The construction industry consumes a significant amount of resources annually, generates significant waste and produces a host of emissions. This study develops a framework and integrates three different approaches -Lean, Green and Six Sigma -in a systematic approach with the goal of improving the quality and environmental impacts of the construction process. A case study of pile cap installation was conducted to illustrate the application of the framework and associated results. The study highlights two issues within the pile cap construction process responsible for waste: delay and potential errors in material estimation and ordering. It describes the environmental impact arising from waste, and analyzes the root causes behind waste generation to enable improved process performance. A survey of construction professionals regarding the causal factors of waste in everyday construction activities identified 'design changes during construction' as responsible for 60% of waste occurrences during construction and thus confirm results from the literature. In conclusion, the LeanGreen-Six Sigma framework offers a comprehensive, multi-stage approach for process improvement and minimization of life cycle environmental impacts.

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Environmental and economic cycles under varying geopolitical uncertainties can lead to unsustainable patterns that significantly and negatively affect the welfare of nations. With the ever-increasing negative environmental and economic impacts, the ability to achieve sustainability is hindered if the implications are not properly assessed in challenging geopolitical crises. The infrequent and fluctuating nature of these challenging geopolitical settings causes disregard and neglect for exploration within this issue. In this study, a comparative life cycle assessment was conducted as a method to evaluate the environmental and economic impacts of construction material flow across country boundaries. Based on the results found from the life cycle assessment, an environmental forecast and sensitivity analysis were established. Considering the State of Qatar as a case study, asphalt and bitumen, cement, limestone, sand, and steel were analyzed from gate-to-gate depending on transportation mode and distances used within both the pre-crisis and post-crisis sub-periods, comparing carbon emissions and costs. The results showed that the mode of transport plays a significant role in terms of carbon dioxide emissions as opposed to distance traveled. However, the increase in distance coupled to the majority shift from land to sea-based transport resulted in an overall increase in carbon emissions and costs post-crisis. In addition, the analysis of the environmental and economic impact assessment using the average CO2 equivalent (CO2-e) per kilogram and the unit price of the five primary construction materials has shown a significant, 70.68% increase in global warming potentials (GWP) after the crisis, coupled with an increase in the overall cost. An assessment of environmental and economic impacts during geopolitical uncertainties allows for the significant ability to realize sustainable measures to greatly reduce economic and environmental degradation.

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It has been over three decades since the term “sustainable development” was coined in Brundtland’s report in 1987, and 28 years have passed since the world’s first sustainability assessment method for buildings was founded by the Building Research Establishment in UK in 1990. During these three decades, many sustainability standards, codes, and rating systems were created and used to help in designing, constructing, maintaining, rating, and labeling buildings with attaining the principles of sustainability. Yet by looking at the Arab world at the beginning of 2019, one can argue that, although the Arab countries have dedicated the effort and budget to save energy, water, and natural resources, the region as a whole is still struggling to shift the paradigm of the building industry from conventional to sustainable. This struggle raises some questions; are there any challenges that Arab countries must overcome to leap forward to a prosperous sustainable building design and construction practices? Why are existing green building rating systems such as Estidama in United Arab Emirates, global sustainability assessment system (GSAS) in Qatar, and ARZ in Lebanon lagging behind the trends of green building rating systems in the developed countries? What are the coordinated steps needed to expedite this movement across the region? The current study explores the limits and potentials of the green building industry in the Arab world through analysis of the green building initiatives, academic scholarship activities in architecture and engineering sectors, and feedback from green building professionals across the Arab world. This article introduces a theoretical framework to expedite the green building movement in the Arab region; the framework is shaped by the environmental, social, and economic factors that are crucial to the transformation of the building industry from conventional to sustainable. The study seeks to support a line of research that could help governments in the Arab world catch up with the global green building trends.

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Life cycle assessment (LCA) is a tool to quantify the environmental impacts of a product or system. This tool is used to assess environmental impacts of buildings over their lifespan. LCAs performed on standard buildings showed that the use phase dominated the impacts over the course of a building's lifespan. Consequently, building energy efficiency was the target of reduction measures and high-performing buildings began to emerge. The design of living buildings followed, which are buildings that are defined as being net-positive energy and water. In these energy efficient buildings the significance of the use phase diminishes, shifting the focus to other life cycle stages. This research includes a whole-building LCA of a living building that focuses on the impacts from green building materials, a decentralized water system, a net-positive use phase, and the disposal of structural materials. The material processes used in this LCA were modified by removing the use of highly toxic chemicals per the product submittals; results showed carcinogenic impacts were decreased by up to 96%. The septic system, which is not aerated, used for wastewater treatment contributes to 37% of the global warming potential (GWP, kg CO2eq) for the whole building's lifespan due to methane emissions. The solar panels on-site generate more electricity than the site demands, allowing for 44,000kWh of green energy to be returned to the grid. Lastly, a scenario analysis was performed on multiple waste streams for materials of two structural models (lumber or steel) with a concrete foundation. Results showed that based on the frame and waste stream selected, the end of life GWP impacts could vary from +14,000kg CO2eq to-10,500 kg v CO2eq for the as-built structure. This whole-building LCA aims to identify and mitigate hotspots of the case study building, and to reduce life cycle impacts of living buildings moving forward. vi TABLE OF CONTENTS