Building information modelling (BIM) usually counted as one of the main innovations in the field of Architecture, Engineering, Construction (AEC). It works to upgrade the effectiveness of any project from ground zero to post construction maintenance (Ding, L., Zhou, Y. and Akinci, B 2014). However Interestingly in UK around 90 Percent construction company is SMEs, and which holds 3.5 percent share of the market (Harty, J., Kouider, T. and Paterson, G. 2016). Before merging BIM into SMEs, we must understand the what SMEs is and how much impact of SMEs has in construction industry.
Basically, we understand that any company that has less than 250 employees and either a turnover of up to 50 million euro is considered as SME company. Hence in this report we will be discussing BIM application and other dimensions of BIM. In first two sections nD modelling and 4D BIM will be discussed where we will be discussing 5D BIM and 6D BIM in third and fourth section subsequently. Finally we will be giving brief description on clash detection.
‘nD’ represents different dimensions which helps to elaborate information in terms of its’ degree (Motawa I and Almarshad A 2013). An ‘nD’ model is usually considered as part of BIM so that any sort of design adjustment can be made at any level of the lifespan of an infrastructure (A. Lee et al 2005). In ‘nD’ modelling n is any real number which mean n times design views can be taken as input. When we say design views that means it incorporated the works required in different construction phases such as scheduling, cost estimation, maintenance, clash detection etc.
There is different opinion among researchers about ‘nD’ modelling, few defines this as extensive part of BIM (A.Lee et al 2005) where others have tried to separate from BIM ( Succar, B. 2009) but most researchers have agreed that BIM represents the utilisation of nD model where simulation of different phases of construction starting from planning to operation. Moreover, we need to understand that how does this nD works here. In infrastructure development such as residential to commercial, everywhere BIM is essential to implement. So, in this industry we understand any 3D model works as geometry model where 4D model is used for scheduling and 5D for cost estimation. It is also noticeable that anything greater 5D such as 6D or 7D, there is different thoughts among researcher what 6D stands for or 7D stands for (F.H. Abanda, B. Kamsu-Foguem and J.H.M. Tah 2017). Therefore, 6D stands for either facilities management information or sustainability information (Bryde, D., Broquetas, M. and Volm, J. M. 2013). On the other hand, 7D stands for sustainable assessment in design process where this is considered as new cultural design approach to sustainable architecture (Marta Andreani et al. 2019). However, it may work vies verses for example 6D stands for sustainability and 7D stands for facilities management. Basically ‘nD’ model allows stakeholders to have necessary information related to projects at any condition and permits them to input necessary inputs during whole project cycle. Hence this is very interactive system to work on (Ding, L., Zhou, Y. and Akinci, B. 2014).
In this section time dimension, which means scheduling is considered to add with 3D model. To elaborate, in 3D model there is three attributes such as x,y,z and this addition of time dimension makes it look like four attributes i.e. x,y,z,t which is called 4D (Balakina Anastasiya, Simankina Tatyana and Lukinov Vitaly 2018). This schedule of quantities is basically list of materials required on a project. This addition to BIM helps stakeholders to visualise the activities related to the project’s life cycle. The usage of 4D BIM gives the base line for future prospect like 5D or 6D BIM. So, the main purpose of find out the schedules of any project is to find out the cost estimation and procurement.
Fig 1: 4D BIM PROCESS
There are different ways of doing 4D BIM. One is traditional way of doing scheduling another is model driven. For example, if we do schedule of the project by using external software, then we will have to export the file in xls format and use the data source type of time liner to add that information as a csv file. After adding file, in the name column we can choose task hierarchy. Moreover, to accomplish 4D simulation we will have to use search and select sets from attach column to group elements that belongs to same task. Besides, we will need to define sets not only by elements but also by level as construction is taken place by levels. After that we will link these sets of elements directly to the tasks which they belong and for that we will right click in the attach column and choose attach selection set and navigate to the file hierarchy to file sets. For each task we need to define phase type, there are three predefine activity type such as construction, demolition and temporary. We can create our own phases besides these three phases. So, this is one option, another option is if we do not have schedule that is done earlier then we will have to put manually start and end date of the different tasks related to the projects. To do that we will auto attach 3D model and task items will use auto attach tool as well and doing so we can create sequences of works. To create task manually we must go to TimeLiner and click on tasks. By clicking add task icon we can set out activity as name and type of foundation. Then in cells we can set up start date and end date. TO set up the dates we can use fill down command and repeat this for all tasks. Besides under task type we can select different phases like construct or demolish. Once this scheduling and 3D model attachment is done in Navisworks, we can visualise, monitor and control. To configure we can choose different colour like red, yellow and purple according to phase type. For example, red colour is for construct. AT the end we can select simulate to run the whole activities.
5D BIM adds information to the model which carries cost of the project. The utilisation of this addition is to investigate cost and budget of the project. It is used for more accurate and precise estimation as well as any changes in volume and materials, equipment or labour. As 5D BIM consist of 3D+4D BIM, it permits its users to picturised whole activities and cost related to those activities with the passage of time (Balakina Anastasiya, Simankina Tatyana and Lukinov Vitaly 2018). The significance of cost estimation is crucial in the starting of any projects as it decides the project methodology (S. Perera, I. Watson 1998). So, keeping in mind the importance of cost estimation, it is also acknowledgeable that in early stage of any project, cost estimation is not easy task. There is always information gap which can be overcome by implementing 5D BIM to the project.
Fig 2: 5D BIM PROCESS
To implement 5D BIM we need 3D model of our desired project it can be done in Revit or ArchiCAD. Here we are considering Revit. To procced further we need to bring 3D model and fit it to any 5D BIM software such as CostX. Before importing 3D model, we need to convert files. In CostX IFC file supports which is globally recognised. Once we are done with uploading model, we can navigate into the model ins and out. after navigating properly, we can have a look into model properties for any parts where we can find category, family name and type name of that object as well the dimension. We can do this in another way which is isolating objects by category or family name or type name. same thing we can do it from model tree. After isolating any specific object from model, we can get component schedule by clicking schedule. After that we must choose quantity workbooks or templates and there are different ways of doing this. We can import automatic quantities by using BIM template and this mainly work for dwf or dwfx revit file. Hence selecting Revit general file which is most common one and CostX will run through the model and automatically extract the quantities. These quantities will appear in dimension group. Another way of getting quantities is model map function. This allows us to choose what specific quantities will be exported. To create model map, we must model map under dimension group and choose our desired object. Once this model mapping done, we can get four things such as model tree, filtered model view, schedule and mapping definition tab where we can define more precise work, adding level and sub folder if we want. Moreover, we can import the dimension by using the model map that is created and have our dimension group. In addition to we can quantities by object-based dimension group, this will create specific take off which is like the model map function. Once we get our quantities, we can add rates and complete the costing view. For adding rates, we can do it in two ways like we can link with live library rate and by doing so we can see the source of the rates any time. Second method is just to input rate manually. So, after multiplying the rates and quantities we can get the total cost. Finally, we can publish CostX report where we can find the cost estimation of any project.
Any development that is taken place for the present without compromising the resources for the future generations’ need is considered as sustainable development. Sustainable development has three aspects social, environmental and economic. As now a day’s sustainability is so important for infrastructure development, BIM plays an important role in this area. 6D BIM helps to evaluate carbon footprint across the full life cycle of that product such as building or any infrastructure. In AEC industry it is a bit complicated to do the life cycle assessment by finding out carbon footprints because of having varieties of materials and manufacturers (Yang, X.; Hu, M.; Wu, J.; Zhao, B. 2018).
6D BIM is a process that starts with 3D modelling Revit, 4D BIM, which is time or scheduling in NAVISWORKS, 5D BIM which is cost estimation in CostX and finally carbon footprint assessment and analysis in Revit.
Fig 3: 6D BIM PROCESS
In 6D BIM once we have 3D model, we will do the quantity take off from the model by using Revit. To do that we will go to Menu>EXPORT>REPORT> SCHEDULE and will take out the schedule. we have this file as .txt file. Then we must open this file as excel file. Once we extract the quantities, we will also get the volume for the materials. In terms of computing embodied energy and CO2 we need to consider three formulas which are Q=ρV, EE = Q × Iee, EE = Q × Iee. Here we can get the Q by multiplying volume of the material and density of the material. Therefore, we can compute the embodied energy and CO2. We must consider different inventory such as material inventory which we can get architecture’s specification, emission inventory which can be obtained from Bath inventory and material density which is available in building construction literature. For energy analysis, we can carry it in Revit and view it on Green Building studio. Energy analysis can be done from Analyse tab. Before running analysis, we need to define thermal properties of the materials and we can do it from edit type option. We also need to check different analytic construction and parameters. Beside we must set the location of the project from energy settings as well as the type of the project such as commercial or residential. We can also choose levels according to our requirement. Then finally we can run the energy analysis. We can compare the results with another alternative.
We need address this as there is another way of taking quantities which is automatic and connect it new measurement rules. As a result, embodied energy and C02 can be computed automatically and get the correspondent chart eventually (Abanda, F. H., Oti, A. H. and Tah, J. H. M. 2017).
Clashes happen when different material colloids over each other at same place and it might any sort of component. BIM is ideal option to sort out these clashes but there is manual way which is very lengthy. Clash detection helps to run the project smoothly and cuts down any sort of human error. If any sort of error is found, it can be solved instantly from off site which is really makes the work easier and convenient. There are four types of clashes Hard clash, Hard conservative, Clearance, Duplicate. In hard clashes components intersects where in clearance two come to closest distance. Hard conservative is one kind of strict hard clash. However, in duplicate similar components are usually found at the same place.
Fig 4: CLASH DETECTION PROCESS
We need to bring models into NAVISWORKS manage. Once we transfer our models, we may difficulties to find the models that are not in right elevation.so we need to adjust models by going units and transform option and fix the origin and rotation. After merging models, we run clash detective and for that we need go to the option clash detective and we must add a test there. If we want, we can name the test as well as we can choose the models and levels for the test. Besides, we can choose test type such as hard test. Once we run the test, we will get the clashes as a list. So, in clash list we will able to see the nature of the clash such as beam or pipe. Moreover, we can assign someone with a note who will investigate it and solve it. Furthermore, we can use appearance profiler which means we can use colour code to define our any specific work such as blue colour for cold water system. So main aim of this clash detection is to sort the clashes before construction or starting the work. As soon as we sort out clashes, we will publish a report and as report format we can choose HTML (tabular) format. Finally, we will get clash report as well as images of clashes in a folder.