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The current estimation practice in construction projects greatly needs upgrading, as there has been no improvement in the cost overrun issue over the past 70 years. The purpose of this research was to develop a new multiple regression analysis (MRA)-based model to forecast the final cost of road projects at the pre-design stage using data from 43 projects in New Zealand (NZ).

The research used the case study of 43 completed road projects in NZ. Document analysis was conducted to collect data, and statistical tests were used for model development and analysis.

Eight models were developed, and all models achieved the required F statistics and met the regression assumptions. The models’ mean absolute percentage error (MAPE) was between 21.25% and 22.77%. The model with the lowest MAPE comprised the road length and width, number of bridges, pavement area, cut and fill area, preliminary cost and cost indices change.

The model is based on road projects in NZ. However, it was designed to be able to adapt to other contexts. The findings suggest that the model can be used to improve traditional conceptual estimating methods. Past project data is often stored by the project team but rarely used for analysing and forecasting purposes. This research emphasises that past data can be effectively used to predict the project cost at the pre-design stage with limited information.

No research was conducted to adopt cost modelling techniques into the conceptual estimation practice in the NZ construction industry.

Cost overrun in infrastructure projects is a constant concern, with a need for a proper solution. The current estimation practice needs improvement to reduce cost overruns. This study aimed to find possible statistical modelling techniques that could be used to develop cost models to produce more reliable cost estimates.

A bibliographic literature review was conducted using a two-stage selection method to compile the relevant publications from Scopus. Then, Visualisation of Similarities (VOS)-Viewer was used to develop the visualisation maps for co-occurrence keyword analysis and yearly trends in research topics.

The study found seven primary techniques used as cost models in construction projects: regression analysis (RA), artificial neural network (ANN), case-based reasoning (CBR), fuzzy logic, Monte-Carlo simulation (MCS), support vector machine (SVM) and reference class forecasting (RCF). RA, ANN and CBR were the most researched techniques. Furthermore, it was observed that the model's performance could be improved by combining two or more techniques into one model.

The research was limited to the findings from the bibliometric literature review.

The findings provided an assessment of statistical techniques that the industry can adopt to improve the traditional estimation practice of infrastructure projects.

This study mapped the research carried out on cost-modelling techniques and analysed the trends. It also reviewed the performance of the models developed for infrastructure projects. The findings could be used to further research to develop more reliable cost models using statistical modelling techniques with better performance.

The construction industry is complex, human-intensive and driven by monetary values. Hence, disputes are widespread. Initial conflicts among parties may develop into a disastrous dispute that costs the project success and good relationships and affects stakeholders' expectations. There has been a focus on causes of construction-related disputes, and studies over the past three decades have attempted to identify a more comprehensive list of reasons for disputes. Some of these studies' limitations were geographical, project delivery methods and project types. The purpose of this study is to identify the most recent and conclusive list of causes of disputes based on current literature by undertaking a systematic literature review (SLR).

Considering the large number of studies that focused on causes of disputes, this study aims to develop a comprehensive list of causes, using a SLR, as it ensures that all previous articles in multiple databases are reviewed to produce a comprehensive outcome. A six-stage SLR was followed from background study to analysis and reporting.

Not surprisingly, the number of publications has increased over time, most from the Middle East region. The interconnected nature of the causes was widely emphasised. The SLR has produced eight common core causes of disputes. They are: poor contractual arrangements, employer-initiated scope changes, unforeseen site changes, poor contract understanding and administration, contractor’s quality of works, the inability of the contractor to achieve time targets, non- or delayed payments and poor quality of design. The majority of previous authors realised that disputes could be avoided by parties’ involvement during the early stages, avoiding being opportunistic and acting collaboratively.

Even though numerous studies have been carried out to identify the causes of disputes in the construction industry, none did a SLR. This study aggregates all the previous studies that focused on construction-related disputes systematically. Categorising causes based on the party primarily responsible help various stakeholders by providing a distinct list of factors to avoid that contribute to disputes.

In light of climate change, the design and construction of buildings needs to shift from conventional to lower-carbon practices to maximise carbon reduction. Over the past few years, the zero carbon buildings (ZCBs) approach has been promoted worldwide as an effective way to reduce environmental impacts and mitigate climate change. Although zero-carbon policies, technologies, processes and products are widely available in the construction market, construction stakeholders play an important part in adopting relevant strategies to implement ZCBs successfully. This study investigates the knowledge of construction stakeholders involved in the design and construction of buildings regarding zero carbon initiatives in New Zealand.

The research was conducted using a literature review and an online questionnaire survey with various New Zealand's construction stakeholders.

The findings indicate a low level of knowledge regarding the design and construction of ZCBs. To successfully deliver ZCBs, the study suggests that construction stakeholders must have their self-awareness increased, especially in improving knowledge of whole-of-life embodied carbon reduction. The governments and construction sectors should devote more effort to establishing training programmes and knowledge-sharing platforms to improve stakeholder knowledge in carbon literacy, building assessment methods, energy modelling and life cycle assessment.

The research implications may assist the real-world uptake of the ZCBs approach by offering academics and practitioners an insight into the ZCBs knowledge gaps.

Any building refurbishment is challenging and school buildings offer no exception. They are increasingly in need of refurbishment due to their age and evolving teaching and learning. The purpose of this paper is to present an overview of literature on sustainable refurbishment so as to identify key lessons from selected successful refurbishment projects. The review findings are expected to contribute to the development of refurbishment plans in an effective and innovative manner that should extend building’s service life, focus on resource efficiency, and comfort their users. It will also contribute to knowledge base of refurbishment and suggest future directions for research.

The paper has undertaken a literature review on the sustainability assessment of buildings and frameworks for sustainable refurbishment. Besides, the work also provides a review of recent successful refurbishment projects to collect and structure systems experiences which can be adopted in developing a sustainable refurbishment strategy for school buildings.

Findings include three groups of lessons in terms of reasons, process and barriers in the selected refurbishment projects that assist stakeholders to prepare a suitable refurbishment plan for their school buildings. The potential of 3D scanners and BIM applications in the refurbishment process will also be reviewed in order to develop a proposed framework of 3D scanner vs BIM for the refurbishment process. Recommendations highlight the role of a national strategy as a driving factor for applying the advantages of information technology to enhance optimal solution selection processes to get better and more sustainable results.

The conceptual framework for 3D scanner and BIM applications within sustainable refurbishment for school buildings is currently under researched, and the findings aimed to address such a gap when considering 3D scanners and BIM applications in the refurbishment process.

This paper aims to develop an integrated and comprehensive framework for building and property management (BAPM) for state schools in New Zealand. The results are expected to clarify the complicated process and provide a guide for school boards to manage their property effectively and efficiently. It also seeks to explore the relationship between the key stakeholders and how this impacts the BAPM.

In addition, to review literature, qualitative data were obtained through semi-structured interviews with 16 top managers in state schools. The data analysis results were used to develop the framework using the integration definition for process modelling.

The findings contribute to understanding the processes in the BAPM in state schools of school board members by adding input, output, control and mechanism elements in each activity of the processes. The systematic models with main activities and people involved are presented as a guide for school boards in state schools in New Zealand. Challenges and issues in the processes are also identified to draw further study for both school boards and the Ministry of Education.

The research was conducted with the participation of stakeholders who are sampled from top managers in state schools in New Zealand. A larger scale of participants from other schools may generalise the findings further.

The research findings are based on the needs and requirements of the stakeholders to understand, implement and control the BAPM for their schools and aid them to achieve the best value for money spending on the management.

The paper highlights the complexity of the BAPM in schools, presents the roles and responsibilities of the school stakeholders and proposes a systematic framework to assist the school managers in this management process.

Reconstruction processes after an earthquake require estimating repair costs to decide on whether to repair or rebuild. This requires an accurate post-earthquake cost estimation tool. Currently, there are no post-earthquake loss estimation models to estimate repair costs accurately. There are loss assessment tools available, namely, HAZUS, performance assessment calculation tool (PACT), seismic performance and loss assessment tool (SLAT) and seismic performance prediction tool, which have not been specifically used for post-earthquake repair cost estimation. This paper aims to focus on identifying factors that need to be considered when upgrading these tools for post-earthquake repair cost estimation.

The research was conducted as an exploratory study using a literature review, document analysis of the PACT, SLAT and HAZUS software and 18 semi-structured interviews.

The research identified information sources available for estimation and factors to be considered when developing estimations based on the information sources.

The data was collected from professionals who were involved mostly in housing repair work in New Zealand. Therefore, impact of these repair work factors might vary in other forms of structures such as civil structures include bridges and the country as a result of varying construction details and standards.

The identified factors will be used to improve the loss estimation tools are such as PACT and HAZUS, as well as to develop a post-earthquake repair cost estimation tool.

Currently, the identified factors impacting post-earthquake damage repair cost estimations are not considered in loss estimation tools. Factors identified in this research will help to develop a more accurate cost estimation tool for post-earthquake repair work.

Cost overrun is one of the critical issues faced in construction projects, as nine out of ten projects will likely go over the budget. In particular, transportation infrastructure (TI) projects, such as roads and bridges, are vastly affected by cost overruns, which can delay the entire project. This research intends to identify the factors affecting the cost overruns in New Zealand (NZ) TI projects.

The research was conducted using a questionnaire survey involving ninety-two participants experienced in infrastructure project estimation in NZ. Quantitative methods were used to analyse the data.

Fifty-three factors were identified through literature under ten categories. Based on the survey, ten significant factors were identified with a high grade of importance. The three most critical factors were “frequent design changes,” “poor planning and scheduling” and “inadequate tender documentation.” It was found that the cost overrun is primarily affected by the pre-contract stage causes.

The data were collected from professionals involved in NZTI projects. Therefore, the implications may be different for other contexts.

The results will improve the current estimation practice by developing a new statistical model considering all the significant variables for NZTI projects.

Although much research is done to identify these factors, they are only considered in a few statistical cost models. These new statistical models mainly focused on technical variable factors similar to the current standard estimation process. However, the results of this research, qualitative and quantitative factors, will be used for the future cost model.