Agricultural landscapes that are intensively farmed, as in western Europe, face the challenge of a transition to more sustainable systems. Although erosion rates are relatively low in western Europe, ...the agricultural landscape is confronted by the need to mitigate the off‐site impacts of erosion. An important challenge is that of disrupting connectivity between runoff and sediment sources, often farmers' fields, and freshwater systems or local communities. Mitigation strategies should include monitoring of erosion rates and off‐site impacts and a mix of engineered and alternative measures such as buffer strips and retention ponds. Also needed are supportive government policies and actions including awareness of institutional memory problems and the promotion of farmer education. For the future, the risk of climate change must be appreciated and built into the planning of comprehensive mitigation strategies. Our perspective is that the overall aim should be a ‘sustainable agricultural landscape’ and not simply a reduction of erosion and runoff on farmers' fields.
The popularity of developing off-site manufacturing (OSM) projects is increasing in the construction industry. Sustainability is an importance concern of OSM stakeholders, and it becomes imperative ...to comprehend the way these stakeholders perceive it. However, there is still a lack of related explorations in this research area. Thus, the research aims to identify sustainability perceptions of OSM stakeholders based on their business information. A qualitative content analysis was adopted to retrieve and analyze the business information from Australian OSM stakeholders' official websites. The results show 59 sustainability perceptions, with the most mentioned ones being “High quality”, “Customer-focused approach and customization”, “Cost effectiveness and affordability”, and “Innovation”. Moreover, the OSM stakeholders’ sustainability perceptions have covered the social, environmental and economic sustainability dimensions, and the social sustainability perceptions were more focused than others. The statistical analysis reveals that there are no significant differences between different types of OSM stakeholders regarding their top-ranked sustainability perceptions and their perception numbers. The research facilitates understanding of the nature of the OSM sustainability issue, and offers OSM stakeholders a platform of re-thinking their sustainability practice. It also builds a new foundation of developing sustainability management frameworks and assessment benchmarks for OSM projects.
•OSM stakeholders' sustainability perceptions were explored.•59 sustainability perceptions were identified.•The most mentioned sustainability perception is “High quality”.•The social sustainability perceptions are more focused.•The sustainability perceptions of different OSM stakeholders show homogeneity.
AbstractOff-site construction (OSC) has been regarded as an effective means of improving construction quality and efficiency. The adoption of OSC has been slower in developing countries such as China ...than in developed countries, and research on the barriers inhibiting the sector’s growth is inadequate. This paper aims to investigate the major factors inhibiting the adoption of OSC with reference to the Chinese construction market. Thirty factors influencing the use of OSC were identified through a literature review, questionnaire survey, and face-to-face interview with professionals in the construction industry. A questionnaire was sent out to developers in China, and 83 completed questionnaires were retrieved. Ranking analysis was used to identify 18 critical factors. The top three barriers are “absence of government regulations and incentives,” “high initial cost,” and “dependence on traditional construction methods.” Factor analysis enables grouping of the 18 critical factors into five categories, namely, “government regulations and policies,” “technological innovation,” “industry supply chain,” “cost,” and “market demand.” The paper also indicates that the most dominant of the five groupings pertains to regulations and policies. These findings provide a valuable reference for the developers to understand the major barriers to their decision making and for government bodies aiming at promoting OSC in the construction industry to put forward relevant policies and incentives.
This study reports on using inverse analysis to experimentally estimate the in situ hygrothermal properties of a prefabricated lightweight building envelope. On-site temperature and relative humidity ...data were measured for one year in the walls of an occupied detached house. Field measurements were then used to solve inverse problems for identifying effective specific heat, thermal conductivity, vapor resistance factor, as well as heat and moisture transfer coefficients. Fully coupled heat and moisture phenomena were analyzed. The importance of estimating hygrothermal properties for reliable model calibration in hygrothermal performance assessment was addressed. For this purpose, the annual heat and moisture fluxes through the interior wall surface were calculated using the effective properties estimated in this study and reference values from the literature. The greatest deviations were found in cold periods for the thermal response and warm periods for the hygric response. Literature benchmarks were shown to potentially overestimate the annual heat loss by 30 % and the annual moisture transport by 24 %. The present study shows how in situ hygrothermal characterization enables more accurate predictions of the hygrothermal behavior of wall assemblies.
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•Field data are used to assess inverse problems of heat and moisture transport.•Estimated effective properties differ by up to 50 % from literature references.•Model calibration enables simulations to better assess the in-situ wall behavior.•Database properties overestimate the annual thermal performance by around 30 %.•Database properties overestimate the annual hygric performance by around 24 %.
Off-site construction refers to a new building approach which moves the building process away from the physical site but into a controlled factory environment. There are numerous and significant ...benefits derived from the increased global adoption of off-site construction. In China, however, it is identified that a number of transferable driving factors have not been present, for example, strategic roadmaps, appropriate policies and sufficient workable guidelines. To investigate into the China’s off-site construction status quo under the backdrop of China’s new urbanisation, this study conducts an exhaustive review of the literature towards a total of 107 papers and 85 governmental documents published during the past three years, along with semi-structured interviews to a number of experienced stakeholders. According to the information acquired from the literature review and the interviews, this paper sets forth a scientific process of carrying out a strengths, weaknesses, opportunities and threats analysis, from which the advantages and barriers of implementing off-site construction in China are analysed. Last but not least, the body of knowledge that the state-of-the-art research works have seldom addressed are complemented, namely, top-to-bottom implementation roadmaps and strategies that could significantly contextualise the China’s National New Urbanisation Plan 2014–2020 and help the Chinese construction sector to improve its competency.
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•New-type urbanisation provides opportunities for offsite construction in China.•A strengths, weaknesses, opportunities, threats analysis is conducted.•Advantages and barriers of implementing offsite construction in China are presented.•Five critical strategies of promoting offsite construction in China are formulated.
The Architecture, Engineering and Construction sector requires an intense innovation process to reduce costs, intervention times, and improve energy performance. This is particularly true to increase ...the rate of deep renovations of the existing European building stock and therefore support the EU’s 2050 decarbonisation targets.In this scenario, prefabrication can be considered a game-changer for the construction industry: on the one hand, it enables the adoption of an industrial mindset to the design, manufacturing, and installation of façade components, with the related advantages in terms of time, cost and quality; on the other, it allows for the customisation of components thanks to digital, BIM-based design and fabrication tools. However, its adoption in retrofit operations is still limited due, among other factors, to a lack of practical experience and a limited number of actual demonstration cases.This paper introduces an operative guideline to support a more widespread use of prefabricated thermal insulation components for the energy retrofit of existing buildings in the framework of a BIMenabled design and construction process. The guideline highlights the information flow and the role of each actor at every stage of the design and delivery process.The proposed guideline is finally tested through its application to a case study to show the feasibility of the process and the advantages deriving from the adoption of an industrialised approach to façade retrofit in terms of faster installation times.
BIM in off-site manufacturing for buildings Abanda, F.H.; Tah, J.H.M.; Cheung, F.K.T.
Journal of Building Engineering,
November 2017, 2017-11-00, Volume:
14
Journal Article
Peer reviewed
Open access
The need to overcome challenges faced by construction industry has been at the core of many government reports. Most of the reports suggest the adoption of innovations including off-site manufacture ...and emerging Building Information Modelling (BIM) to overcome the challenges facing the industry. Current research has largely focused on the impacts of off-site manufacture and BIM independently applied on traditional construction methods. Due to the factory-based nature of off-site manufacture, the benefits of BIM on off-site manufacture have been widely argued to be far greater than those of traditional construction. However, studies about impacts of BIM on off-site manufacture are scarce with far too many on traditional construction. This study investigates the implications of BIM systems on off-site manufacture and traditional construction methods, with emphasis on the technological potential of BIM for off-site manufacture. The specific objectives of the study are threefold. Firstly, it examines how BIM can support off-site manufacture. Secondly, the paper discusses the benefits of BIM and explains how BIM can overcome barriers hindering the uptake of off-site manufacturing. Thirdly, due to the importance to measure the benefits to support wider adoption, an examination of the published quantitative benefits of BIM on off-site manufacture and traditional construction is undertaken. A critical appraisal of the literature was undertaken to achieve the aim of this study. The main findings are the identification of qualitative and quantitative benefits of: BIM on off-site manufacture, off-site manufacture and BIM on traditional construction. The findings reinforce the argument that BIM adoption on off-site manufacturing projects is a rapid, efficient and one of the best ways to improve on the long standing challenges that have plagued the construction industry for generations.
•Off-site manufacture (OSM) contributes to construction efficiency and productivity.•BIM facilitates the deployment of OSM.•BIM + OSM leads to greater efficiency and productivity in the construction industry.
Using off-site hydrogen can reduce CO2 emissions from urban buildings with limited renewable energy generation. We demonstrated the supply and usage of off-site green hydrogen using a pilot-scale ...hydrogen energy utilization system, Hydro Q-BiC®, for a commercial building. The off-site location supplied green hydrogen to the on-site system using high-pressure gas. By developing rapid-filling-type metal hydride tanks, we could safely fill 100 Nm3 of off-site hydrogen at <1 MPaG in approximately 1 h. The use of off-site green hydrogen in a 24 h operation of Hydro Q-BiC® can extend the operation time of fuel cells and significantly contribute to a reduction in CO2 emissions. Estimations indicate that gray hydrogen increases CO2 emissions, and CO2 emissions can be reduced to zero using a green-hydrogen supply of 300 Nm3. The results indicate that the type and quantity of supply of off-site hydrogen are important for reducing the CO2 emissions of buildings.
•Utilization of off-site hydrogen can help reduce CO2 emissions from urban buildings.•Hydrogen energy utilization system Hydro Q-BiC® developed for a commercial building.•Hydro Q-BiC® tested to demonstrate efficacy in reducing CO2 emissions of a building.•Type and quantity of off-site green hydrogen influence reduction in CO2 emissions.
AbstractModularization is a method of enhancing project value by exporting a portion of the site work to fabrication/assembly shops or yards. However, the construction industry has difficulties in ...identifying the optimum extent of modularization to maximize its benefits. Research Team 283 of the Construction Industry Institute (CII) developed a business case process to identify the optimum proportion of work hours to be shifted off-site by means of a module scope and identified modularization drivers. With the assistance of the CII’s Modularization Community of Practice (MCOP), this study developed a model that provides the practitioner with specific savings in addition to finding the optimum level of work hours to be moved off-site. The researchers also collected existing business case analysis models/tools from various companies and the available literature to identify the most acceptable or best-fitting elements. These elements were integrated into the new model, which was reviewed and validated by CII MCOP. This model will be applicable to various projects where decision making for modularization is difficult because of the absence of an assigned cost/factor/productivity for different parts of a module job. This research will add to the already-existing literature and research on modular decision-making practices.
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