The Experts below are selected from a list of 13854 Experts worldwide ranked by ideXlab platform
Jay Yang - One of the best experts on this subject based on the ideXlab platform.
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Analysis of interrelationships between critical waste factors in office Building Retrofit projects using interpretive structural modelling
International Journal of Construction Management, 2014Co-Authors: Jay YangAbstract:The number of office Building Retrofit projects is increasing. These projects are characterized by processes that have a close relationship with waste generation and therefore demand a high level of waste management. In a preliminary study reported separately, we identified seven critical factors of on-site waste generation in office Building Retrofit projects. Through semi-structured interviews and interpretive structural modelling method, this research further investigates the interrelationships among these critical waste factors, identifies each factor’s level of influence on waste generation and proposes effective solutions for waste minimization. ‘Organizational commitment’ was identified as the fundamental issue for waste generation in the ISM system. Factors related to plan, design and construction processes were found to be located in the middle levels of the ISM model but still had significant impacts on the system as a whole. Based on the interview findings and ISM analysis results, some practic...
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Critical factors for waste management in office Building Retrofit projects in Australia
Resources Conservation and Recycling, 2014Co-Authors: Jay YangAbstract:Abstract Office Building Retrofit is a sector being highlighted in Australia because of the mature office Building market characterised by a large proportion of ageing properties. The increasing number of office Building Retrofit projects strengthens the need for waste management. Retrofit projects possess unique characteristics in comparison to traditional demolition and new builds such as partial operation of Buildings, constrained site spaces and limited access to as-build information. Waste management activities in Retrofit projects can be influenced by issues that are different from traditional construction and demolition projects. However, previous research on Building Retrofit projects has not provided an understanding of the critical issues affecting waste management. This research identifies the critical factors which influence the management of waste in office Building Retrofit projects through a literature study and a questionnaire survey to industry practitioners. Statistical analysis on a range of potential waste issues reveals the critical factors, as agreed upon by survey respondents in consideration of their different professional responsibilities and work natures. The factors are grouped into five dimensions, comprising industry culture, organisational support and incentive, existing Building information, design, and project delivery process. The discussions of the dimensions indicate that the waste management factors of office Building Retrofit projects are further intensified compared to those for general demolition and construction because Retrofit projects involve existing Buildings which are partially operating with constrained work space and limited Building information. Recommendations for improving waste management in office Building Retrofit projects are generalised such as waste planning, auditing and assessment in the planning and designing stage, collaboration and coordination of various stakeholders and different specialists, optimised Building surveying and BIM technologies for waste analysis, and new design strategies for waste prevention.
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The engagement of small to medium enterprises for managing waste in Building Retrofit projects
Science & Engineering Faculty, 2013Co-Authors: Jay YangAbstract:The market of Building Retrofits is increasingly more intensified as existing Buildings are aging. The Building Retrofit projects involve existing Buildings which impose constraints on stakeholders throughout the project process. They are also risky, complex, less predictable and difficult to be well planned with on-site waste becoming one of the critical issues. Small and Medium Enterprises (SMEs) carry out most of the work in Retrofit projects as subcontractors, but they often do not have adequate resources to deal with the specific technical challenges and project risks related to waste. This paper first discusses the requirements of waste management in Building Retrofit projects considering specific project characteristics and work natures, and highlights the importance of involving SMEs in waste planning and management through an appropriate way. By utilizing semi-structured interviews, this research develops a process model for SMEs to be applied in waste management. A collaboration scenario is also developed for collaborative waste planning and management by SMEs as subcontractors and large companies as main contractors. Findings from the paper will promote coordination of project delivery and waste management in Building Retrofit projects, and improve the involvement and performance of SMEs in dealing with waste problems.
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New strategies of managing waste in office Building Retrofit projects
2012Co-Authors: Jay YangAbstract:Retrofit projects are different from newly-built projects in many respects. A Retrofit project involves an existing Building, which imposes constraints on the owners, designers, operators and constructors throughout the project process. Retrofit projects are risky, complex, less predictable and difficult to be well planned, which need greater coordination. For office Building Retrofit project, further restrictions will apply as these Buildings often locate in CBD areas and most have to remain operational during the progression of project work. Issues such as site space, material storage and handling, noise and dust, need to be considered and well addressed. In this context, waste management is even more challenging with small spaces for waste handling, uncertainties in waste control, and impact of waste management activities on project delivery and Building occupants. Current literatures on waste management in office Building Retrofit projects focus on increasing waste recovery rate based on project planning, monitoring and stakeholders’ collaboration. However, previous research has not produced knowledge of understanding the particular Retrofit processes and their impact on waste generation and management. This paper discusses the interim results of a continuing research on new strategies for waste management in office Building Retrofit projects. Firstly based on the literature review, it summarizes the unique characteristics of office Building Retrofit projects and their influence on waste management. An assumption on waste management strategies is formed. Semi-structured interviews were conducted towards industry practitioners and findings are then presented in the paper. The assumption of the research was validated in the interviews from the opinions and experiences of the respondents. Finally the research develops a process model for waste management in office Building Retrofit projects. It introduces two different waste management strategies. For the dismantling phase, waste is generated fast along with the work progress, so integrated planning for project delivery and waste generation is needed in order to organize prompt handling and treatment. For the fit-out phase, the work is similar as new construction. Factors which are particularly linked to generating waste on site need to be controlled and monitored. Continuing research in this space will help improve the practice of waste management in office Building Retrofit projects. The new strategies will help promote the practicality of project waste planning and management and stakeholders’ capability of coordinating waste management and project delivery.
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Planning for SME's proactive waste management in office Building Retrofit projects
2011Co-Authors: Jay YangAbstract:Office Building Retrofit projects face many challenges for on-site waste management. While the projects themselves have the potential for a significant level of reuse and recycling from decon-struction and demolition, their unique characteristics often prohibit direct application of existing waste management systems, which are typically based on managing waste generated through new material application in new build projects. Moreover, current waste management plans include no stimuli to involve Small and Medium Enterprises (SMEs) for on-site waste management. As SMEs carry out the majority of on-site work as subcontractors, their active involvements will result in more proactive approaches to waste management and enhance project delivery. This paper discusses the interim results of a continuing research aimed at engaging SMEs in the planning processes of waste management through the collaboration between subcontractors and main contractors of Retrofitting projects. It introduces a conceptual model for SMEs to proactively plan and manage on-site waste generation for both deconstruction and construction stages, before traditional waste management plans by the main contractor come into place. The model also suggests a collaboration process between SMEs as subcontractors and large companies as the main contractor to improve the involvement and performance of SMEs in waste management of office Building Retrofit projects.
Andre Omer Desjarlais - One of the best experts on this subject based on the ideXlab platform.
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Whole Building Retrofit using vacuum insulation panels and energy performance analysis
Energy and Buildings, 2019Co-Authors: Kaushik Biswas, Tapan Patel, S. Shrestha, Douglas Smith, Andre Omer DesjarlaisAbstract:Abstract Vacuum insulation panels (VIPs), due to their high thermal performance, provide an attractive alternative to traditional Building insulation materials, especially as an option for Retrofitting old, poorly insulated Buildings. This article describes the complete Retrofit of all exterior walls of a single-story Building in a cold climate using VIPs. A recently-developed low-cost VIP, called modified atmosphere insulation (MAI), was used in this study. Two Buildings of near-identical construction were studied, with one remaining unaltered and serving as the baseline while the other served as the Retrofit Building. The VIPs or MAI panels proved to be a feasible and durable option for Retrofitting Building envelopes. Thermal performance of both Buildings was analyzed using in-situ temperature and heat flow sensors. Numerical models of the two Buildings were created, benchmarked using experimental data and used for predictions of annual energy savings due to the addition of MAI panels to the exterior walls. The models predicted significant reduction in the annual heating energy consumption in the Retrofitted Building compared to the baseline Building.
Godfried Augenbroe - One of the best experts on this subject based on the ideXlab platform.
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a cost effective Building Retrofit decision making model example of china s temperate and mixed climate zones
Journal of Cleaner Production, 2021Co-Authors: Md Uzzal Hossain, Martin Skitmore, Godfried AugenbroeAbstract:Sustainable Building Retrofitting has attracted serious research attention in recent years as it can significantly reduce energy consumption and thus help achieve energy reduction targets set by governments around the world. In this paper, a sustainable Retrofit decision-making model is developed to uncover the optimal set of Retrofit solutions according to local climatic conditions, Building features, and Retrofit costs. Net present value (NPV), a common method for analyzing the feasibility of a Building Retrofit solution, is used to determine the optimal Retrofit solution of existing high-rise residential Buildings in a temperate zone and hot summer-cold winter zone, involving prototypical 1990s apartments of 116 and 53 m2 floor areas respectively. This reveals that the lighting system, wall insulation, and upgraded window glazing are essential optimal Retrofit measures for the temperate zone, whereas the heating system and shading devices are also essential for the hot summer-cold winter zone. The results indicate that the optimal NPV can be obtained by pursuing a 40% energy saving, as it can result in energy saving of up to 50 kWh/m2/year and 95 kWh/m2/year at an average Retrofit cost of approximately USD 1.30 and 3.20 m2/year in the temperate and hot summer-cold winter zones respectively. The sensitivities associated with the most influential optimal NPV and energy savings input parameters are critically analyzed; these can be used by decision-makers to determine the risks and uncertainties related to various cost-effective Retrofit measures. The model can help in devising the most suitable sustainable Retrofit measures for existing Buildings commensurate with the energy reduction targets of policy and decision-makers in the two climate zones. It is also amenable to being adapted for other climatic zones to identify the most appropriate sustainable Building Retrofit for particular local climatic conditions and Building characteristics.
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A cost-effective Building Retrofit decision-making model – Example of China’s temperate and mixed climate zones
Journal of Cleaner Production, 2021Co-Authors: Uzzal Hossain, Martin Skitmore, Godfried AugenbroeAbstract:Sustainable Building Retrofitting has attracted serious research attention in recent years as it can significantly reduce energy consumption and thus help achieve energy reduction targets set by governments around the world. In this paper, a sustainable Retrofit decision-making model is developed to uncover the optimal set of Retrofit solutions according to local climatic conditions, Building features, and Retrofit costs. Net present value (NPV), a common method for analyzing the feasibility of a Building Retrofit solution, is used to determine the optimal Retrofit solution of existing high-rise residential Buildings in a temperate zone and hot summer-cold winter zone, involving prototypical 1990s apartments of 116 and 53 m2 floor areas respectively. This reveals that the lighting system, wall insulation, and upgraded window glazing are essential optimal Retrofit measures for the temperate zone, whereas the heating system and shading devices are also essential for the hot summer-cold winter zone. The results indicate that the optimal NPV can be obtained by pursuing a 40% energy saving, as it can result in energy saving of up to 50 kWh/m2/year and 95 kWh/m2/year at an average Retrofit cost of approximately USD 1.30 and 3.20 m2/year in the temperate and hot summer-cold winter zones respectively. The sensitivities associated with the most influential optimal NPV and energy savings input parameters are critically analyzed; these can be used by decision-makers to determine the risks and uncertainties related to various cost-effective Retrofit measures. The model can help in devising the most suitable sustainable Retrofit measures for existing Buildings commensurate with the energy reduction targets of policy and decision-makers in the two climate zones. It is also amenable to being adapted for other climatic zones to identify the most appropriate sustainable Building Retrofit for particular local climatic conditions and Building characteristics.
Xiaohua Xia - One of the best experts on this subject based on the ideXlab platform.
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ASCC - An optimization method for Building Retrofit planning based on a grouping method and notch test data
2019Co-Authors: Yuling Fan, Xiaohua XiaAbstract:The high level energy consumption of the Building sector is a common challenge faced by human beings. Building Retrofit is an effective way to reduce the energy consumption of the Building sector. To further promote the transition to a green Building sector, many green Building policies in the world are published. However, making a systematic whole-Building Retrofit plan optimally considering green Building policies requires to solve a nonlinear mixed integer optimization problem. In addition, the whole-Building Retrofit project must be supported by a comprehensive and expensive energy audit. This study proposes a simplified optimization method for whole-Building Retrofit considering energy performance certificate standard (EPC) based on a grouping method and notch test data, aiming at reducing the complexity of solving the optimization problem and eliminating the need of a detailed energy audit. A case study shows that 74% energy savings and an A rating from the EPC rating system can be achieved with a payback period of 51 months.
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energy efficiency Building Retrofit planning for green Building compliance
Building and Environment, 2018Co-Authors: Yuling Fan, Xiaohua XiaAbstract:Abstract To promote sustainable development and expedite the progress on moving to a green Building sector, the government of South Africa has developed an energy performance certificate (EPC) standard for Buildings. A Building is required to obtain a certain rating from the EPC in order to comply with the country's green Building policy. Therefore, finding optimal Retrofit plans for existing Buildings are essential given the high investments involved in the Retrofit of Buildings that do not currently comply with the policy. This paper presents an optimization model to help decision makers to identify the best combination of Retrofit options for Buildings to ensure policy compliance in the most cost-effective way. The model determines optimal Retrofit plans for a whole Building in a systematic manner, taking into account both the envelope components and the indoor facilities. A roof top PV system is utilized to reduce the usage of electricity produced from fossil fuels. The model breaks down the long-term investment into yearly short-term investments that are more attractive to investors. Tax incentive program available in the country is taken into account to offset the long payback period of the investment. Economic analysis is also built into the model to help decision makers to make informed decisions. The Retrofit of an existing office Building is taken as a case study. The results show that 761.6 MWh energy savings and an A rating from the EPC can be obtained with a payback period of 70 months, which demonstrates the effectiveness of the model developed.
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Building Retrofit optimization models using notch test data considering energy performance certificate compliance
Applied Energy, 2018Co-Authors: Yuling Fan, Xiaohua XiaAbstract:Abstract Determining a systematic whole-Building Retrofit plan for envelope components and indoor appliances to achieve targets such as cost savings and policy compliance is a challenging task. To be specific, the systematic whole-Building Retrofit problem, when solved by an optimization approach, is highly complicated. It is sometimes even impossible to find a solution with given computation resources and algorithms. In addition, a costly comprehensive bottom-up audit is required to establish the parameters of the problem. This study presents two models to reduce the complexity of the systematic whole-Building Retrofit optimization problem. Firstly, the proposed models use the grouping concept to optimize the Retrofit of subsystems in a Building instead of individual components/appliances, which reduces the dimension of the problem effectively. Secondly, the models use so-called ‘notch test’ data, which are sampled and verified savings of an intervention, to eliminate the need for bottom-up energy audits. This further simplifies the Retrofit optimization problem and reduces the Retrofit cost. The models are based on our previous work and aim at energy savings maximization and payback period minimization, considering the green Building policy and tax incentive initiatives. A case study shows that about 2530 MWh energy savings and an A rating from the energy performance certificate standard can be obtained with a payback period of 59 months, which verifies the feasibility and effectiveness of the models proposed.
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An optimal model for a Building Retrofit with LEED standard as reference protocol
Energy and Buildings, 2017Co-Authors: Maria Michael, Lijun Zhang, Xiaohua XiaAbstract:The selection of facilities to be replaced during a Building Retrofit can be challenging due to conflicting interests such as budget constraints, Building minimum requirements, human comfort, and environmental goals. In order to assist decision-makers with the appropriate selection of facilities, this paper presents a multi-objective optimization model aiming at optimizing the Retrofitting costs, energy savings, water savings, payback period, and points earned under the Leadership in Energy and Environmental Design (LEED) rating system. This work introduces green Building certification as an objective for existing Building Retrofits. The benefits of an existing Building Retrofit and green Building certification to the Building owner includes reduced operating costs, carbon footprint, and improved air quality. The developed model considers a wide range of facilities and saving measures as Retrofitting options for the energy and water efficiency credit categories of LEED. A case study of a hotel in South Africa is presented to demonstrate the feasibility of the proposed model and optimization approach.
Kaushik Biswas - One of the best experts on this subject based on the ideXlab platform.
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Whole Building Retrofit using vacuum insulation panels and energy performance analysis
Energy and Buildings, 2019Co-Authors: Kaushik Biswas, Tapan Patel, S. Shrestha, Douglas Smith, Andre Omer DesjarlaisAbstract:Abstract Vacuum insulation panels (VIPs), due to their high thermal performance, provide an attractive alternative to traditional Building insulation materials, especially as an option for Retrofitting old, poorly insulated Buildings. This article describes the complete Retrofit of all exterior walls of a single-story Building in a cold climate using VIPs. A recently-developed low-cost VIP, called modified atmosphere insulation (MAI), was used in this study. Two Buildings of near-identical construction were studied, with one remaining unaltered and serving as the baseline while the other served as the Retrofit Building. The VIPs or MAI panels proved to be a feasible and durable option for Retrofitting Building envelopes. Thermal performance of both Buildings was analyzed using in-situ temperature and heat flow sensors. Numerical models of the two Buildings were created, benchmarked using experimental data and used for predictions of annual energy savings due to the addition of MAI panels to the exterior walls. The models predicted significant reduction in the annual heating energy consumption in the Retrofitted Building compared to the baseline Building.
