspective, and health and safety, and their distributions by quantity are 37%, 26%, 26% and 11% respectively. Not only are these KPIs useful for evaluating the performance of building retrofits in practice for the betterment of a sustainable built environment, but the methodology of this study can also be taken in similar research to identify KPIs in other areas.

The Costs, Benefits and Stakeholder Analysis of an Irish Social Housing Deep Energy Retrofit Case Study

This paper analyses the results of a pilot deep energy retrofit (DER) implementation including the financial perspectives of the stakeholders with the aim of assisting DER policy development. The Multiple Beneficiary Analysis (MBA) provides technical and energetic details for a recent 12-unit DER social housing project and quantifies the multiple direct and indirect benefits – e.g. financial, economic and societal to enable a stakeholder (beneficiary) analysis. The analysis is apposite given the urgent need for effective policy development in order to enable the achievement of the low-energy retrofit mandated by the EU. The MBA finds that the stakeholder who benefits most (the tenant) makes no financial contribution to the higher standards and while the Central Exchequer also benefits significantly, the stakeholder who makes the upgrade decision (landlord) is financially dis-incentivised. Given the significant benefits which accrue to the Central Exchequer, there is an opportunity for strategic investment by the government to unlock the benefits of low energy dwellings. This would simultaneously realise ongoing financial benefits, “seed” the capability within industry and crucially increase the knowledge and understanding of low energy dwellings which is necessary to enable widespread adoption. The key finding is that despite potential returns of approximately twice the investment, and the urgent need to retrofit existing buildings, the required DER uptake is unlikely as the decision-makers require financial support to unleash the multiple benefits of energy efficient dwellings. A self-financing support is suggested for the case study for consideration.

Supportive governance for city-scale low carbon building retrofits: a case study from Shanghai

ABSTRACT There is significant potential for reducing energy use and emissions from buildings through energy efficiency retrofits. However, a number of barriers, including long payback periods and uncertainties around business models and technologies, restrict large scale implementation. A recent joint project, piloting green energy schemes and low-carbon investments in public and commercial buildings in the Changning district of Shanghai, China, indicated opportunities to break through these barriers. This study conducted a cost benefit analysis to investigate how an innovative combination of financial and non-financial supported retrofits, and could serve as a model for other urban areas. In total, 44 retrofit sub-projects were carried out and achieved energy savings of 30,217 tons of coal equivalent. The average payback period was 2.43 years, and with subsidies was further reduced to 1.79 years. The Changning Low Carbon Office played a critical role in coordinating and supporting the uptake of retrofit measures but non-economic factors continue to restrict investment by financial institutions and the implementation of retrofits on a larger scale. Key policy insights Public and commercial building retrofits in Shanghai are found to generate commercially acceptable payback periods while having achieved significant energy and emissions reductions. Subsidies from the city and district governments significantly reduced the payback periods of energy efficiency retrofits, but may also crowd out investment by financial institutions. The Changning Low Carbon Office has coordinated energy efficiency retrofitting efforts, provided access to information, helped to connect investment funds with project opportunities and support project management. Achieving the deeper retrofits needed to achieve China’s climate targets may require more substantial financial incentives.

APPLICATION OF GREEN RETROFIT TECHNOLOGY: A SYSTEMATIC REVIEW

Green retrofitting is a valuable approach for upgrading existing buildings towards sustainable performances. However, the lack of knowledge about the true cost effects and potential savings of green retrofits distracts building proprietors from paying those retrofits. Therefore, the current study reviewed fourteen studies available in the extant literature and identified twenty-eight different green retrofits incorporated into various buildings with their cost effects and saving potentials through a subsequent desktop study. The results indicated that the majority of green retrofits offer savings related to energy consumption, CO2 emissions, cooling load, and operating costs. Moreover, energy-saving lighting modifications are widely done in most buildings, while solar collectors, photovoltaics, and low-emission double glazing are used less often due to the long payback period and increased cost of implementation. Alternatively, the use of retrofits with lower costs and high savings, like BMS, lighting controllers, and boiler efficiency improvements, offsets the above setbacks. Furthermore, the highlighted retrofits include green roofing, bicycle parks, CO2 sensors, and air tightening retrofits, which also save energy. Rainwater harvesting absorbs carbon dioxide and runoff water, where implementing subsystem-level water meters, appliances with low flow rates, and greywater recycling save and recycle the portable water. Accordingly, the study promotes the effective implementation of green retrofits in future buildings.

Involvement of stakeholders in the adoption and implementation of energy retrofits in hotel buildings

PurposeExisting buildings encompass the largest segment of the built environment and, hence, have become a key target for energy retrofits (ER) to substantially reduce global energy usage. The success of ER projects is closely linked to the effective involvement of various stakeholders within the decision-making process. This paper aims to investigate different stakeholders and their involvement throughout the decision-making process of ER projects.Design/methodology/approachTwo successfully implemented ER projects in existing hotel buildings were selected as cases to gain novel insights into the key stakeholders to be involved along with their functions and roles in five different stages of the ER decision-making process. To collect required data, in total 11 semi-structured interviews were conducted with stakeholders involved in different stages of the decision-making process in the respective case studies. Data was analysed using code-based content analysis with the aid of NVivo computer software.FindingsAltogether, 18 stakeholders and 7 roles reflective of the nature of their involvement in the respective stages were established. Findings disclosed that the nature of the project, level of knowledge, expertise and commitment of internal staff, type of ownership of the facility and mode of financing have significant influence on involvement of different stakeholders in ER projects.Originality/valueThe findings of this study are useful in enhancing the successful adoption and implementation of ER through timely and effective involvement and integration of stakeholders.