33 research outputs found

    Developing whole-life cost models for retrofit options in office buildings

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    Office retrofit building projects have become a subject of increased attention among building researchers in the United Kingdom, and in many economically advanced nations. Existing whole-life costing models have however, not proven to be robust enough to deal with these retrofit building scenarios. There is a growing body of evidence that conceptual modifications in the mechanics of whole-life cost modelling, could facilitate improvements in the long-term cost assessment of buildings. Recent research has made a case for the existence of revocability and disruption, in the appraisal of retrofit building investments. Revocability, connotes the potential for variability, in the future cost projections of a building over its estimated life. Disruption relates to the diminished building use, or unusability, over a period of implementing a retrofit initiative. Existing whole-life cost models have however, not recognised the implications of revocability and disruption in their framework. This study conducts an investigation into the whole-life costing of office retrofit building projects, and develops a Fuzzy New-Generation Whole-life Costing approach. Two office retrofit building projects are adopted, to appraise the identified issues in the whole-life costing framework. A number of building configuration permutations (BCPs) constituting different retrofit options, are developed in both projects. The potential implication of revocability and disruption, are evaluated based on probability and fuzzy logic principles respectively. Sensitivity analysis is applied to discount rate assumptions over the estimated lives, of the projects considered. The Spearman’s rank correlation coefficient is used in analysing the ranking results of selected projects. This provided an assessment of the relative preference of BCPs in the projects.Results from the case studies show 1) disruption issues account for up to 12% of initial capital costs; 2) revocability accounts for up to 35% of initial capital cost, over a 20-year life; up to 119%, over a 60-year life; 3) up to 2% underestimation in the whole-life cost, over a 20-year life; and up to 45% underestimation, over a 60-year period, in the SPACE project; 4) up to 9% underestimation in the whole-life cost, over a 20-year life; and up to 53% underestimation, over a 60-year life, in the MS project

    Evaluating the whole-life cost implication of revocability and disruption in office retrofit building projects.

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    Retrofit buildings are becoming popular in the United Kingdom as well as many parts of the advanced economies. Existing whole-life costing models have however, not proven to be robust enough to deal with building retrofit scenarios. Recent research has made a case for the existence of revocability and disruption in building retrofit investments. This paper evaluates the whole-life cost implication of revocability and disruption in office retrofit building projects. The potential implication of revocability and disruption are evaluated based on probability and fuzzy logic principles respectively. Two case study projects are selected to appraise the economic potentials of revocability and disruption. It was found that the average cost of revocability relative to the initial capital cost can be up to 119% over a 60-year life. It was also found that the average cost of disruption relative to the initial capital cost can be up to 12%. Future studies will utilise sensitivity analysis in assessing the relative preference of building retrofit configurations in office building projects. The external validity of this work is moderate, as the intention is to establish analytical generalisation rather than statistical generalisation for office retrofit building projects

    Developing whole-life cost models for retrofit options in office buildings

    Get PDF
    Office retrofit building projects have become a subject of increased attention among building researchers in the United Kingdom, and in many economically advanced nations. Existing whole-life costing models have however, not proven to be robust enough to deal with these retrofit building scenarios. There is a growing body of evidence that conceptual modifications in the mechanics of whole-life cost modelling, could facilitate improvements in the long-term cost assessment of buildings. Recent research has made a case for the existence of revocability and disruption, in the appraisal of retrofit building investments. Revocability, connotes the potential for variability, in the future cost projections of a building over its estimated life. Disruption relates to the diminished building use, or unusability, over a period of implementing a retrofit initiative. Existing whole-life cost models have however, not recognised the implications of revocability and disruption in their framework. This study conducts an investigation into the whole-life costing of office retrofit building projects, and develops a Fuzzy New-Generation Whole-life Costing approach. Two office retrofit building projects are adopted, to appraise the identified issues in the whole-life costing framework. A number of building configuration permutations (BCPs) constituting different retrofit options, are developed in both projects. The potential implication of revocability and disruption, are evaluated based on probability and fuzzy logic principles respectively. Sensitivity analysis is applied to discount rate assumptions over the estimated lives, of the projects considered. The Spearman’s rank correlation coefficient is used in analysing the ranking results of selected projects. This provided an assessment of the relative preference of BCPs in the projects.Results from the case studies show 1) disruption issues account for up to 12% of initial capital costs; 2) revocability accounts for up to 35% of initial capital cost, over a 20-year life; up to 119%, over a 60-year life; 3) up to 2% underestimation in the whole-life cost, over a 20-year life; and up to 45% underestimation, over a 60-year period, in the SPACE project; 4) up to 9% underestimation in the whole-life cost, over a 20-year life; and up to 53% underestimation, over a 60-year life, in the MS project

    A qualitative study of traditional healthcare practices: evidence from Ilorin less city

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    The object of research: This study aimed to explore different forms of healthcare practice in Egbejila an Ilorin less city, Nigeria. The investigated problem: Throughout the world, traditional healthcare practice leads the edge with regards to healthcare delivery for humanity. It follows that rural inhabitants marshal various forms of healthcare practice. This study investigated peculiar healthcare practices performed by traditional healthcare practitioners in Egbejila a rural Nigeria. The main scientific results: The research study unveiled different and various dimensions and approaches of healthcare practice that are visualized and sustained as an indispensable component of continuity and survival of human entity. The area of practical use of the research results: The results of this research study gave insight to various traditional healthcare services being sought after by rural inhabitants of variant cultural, religious, socio-political and economic backgrounds aside the orthodox medicine. Scope of the innovative technological product: The study adopted purposive sampling procedure for the selection of key informants. A total of twenty-five (25) key informants were purposively selected. Data obtained through the recorded interviews were transcribed into Microsoft Word and was analyzed by using N-Vivo softwar

    A systematic review of barriers to implementing net zero energy buildings in Australia

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    Building operations use 45% of the total energy in Australia, and Net-Zero Energy Buildings (NZEBs) are instrumental in achieving net zero emissions by 2050. However, research reveals that various factors hinder NZEB adoption in Australia, and it is imperative to contextualise the barriers, thereby highlighting clear gaps that can be addressed to enhance the implementation of NZEB in Australia. This study presents a systematic literature review and bibliometric analysis to examine the barriers that hinder the implementation of NZEB contextualised within the Australian building industry. The paper's novelty resides in its contextualisation of barriers to NZEB thereby highlighting clear gaps that can be addressed to enhance the implementation of NZEB in Australia. Emergent results reveal the most impactful barriers experienced and the inter-relatedness between barriers and their effects on each other. These identified barriers are also compared with comparable countries, including the UK, China, Italy and the US. New insight and knowledge acquired provide a basis for assessing potential solutions to the main barriers. Findings show that a lack of knowledge, climate issues, and cost issues, in addition to government policy factors, are considered primary barriers encountered by the industry, hindering the achievement of NZEBs. It is imperative that future studies and initiatives counteract these impacts to realise a better implementation of NZEB in the Australian context

    Mapping relational efficiency in neuro-fuzzy hybrid cost models.

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    Significant improvements are achievable in the accuracy of cost estimates if cost models adequately incorporate issues of flexibility and uncertainty. This study evaluates the relational efficiencies of the fuzzy composition operators “ the max-min and max-product, in establishing the final cost of water infrastructure projects. Cost and project data was collected on 1600 water infrastructure projects completed in Scotland between 2000 and 2011. Neural network is first used to develop relative weightings of relevant cost predictors. These were then standardized into fuzzy sets to establish a consistent effect of each variable on the overall target cost. The strength and degree of relationship of the normalized cost predictor weightings and the fuzzified project attributes were combined using the max-min and max-product composition operators to obtain project cost predictions. The predictions from the two composition operators are compared with the actual cost figures. Results show comparable performance in the efficiency of the composition operators. Based on statistical correlations, the max-product composition operator achieved on average a deviation of 1.71% while the max-min composition had an average deviation of 1.86%. Improvements in the relational efficiency of neuro-fuzzy hybrid cost models could assist in developing a robust framework for realistic cost targets on construction projects

    Cost Profiling of Water Infrastructure Projects

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    © 2018 American Society of Civil Engineers. The expected final budgeted costs of infrastructure assets are often exceeded during project delivery. Being able to determine the likelihood of changes to the final budget can enable clients to implement strategies to manage and control costs during construction. To understand the changing nature of costs, this paper examines the cost profiles of 1,093 water infrastructure projects that were delivered by a water utility company. Cost overruns were experienced in 656 projects. Only 1 project was delivered on budget; the remaining 436 were completed under final budget approval. A mean cost overrun and underrun of + 19.97 and -32%, are found, respectively. The best-fit distribution for cost overruns and underruns for determining their probability of occurrence is calculated. The research moves beyond examining the cost performance of heterogeneous data sets that have dominated previous studies to the use of a homogeneous sample, which enables more-reliable contingency forecasts to be determined
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