Bill Of Quantities Research Articles

Data fusion approach for a digital construction logistics twin

Construction site logistics deals with the transport and storage of materials as part of the execution of a construction project. An important part of construction logistics is informing those who are involved in the project about the current status of the ordered materials. On the one hand, the missing overview of the material inventory on the construction site and incoming deliveries makes efficient daily work planning on the construction site more difficult. On the other hand, unnecessary search and travel times reduce the productive working hours of employees on the construction site. In order to provide a better overview, the information from existing data sources must be linked and visualized in an easily understandable way for all project participants. Therefore, a digital construction logistics twin is proposed in this paper. Here, the challenge lies in the creation of the digital twin. The aim of this paper is to reduce the manual entry and planning effort needed. Therefore, an approach is proposed, which uses the Building Information Model (BIM), information from the technical specifications and bill of quantities as well as catalogue data from the building materials trade. The Building Information Model comprises the three-dimensional building model, information about the building components, the construction schedule (4D BIM) and the planned storage spaces on the constructions site. The catalogue data adds relevant logistic attributes and could also enables guidelines to be checked, e.g., as part of a sustainability certification (e.g., LEED). If the suppliers’ telemetry data were integrated, end-to-end material tracking would even be possible, similar to “track-and-trace” services from parcel service providers for end customers. The provision of all this data via a Building Information Model server as a “single source of truth” increases the transparency of the construction and logistics processes for everyone involved in the project. Also, this information would, for example, favor the use of autonomous means of transport, which reduces the need for manpower for transport on the construction site.

Automatic Classification of Construction Work Codes in Bill of Quantities of National Roadway Based on Text Analysis

The construction work classification code is a crucial index for consistently collecting unit cost data from the bill of quantities (BOQ). Appropriate classification codes assigned to detailed construction work item descriptions are required to verify project cost and for quality control. However, the codification system is complicated and time consuming for estimators to follow. This study proposes a framework to recognize the text of detailed construction work item descriptions in the BOQ and automatically assign the most similar work classification code. The automatic assignment algorithm was designed to score the similarity of the tokenized words in the work item description based on whether they contain the same word. The framework was experimented with using the national roadway BOQ; this BOQ is used for the procurement process in South Korea. It transformed work item descriptions from unstandardized BOQs into standardized data with more than 91.12% accuracy. The results of this study can be used as a prerequisite step for standardizing construction life cycle cost data and the automatic generation of BOQs.

DESAIN CHANGES IN A SHORT DURATION CONSTRUCTION PROJECT WITH COST AND TIME BOUNDARIES: A PROJECT REVIEW

Design changes are inevitable in most projects. In many construction projects they may look not too complicated to be executed in front of computer models. The actual situation turned out to be the other way around. Apart from detailed changes in shop drawings, bill of quantity and specifications, administrative works related to the project are quite considerations. These mounted consequences would be more for short duration projects with government funding executed in the near end book period. The allocated execution period for short duration projects is not usually allowing rapid changes for the unexpected consequences. This paper presents what actually happens inside the project management during the contract change order process.

ВАРИАНТНОЕ ПРОЕКТИРОВАНИЕ ФУНДАМЕНТОВ ПРОМЫШЛЕННЫХ И ОБЩЕСТВЕННЫХ ЗДАНИЙ ДЛЯ РАЗЛИЧНЫХ ГИДРОГЕОЛОГИЧЕСКИХ УСЛОВИЙ

The article considers the various foundation design for different regions of the Russian Federation. The calculation of the pile foundation was carried out taking into account the peculiarities of hydrogeological conditions in these regions for the multifunctional sport complex. The spatial frame modeling was performed using SCAD and Autodesk AutoCAD software packages. According the calculation S-5-30 5 m long with a section of 300x300 mm (by series) piles received for the Republic of Bashkortostan. For the Republic of Tatarstan: piles according to the S-3-30 series, 3 m long, with a section of 300x300 mm. According to the S-6-50 series, 6 m long, with a section of 500x500 mm piles are accepted for the Perm Territory. To define the price of building foundations, a local estimate calculation was composed based on bills of quantities. Based on the presented final price, it can be concluded that different categories of engineering and geological conditions complexity, imply additional activities in areas with more complex hydrogeological conditions. The cost of building the foundation for the Republic of Bashkortostan amounted to 93.711 million rubles, and turned out to be the largest in comparison with other regions, which is associated with a significant increase in the volume of work due to the installation of monolithic reinforced concrete belts. The authors noted, that analysis of engineering and geological conditions of the construction site is the determining factor in the choice of foundation structures for the designed building. The presented methodology allows to carry out a similar industrial and public buildings feasibility study in construction not only in the considered regions but throughout the Russian Federation.

Digital Bill of Quantities - ATool for Checking Building Information Models

Digital Bill of Quantities - ATool for Checking Building Information Models

Planning, scheduling, & allocation of resources for short-span bridge using Primavera P6

The paper states the advantages of web-based Primavera P6 for structural planning and scheduling Bridge building framing the problems and difficulties experienced in the construction schedule and resource availability. Only Bridge Design and Plannings taken for the project consideration. After the detail creation of Bill of Quantities of the proposed bridge. Here the Bridge consists of four spans only. Each Span is of 10.4 m length. Bridge is located at Yellareddy Tank Bund Portion, Nizamabad district (Hyderabad-Medak-Bodhan). The Resource Planning is the creation of Organization Breakdown Schedule (OBS) and Enterprise Project Structure (EPS) of the project and also to create Work Breakdown Schedule (WBS) and to insert the corresponding activities and schedule them on the basis of created calendar and need to level/smoothen the resources and make effective use of them. Organization Breakdown Schedule (OBS) and Enterprise Project Structure (EPS) of the project has been created Work Breakdown Schedule (WBS) and the corresponding activities are created and need to schedule their resources to activities on the basis of created calendar and need to level/smoothen the resources. Resource Scheduling involves the Scheduling of Project and Activity Network Diagram. Resource allocation enables you to allocate equipment, labor, and material expenditures to your timetable. The reports in Primavera P6 may be used to track resource allocation and potential over-allocation of labor resources.

How to Prepare An Estimated Bill of Quantities for a Project? Iraqi House as a Case Study 'Model’

How to Prepare An Estimated Bill of Quantities for a Project? Iraqi House as a Case Study 'Model’

CONSTRUCTION COST CONTROL FOR ROAD PROJECTS IN THE CONTEXT OF MALAYSIAN CONTRACTORS

Cost overrun is a common problem in the construction industry. Cost overrun occurs when the actual cost exceeds the budgeted, estimated, original, or target cost. Implementing cost control is complicated since it must evaluate many things, such as budget, project cash flow, cost performance, and others. In road construction projects, cost overrun is typical even though cost control has been practised. Road construction in Malaysia can be observed to have cost problems, and cost control practised in the industry needs to be improved. This research aims to analyse the present methods of cost control utilised by contractors in road projects and propose possible strategies to improve cost control in enhancing project cost performance. The objectives of this research are to investigate the practices of cost control in road projects by the contractors, to assess the problems encountered, and to suggest possible strategies to overcome the problems. This research employs a quantitative method by conducting a survey questionnaire as an approach to data collection. A total of 160 questionnaires were distributed to G5, G6, and G7 contractors, while only 32 questionnaires were received. However, only 27 respondents were involved in a road project. The data obtained were analysed by using Microsoft Excel. Based on the results, cost control practices in road projects include record keeping, financial reports, valuation of work in progress, work programmes, approximate quantities method, cost control at the site, and daily labour controlling. Next, the problems encountered include obtaining standard data, change of works from variation order, changes of design, instability of material prices, and inaccurate quantity take-off. Lastly, the strategies to overcome the problems include practising effective strategic planning, practising effective site management, providing detailed descriptions of Bill of Quantities (BQ), utilising cost value comparison, and ensuring the cost budget is realistic.

Forecasting Labour Cost of Construction Trades for Two-Storey Houses: A Single Rate-Based Approach

With the labour cost contribution of 30%- 50% to the total construction cost of a typical building, construction is recognized as a labour-intensive industry. The extant literature evidenced that there exists labour scarcity in many construction trades, which has caused several negative effects. Hence, the assessment of labour requirements prior to the commencement of the building construction would help to mitigate the effects due to labour shortages at the organization and project level. This research aimed to assess the labour requirements for the cost significant trades of two-storey houses in Sri Lanka. The study involved a survey of thirty-eight (38) two-storey houses to collect the required data. The required data were extracted from the Bill of Quantities (BoQs) of those 38 buildings and assessed based on the norms available in the building schedule of rates (BSRs) practised by the key construction companies. The analysis identified that the finishes, in situ concrete works, doors and windows, services, masonry works, and roof works are the significant trades, respectively in the descending order of their contribution to the total cost. However, in the descending order of their labour requirements, finishing works, masonry works, concrete works, reinforcement, formwork and roofing work are more labour-based activities, require 0.274 skilled labour days and 0.228 unskilled labour days, on average for the construction of per unit (sq.ft) of gross floor area (GFA) of a two-storey house in Sri Lanka. Further, in the case of two-storey houses, cost significant trades contribute to around 19% of its total cost. This would enable estimating the labour cost for a proposed project and thereby implement appropriate strategies to manage the labour shortages in projects and the construction industry as a whole.

Application of BIM in Tunnel Design with Compaction Pile Reinforced Foundation Carrying Carbon Assessment Based on Advanced Dynamo Visual Programming: A Case Study in China

Carbon emission assessment in civil engineering has gained worldwide attention due to the negative effects of greenhouse gases on the environment. Significant amounts of building materials and electric power are consumed during the construction of tunnels, causing the release of greenhouse gases into the atmosphere. In addition, building information modeling (BIM) can be utilized to realize the computerized design of tunnels, and improve construction efficiency. However, the traditional BIM software (Autodesk Revit) lacks tunnel components and is unable to directly create a three-dimensional tunnel axis. This paper adopted BIM to build a three-dimensional model of the tunnel components for tunnel and carried out batch parameterization and component lofting based on Dynamo visual programming. The BIM of the tunnel guided the construction procedures and improved the construction efficiency. Based on the emission coefficient method, we calculated the carbon emissions from each component and loaded them into the BIM during the parameterization process. After the tunnel modeling design was completed, a bill of quantities was obtained. Then, the carbon emissions from the whole tunnel construction were calculated according to the bill. Thus, the combination of BIM technology and tunnel engineering was realized; this has practical significance for reductions in emissions, and cleaner construction in relation to tunnel engineering.

Assessing material and embodied flows related to building services in office buildings — the case of Brussels, Belgium

An increasing number of cities and regions are promoting reuse as a key strategy in the transition towards a more circular economy in the construction sector. However, the reuse supply chains for building services are currently underdeveloped in most cities and regions. There is a need for a better understanding of the material flows at the city and regional levels. This study describes a bottom-up approach to quantify material flows related to building services as well as their embodied environmental and economic flows. It relies on the selection of a minimum of 1 new construction or renovation project representing material inflows and 1 demolition or renovation project representing material outflows. Actual products from bill of quantities and pre-demolition audits are mapped against a list of 234 archetypes, and archetypal inflows and outflows are extrapolated to the city or regional level. This model is applied to all office buildings in the Region of Brussels, Belgium. Results show that rectangular ductwork is responsible for almost 30% of annual inflows of building services, which amount to 32 km/year, 1,6 kt/year, require 96 thousand m3 of freshwater/year, 131 TJ of primary energy/year, emit 9,9 kt CO2 eq/year, cost 3;4 MEUR/year to project developers, and whose installation in buildings represents 51 khours/year. In addition, results show that the outflows of black steel pipes, recessed luminaires and electrical cables exceed the inflows on an annual basis, suggesting that there is significant potential for covering needs through the reuse of those products.

Västlänken – The West Link Project, Korsvägen construction section in Gothenburg, Sweden

AbstractWest Link (Swedish: Västlänken) is one of the biggest infrastructure projects in Sweden building an in total 8 km double‐track railway tunnel in Gothenburg, which is currently under construction. “E05 Korsvägen” is a construction lot which is part of the West Link project with the Swedish transport authority Trafikverket as the client. The works were awarded to the Joint Venture (JV) West Link Contractors consisting of Wayss & Freytag Ingenieurbau AG and NCC. A special contract model with a design and build part combined with a regular bill of quantities comprises building an underground double‐track railway tunnel with a length of 3.2 km and the new Korsvägen station. This sub‐project includes three drill and blast sections and three open excavation sections. All three construction pits will be executed in challenging soft ground conditions. The JV is confronted with high environmental demands and special requirements for the blasting works in the urban area of Gothenburg.

Reducing Life Cycle Embodied Energy of Residential Buildings: Importance of Building and Material Service Life

Energy use in the building sector is considered among major contributors of greenhouse gas emissions and related environmental impacts. While striving to reduce the energy consumption from this sector, it is important to avoid burden shifting from one building life cycle stage to another; thus, this requires a good understanding of the energy consumption across the building life cycle. The literature shows greater emphasis on operational energy reduction but less on embodied energy, although both have a clear impact on the building’s footprint and associated environmental impact. In previous studies the importance these energy aspects have been presented; however, the critical role of embodied energy linked to the replacement of materials over a building’s life is not well documented. Therefore, there is a knowledge gap in the available the literature about the ways to reduce the embodied energy requirements of buildings over their useful life. Service life of buildings and their constituent materials may play an important role in this regard. However, their potential role in this respect have not been explored in the previous research. This study critically addresses the above-mentioned gaps in the literature by investigating the combined effect of building and material service life on life cycle embodied energy requirements of residential buildings. Life cycle embodied energy of a case study house for an assessment period of 150 years was calculated based on minimum, average and maximum material service life values for the building service life of 50, 100 and 150 years. A comprehensive input–output hybrid analysis based on the bill of quantities was used for the embodied energy assessment of the initial and recurrent embodied energy calculation for each scenario. The combined effect of building and material service life variations was shown to result in a reduction in the life cycle embodied energy demand in the order of up to 61%. This provides quantifiable and verifiable data that shows the importance of building and material service life considerations in designing, constructing, and managing the buildings in efforts to reduce energy consumption by buildings. A secondary contribution of this paper is a detailed sensitivity analysis which was carried out by varying the material service life values of each building material and the embodied energies for each new scenario was recalculated for two assessment periods. The findings show that, for each material service life variation, the LCEE increases as BSL increases for a 50-year assessment period, but the LCEE decreases for a 150-year assessment period.

Systematic review on the integration of building information modelling and prefabrication construction for low-carbon building delivery

ABSTRACT Reducing emissions from construction and buildings is pivotal to climate change mitigation. Hence, transitioning to a low-carbon emission industry is the focus of many countries by applying prefabrication and building information modelling (BIM). Although prefabrication and BIM contribute towards reducing emissions, the burgeoning body of knowledge mostly consider them separate and often neglect advances in their synergies towards low-carbon building delivery. More importantly, a thorough review of the current state of BIM and prefabrication integration is still lacking. Therefore, this study uses the systematic review to explore the integration of BIM and prefabrication towards low-carbon efforts in building delivery. Six typologies of integrating BIM and prefabrication for low-carbon activities were revealed. Thus, energy and environmental assessments; visualization and real-time monitoring; parametric design optimization; automation in modelling; BIM-PC modifications; and information mapping. Further, these typologies explored four main low-carbon attributes in building delivery; energy evaluation, material selection, waste reduction and process efficiency. From the findings, research gaps were identified and future research directions such as BIM-based bill of quantities for carbon footprint analysis, and circularity features of prefabricated components were provided. This study consolidates advances in BIM and prefabrication scholarship and informs practice for evaluation of low-carbon processes in buildings.

Decision criteria and intelligent decision method for tunnel excavation scheme selection considering carbon emissions

The tunnel construction process is accompanied by high resource consumption and non-negligible greenhouse gas emissions. Reducing the carbon emissions from this process is an issue that should be considered in the decision-making stage. For tunnel construction using the drill-and-blast process, selecting a reasonable excavation scheme is a feasible method for reducing carbon emissions. This paper proposes an evaluation index system that takes into account the stability of the tunnel construction process and the reasonable assessment of carbon emission levels. For various scenarios with different focus on stability requirements, theoretical deductions are used to filter out the key indicators that should be used as assessment items. For the determination of carbon emission assessment indicators, this study is guided by the life cycle theory, and in the determined calculation boundary, the reference of previous projects and expert opinions are selected as the item source to fill the unfavorable situation in which the carbon emissions of different excavation schemes cannot be accurately calculated because of the lack of bills of quantities in the engineering decision stage. This paper also proposes an intelligent decision method based on a support vector machine to better complete the task of calculating and ranking the utility of excavation schemes to adapt the proposed multi-factor parallel evaluation system. Finally, the proposed decision indicator system and decision method were applied to the selection of the excavation scheme in an engineering case, and reasonable and realistic scoring results were obtained.

Scan-to-BIM technique in building maintenance projects: practicing quantity take-off

PurposeIn Hong Kong, over 20,000 private residential buildings will be 50 plus years old by 2039. However, building maintenance has not been owners’ popular interest because of the high cost as well as the complexities in justifying whether the quantities and prices of the maintenance works are reasonable. This paper therefore aims to validate the practicality of adopting Scan-to-BIM: Terrestrial Laser Scan (TLS) and Building Information Modelling (BIM) to perform quantity take-offs (QTO) for estimating building maintenance costs.Design/methodology/approachA 64-year-old tenement building was selected to conduct a case study. In this instance, the building had undergone a Scan-to-BIM survey approach to generate QTO for the bills of quantities for external painting works. The Scan-to-BIM approach includes site visit, positioning of scanning equipment, assignment of circular scan routes, point cloud registration and identification of residual error. After that, time, cost and quality data were logged into contrast with QTO on as-built plans for external wall plastering works.FindingsThe “time”, “cost” and “quality” of the Scan-to BIM practice were then examined and compared with the prevailing practices of manual measurements on as-built drawings. As noted from the results, the initial cost of Scan-to BIM is high, owing to the cost of equipment, software and capable available operators. However, the authors identified that the time and cost can be significantly minimised by developing and implementing efficient practices such as preparing a detailed scan plan, equipping modeller with quantity surveying knowledge, using automated object recognition and 5D BIM software packages such as Vico Office and CostX.Practical implicationsThe upshot is that Scan-to-BIM could be one of the measures to advance the clarity in the QTO and estimated price of the maintenance projects.Originality/valueThe practicability of Scan-to-BIM has received limited attention on existing building maintenance project. The Scan-to-BIM approach was examined using a case building of a 64-year-old tenement building. The approach demonstrated in this research study is promised to advance the clarity in the QTO and estimated price of maintenance project.

Research on Construction of Bill of Quantities of Prefabricated Buildings Based on BIM

Building Information Model (BIM) Technology can be widely used in various construction fields. The construction quality and project cost of the prefabricated construction industry based on BIM can be effectively controlled. Based on BIM Technology, the integration of bill of quantities can effectively control the cost of prefabricated construction and improve competitiveness in the bidding process. Based on this, the characteristics and advantages of bill of quantities pricing based on BIM were expounded in this paper. Besides, the structure and content construction of bill of quantities were analyzed, followed by an analysis of pricing control strategy based on BIM were analyzed for assembly building quantities for reference.

The Causes Influencing the Occurrence of Variation Orders in the Construction of Buildings

In the construction of buildings usually, problems occur because of the causes of change orders. The main causer of change orders is the owners, consultants, and contractors. These changes lead to conflicts among them which result in influencing building projects. Therefore, it is necessary to analyze the causes of change orders to reduce them and facilitate management. This paper determines the most critical factors that cause change orders from a different point of view, a consulting owner and a contractor, and a study of the reality of the management of change orders when constructing public buildings. The method employed in this research is a field survey using interviews with experts working in the construction of public buildings. Furthermore, the questionnaire was distributed manually and electronically. In conclusion, it would appear that the causes of change orders have been hierarchically according to the viewpoint of the owner, contractor, and consultant. The analysis leads to the following conclusions: Agreement of viewpoints owners, contractors, and consultants on the critical causes of variation orders were: ( the difficult financial situation - change material specifications to benefit the project - technical necessity - the nature of the site). Moreover, the point of view (owners and contractors) on the essential factors that cause change orders were: (preparing a bill of quantities is inaccurate - weak consultant guess ). In contrast, the consultant's point of view differs, as he considers these causes ineffective. It can be interpreted that the consultant sees these factors as insignificant because of his duty to implement the bill of quantities and designs. This research paper concludes that a complex causal relationship exists between the causes of change orders. The relative importance index (RII) for variation order causes varies among different groups' viewpoints (owners, contractors, and consultants).

Digital Twin Aided Sustainability Assessment of Modern Light Rail Infrastructures

This study aims to evaluate the whole life cycle performance of Precast Advanced Track (PCAT) light rail systems in a digital twin environment, which is time-saving, flexible, and highly accurate. Two sustainability aspects of the system are addressed: environmental and economic impacts. In the life cycle assessment (LCA), energy consumption and CO2 emissions are calculated, whereas costs at each stage were calculated and converted to present values in the life cycle costing assessment (LCC). Revit is used for assessment. It enables the bill of quantities in the models to provide quantitative data for sustainability assessments. In the PCAT light rail systems, all structures and components have been considered, including subbase, concrete slab, rail fastening, rails, bituminous layer, rubber pad, and grease lubrication. Results exhibit that concrete slabs for street and off-street systems have a minor contribution to minimizing energy consumption, CO2 emissions, and costs. Rail fastenings and rails can be recycled, but the energy consumption is relatively enormous. Unrecyclable materials such as bitumen and grout account for a large portion of lifecycle CO2 emissions and costs. Surprisingly, these two materials are quite sensitive to parametric change. Accordingly, the digital twin confirms that PCAT concrete slabs demonstrate a good performance throughout the whole life cycle. However, there is still room for improvements, for example, re-designing a concrete slab with less grout while showing good waterproof performance. These structural modifications can be updated on the digital twin to enact positive changes for the sustainable development of light rail systems.

Evaluation of price distribution of building elements in the Bills of Quantities of Locally Owned Construction Firms in South West Nigeria

It is important to diagnose locally owned construction firms (LOCOFs) cash flow and hence their financial health through assessment of percentage cost allocation to various work items in the bills of quantities of new building projects. To this end, this paper analysed locally owned construction firms’ priced bill of quantities (BOQ) of awarded building projects in order to demonstrate the appropriateness of their cash flow management plan and techniques. This is with an aim of improving the performance of local firms. Sixty BOQ of new building projects awarded to various LOCOFs in year 2007 to 2015 were assessed. Cost allocated to major early and finishing building element work stages were identified, analysed and relevant inferences bothering on firms’ financial plan and cash flow management techniques were discussed. The result showed that average percentage cost allocations for building preliminaries, substructure, frame structure, roof and finishes arranged in descending order had the highest cost allocation to building substructure (20.35%), finishes (12.98%), frame structure (12.31%), roof (12.08%) and preliminaries (2.85%). Also, 24 of the 60 BOQ had more than 50% of the contract sum allocated to building projects elements’ early stages of work. This cash receipt and payment early advantage can be well utilised by applying a well thought out cash flow management plan and technique that will boost LOCOFs’ working capital.