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Purpose: This paper proposes an evaluation model for prefabricated construction to guide a supply chain with controllable costs. Prefabricated construction is prevalent due to area limitations. Nevertheless, the development is limited by budget control and identifying the factors affecting cost. The degree of close collaboration in the supply chain is closely interconnected with cost performance that includes direct and indirect factors. This paper not only quantizes these factors but also distinguishes the degree of influence of various factors. Design/methodology/approach: System dynamics is applied to simulate and analyze the construction cost factors through Vensim software. It can also clarify the relationship between cost and other influencing factors. The input data are collected from an Internet of Things (IoT)-enabled system under a Building Information Modeling (BIM) system and Hong Kong government reports. Findings: Simulation results indicate that prefabricated construction cost is mainly influenced by government promotion degree (GPD), working pressure from on-site construction (WPOSC), prefab quality (PQ), load-bearing capacity per vehicle (LBPV) and mold quality (MQ). However, it is more sensitive toward GPD, which indicates that the government should take measures to promote this construction technology. On-site worker management is also essential for the assembly process and indirectly influences the construction cost. Research limitations/implications: This paper quantifies indirect influential factors to clarify the specific features for prefabricated construction. The investigated factors are limited. Practical implications: The contractor can identify all factors and classify the levels of influence to make decisions under the supply chain system boundary. Social implications: The input data are collected from an IoT-enabled system under a BIM system and Hong Kong government reports. Thus, the relationship between construction cost influential factors can be investigated. Originality/value: This paper quantifies indirect influencing factors and clarifies the specific features in prefabricated construction. The contractor could identify these factors to make decisions and classify the levels of influence under the supply chain system boundary. [ABSTRACT FROM AUTHOR]

This study aims at investigating the cost-effectiveness of developing a new type of house, the floating house, as a solution to land scarcity in metropolitan coastal cities. Under value management framework, the "function analysis system technique" diagram was established to identify the functions of land-based and floating houses. Participants with different backgrounds shared their views through the two designed questionnaires, assisting in determining the cost allocation and functional performance levels of the houses. Fuzzy set theory was utilized to convert the collected professional knowledge and public opinions into numerical measurements. The obtained function values disclosed that, despite weaknesses in the conventional living and structural issues, the floating house still shows competitiveness and opportunities in customer attraction, environmental sustainability, and encouraging local tourism. This paper offers the evidence and reference to both practitioners and governments seeking for a better value of the money they invest in future floating house projects. [ABSTRACT FROM AUTHOR]

It is generally accepted that the extra construction costs involved in the construction of green buildings will result in benefits including lower operation costs, higher sale/rental prices, and better sustainability performance. However, there has been little recognition of construction waste minimization (CWM) as one of the important benefits of sustainability performance as designated in green building. This paper aims to provide a better understanding of the cost benefit of green buildings with respect to CWM by using big data in the context of Hong Kong. The study is innovative in that it conducts a cost-benefit analysis specifically on CWM of green buildings by mining large-volume datasets. A surprise finding is that Hong Kong's green building rating system (GBRS), i.e. the BEAM Plus, has a negligible effect on CWM, while it generally increases construction costs by approximately 24%. Hence, the increased construction cost of green buildings cannot be offset by CWM if corresponding items in the BEAM Plus are not properly incentivized. This paper demonstrates the necessity of emphasizing CWM-related items in GBRSs and of taking appropriate measures to deal with them. It also provides better decision-support information on the increased construction costs and the attainable benefits of green building that developers may wish to consider when initiating a green building project. [ABSTRACT FROM AUTHOR]

• An optimal width allocation policy for traffic lanes and footpaths is developed. • Optimal lane width is 5.4 m when user and agency costs are equally important. • Hong Kong road agency places a higher weight on each dollar of user cost. • Allocation to footpaths can reflect the importance placed on pedestrian safety. Introduction: Walkability continues to attract great attention from urban planners, designers, and engineers as they recognize not only the merits of pedestrian facilities in terms of the health benefits but also their demerits in terms of accident risk to pedestrians. Wide footpaths improve the pedestrian environment and experience, and thereby motivate travelers to walk as much as possible. However, if footpaths are too wide, they may leave a smaller space for the roadway. On the other hand, wide road lanes may lead to higher road vehicle safety but are costly to construct and maintain and also may leave little space for the footpath. Evidently, for a fixed urban space, what is needed is an optimal balance between the vehicle lane and pedestrian path. This problem is encountered routinely in dense cities including Hong Kong where land availability is severely limited. Method: To address the issue, this paper first establishes safety performance functions (SPFs) for the pedestrian space and the road space, using the random-parameter negative binomial regression. The results indicate the extent to which road lane and footpath width changes are associated with changes in in-vehicle occupant and pedestrian casualties. Then the paper uses the SPFs to develop a methodology for optimizing the width allocations to the road lanes and footpaths, duly considering the user (safety) costs and agency (construction) costs associated with each candidate allocation of the widths. Finally, the paper analyzes the sensitivity of the optimal solution to the relative weights of user cost and agency cost. Results: When user and agency costs are considered equally important, the optimal lane width is 5.4 m. Conclusion: It is observed that the road space allocation ratio used by the Hong Kong road agency suggests that the agency places a higher weight to user cost compared to agency cost. Practical Application: The findings can help incorporate design-safety relationships, and the stakeholders (agency and users) perspectives in urban road and footpath design. [ABSTRACT FROM AUTHOR]

A widely recognized theme of construction economics suggests that the cost of construction per square meter increases as building height rises. However, over a number of years, research conducted regarding the height and cost issue has established a classic relationship between the two factors which can be represented by a U-shaped curve. This paper describes the study of the height-cost relationship of high-rise residential buildings in Shanghai in terms of the total construction cost and elemental costs while considering the context and commonality of buildings. This research was developed as an extension of the previous work, which examined data for buildings in Hong Kong. Initial findings indicate that the curves illustrating the relationships between height and cost of residential buildings in Shanghai and Hong Kong exhibit different profiles. The dissimilarities indicate that different sets of criteria should be applied in the judgment of height that affects cost in different locations. In terms of elemental costs, the findings suggest that there are differences in the way these costs react to changes in the building height. [ABSTRACT FROM AUTHOR]

Purpose – The purpose of this study is to estimate an empirical model for new office space development starts, based on the theoretical treatment of urban growth. The study introduces a new parameter, namely, office space-usage pattern, to the office space development equation and tests whether developers respond to non-price measures in deciding to commence new developments. Design/methodology/approach – The study first introduces a co-integration approach based on an error correction model to test for long-run relations and short-run dynamics of new office space development. A multivariate regression model is then introduced to identify significant determinants that influence office development starts. The study uses annual data over a time span of 30 years. Findings – Estimated results provide strong evidence that the newly introduced parameter exerts a positive impact on new office space development. It suggests that if the average floor space per employee changes by one percentage point, new office development starts would change by 1.5 percentage point, indicating even a marginal change in floor-space usage per employee (SPE) would have a significant impact on new office space development. Empirical estimates also suggest a strong response of office development starts to the lagged land supply and office space stock. Research limitations/implications – The paper raises the concern about the importance of non-price measures of the supply-side of the office market. There is scope to address the research questions using better data sets. It is also possible to model the supply adjustment process more dynamically in an error correction framework. Practical implications – The findings would suggest that non-price measures, such as space-usage pattern, need to be taken into account when planning and estimating future office space needs. This finding provides valuable insight for our current knowledge on factors affecting new office supply. Originality/value – This is the first study to introduce office floor space usage as a determinant of office development starts in an urban growth conceptual framework for the Hong Kong office market. [ABSTRACT FROM AUTHOR]

The use of structural steelwork (SS) for buildings continues to grow worldwide owing to its sustainability benefits. However, the market share of SS in the building sector of Hong Kong greatly lags behind other markets. This paper focuses on providing a comprehensive understanding of the issues that greatly drive or inhibit SS adoption in Hong Kong from a project lifecycle perspective. The methodology encompasses both qualitative and quantitative approaches. Semi-structured interviews were conducted with 28 professionals from developer, structural engineering consultant, main contractor, steel specialist contractor, and steel stockholder companies. The results identified 12 driving factors and 25 barriers affecting SS adoption in Hong Kong. A questionnaire survey with 118 practitioners was carried out to identify the most important driving factors and barriers. The results revealed that "increased speed of construction" and "must-have requirements" were the two most important driving factors; while "shortage of skilled labor", "shortage of supervisors working directly under main contractors", "high construction costs", "shortage of experienced designers and draughtsmen", and "lack of education, training, and design experience on structural steelwork" were the five most critical barriers. This may imply that education and training are needed to improve knowledge and skills of professionals and workers, and thus to ensure an adequate supply of manpower. The findings of this study not only contribute to the existing body of knowledge on SS practices but also provide valuable references for helping practitioners and policymakers to promote sustainable construction methods within the building sector. • Increased speed of construction and must-have requirements are important drivers. • Manpower shortages in the design and construction phases are critical barriers. • High construction cost also inhibits the use of structural steelwork. [ABSTRACT FROM AUTHOR]

This paper probes the range of factor affecting construction project duration through a literature review and a pilot survey in Hong Kong. Time-cost models previously proposed in Australia and the UK are compared with data obtained in Hong-Kong and similarities are noted. The 111 responses to the detailed questionnaire issued in Hong Kong and the follow-up interview also indicate other factors that may significantly affect project duration. Of these productivity is examined here, while other factors will be probed in the second phase of this investigation. Time-floor area relationships are also examined and found to be significant. Projects are classified as public or private sector housing and other buildings, road and other civil engineering projects. Large sample in each category of construction project will be targeted to test the validity of the models and their parameters in Hong Kong as derived from the pilot survey. It is noted that standardization in public housing projects (as in Hong Kong and Singapore) leads to more consistency in durations, providing useful reference points for such studies. International comparisons are intended to test the models, parameters and significant factors relating to the timeframe of construction projects. [ABSTRACT FROM AUTHOR]

This paper investigates the validity of the triangular distribution assumption which is commonly adopted in Monte Carlo simulations of construction costs. The study begins with an examination of the asymmetric nature of the distribution of construction costs and deduces theoretically that the triangular distribution assumption leads to an upward bias in the probability of exceeding the conventional single figure estimate for the subsystem variables and therefore the system variable. This assumption is also inconsistent with the estimators' subjective perception. An experiment has been performed to generate empirical data that test the above theoretical arguments and assesses the magnitude of the bias, if it indeed exists. Subjective estimates of the construction costs of the ten major subsystems of electrical services contracts of government clinics in Hong Kong are examined. These estimates are extracted from seven experienced estimators. The results of the analysis of the data confirm that the underlying distribution of the subsystem costs is asymmetric with a long thin tail towards the right and that the triangular distribution assumption does in fact lead to bias in the subsystem input variables and therefore the simulated output system costs. An alternative modelling approach which can reduce the bias has also been outlined in this paper. [ABSTRACT FROM AUTHOR]

A method of measuring total-factor productivity (TFP) trends in the building is described in this paper. This method is improved version of the approach described in a paper by Chau and Walker in that it requires less restrictive assumptions and is theoretically less biased while requiring only slightly more data. With small modification, the same method can be used to measure other productivity trends corresponding to other productivity concepts. The data used in measuring TFP of Hong Kong's building industry are also different form those proposed in Chau and Walker. A number of modifications have been made. These modifications have been possible both as a result of work by Chau and the increased availability of statistics in recent years. One of the major difficulties in measuring TFP trends in the building or construction industry has been the lack of data. This is also one of the major reasons for the dearth of empirical studies in this area. Very few attempts have been made to solve the problem of data availability. Lowe recognizes the difficulties in obtaining suitable data for measuring TFP of the British construction industry. His suggestion, however, is to use capital measure the TFP of Hong Kong's building industry. Since construction cost and price data are usually more readily available in most countries, Chau and Walker's approach is potentially useful in these countries. There are, however, certain deficiencies in Chau and Walker's approach in that some of the underlying assumptions are relatively restrictive. As more statistics are now available in Hong Kong, this has rendered Chau and Walker's approach a crude tool for making full use of the data. This paper presents a modified approach which requires less restrictive assumptions and can make better use of the newly available data. [ABSTRACT FROM AUTHOR]

This article aims to identify and analyze the key benefits of adopting Guaranteed Maximum Price and Target Cost Contracts (GMP/TCC) over and above the traditional lump-sum contractual arrangement through an empirical questionnaire survey conducted in South Australia and compared with the findings in Hong Kong. The Mann-Whitney U Test indicated differences in perception between the two groups of respondents on the majority of the identified benefits. The study has provided an in-depth understanding of the perceived benefits of the GMP/TCC scheme, hence leading to a wider application of those alternative integrated procurement strategies in both regions for reference by the construction community at large. [ABSTRACT FROM AUTHOR]

Previous research on building pre-tender cost estimating stresses the importance of giving accurate estimates and minimizing estimating errors. Cost models, especially those mathematical models using mean square error or the like for model training and validation, often treat positive errors (overestimates) and negative errors (underestimates) of equal magnitude the same with an implicit assumption that the regret or disutility of positive errors (overestimates) is equal to that of negative errors (underestimates). A survey was conducted in Hong Kong to study estimating practice and in particular, the attitude of clients and estimators towards estimating errors. This involved the use of regression analysis to model the relative disutility of underestimates (in terms of overestimates) for four different building types. Both clients and estimators are found to be risk averse - tolerating overestimates more than underestimates - and, arguably, clients are satisfied with overestimates. However, they have contrasting views on the desired characteristics of estimates with clients considering the ability to identify cost sensitive elements to be more important than accuracy. In this regard, the formalization of value analysis as part of the cost advice function under typical cost consulting agreements should be the best form of improvement. [ABSTRACT FROM AUTHOR]

Plan shape indices are based on the geometry of the plan shape rather than on empirical data, and are problematic as they embrace implicit assumptions that are not tested empirically nor justified theoretically. Empirical research using data in Hong Kong confirms that these plan shape indices are much poorer predictors of unit construction costs than the variables used to construct the indices. This study also develops a method for constructing a plan shape index that is free from the unjustified assumptions implicit in existing plan shape indices; it involves an empirical cost model. Different functional specifications of the cost models are tested. The result rejects the linear model and other special case models such as semi-log and log-linear models. However, the reciprocal model is not rejected. This result suggests that a linear plan shape index can predict the amount of floor area that can be constructed with a fixed sum of money better than the construction cost per floor area. [ABSTRACT FROM AUTHOR]