The Drafting Side of Building Information Modelling

1. Overview

The Building Information Modelling (BIM) sector has experienced a rapid surge in growth, accompanied by many exciting new developments. However, this rapid expansion brings not only opportunities but also new challenges. While there are numerous explanations on how to successfully execute projects within the BIM environment, the role of the drafting side in these explanations is often lacking. So, this article will highlight some of these challenges on the drafting side of the BIM industry, how to address them, as well as methods and tips to plan, start, and successfully execute projects.

1.1 What Is Building Information Modelling

BIM is an intelligent 3D to 6D model-based process that gives architecture, engineering, and construction professionals the insight and tools to plan, design, construct and manage buildings and infrastructure more efficiently.

BIM remains a powerful tool even if you don’t aim to move to the harder-to-reach 6D. However, working up to 5D will already assist both your company and clients in better understanding how projects are executed and managed. Working with BIM is an opportunity for the engineer/contractor to enhance open and transparent communication with the client about their projects.

Let’s first understand the various levels of BIM.

2. Building Information Modelling: 2D to 5D Explanation in a Draughting Situation

2.1 2D

Traditionally, all modelling was done manually in 2D. In fact, despite the incredible advances made in computer and drafting software capabilities, some companies still exclusively use 2D. Of course, some drawings still need to be done in 2D, e.g. process planning, plant layouts, etc.

However, modelling only in 2D does not cut it anymore, and to stay relevant, any serious design office needs to upgrade its drafting capabilities to 3D at least.

2.2 3D – Sized Components

At this step, you start incorporating the intelligent modelling side of BIM. Here, you can stop using extrusions as model placeholders and use actual-sized and shaped components. This means structural beams, piping, etc., will have accurate sizes, weights, and specifications from your most often-used design codes.

You can extract the full Bill of Materials/ Bill of Quantity/ Material Take-off/ Material Take-outs for these components from these models.

If you utilize your programs correctly, you can create 2D design drawings from your 3D models, which are linked to each other. So, updating the 3D models automatically updates your 2D drawings.

2.3 4D – Project Schedule

Here, things get interesting and fun. 4D BIM Modelling incorporates the project schedule.

After all the hard work to set up the 3D modelling, Project Planners need to change the schedule multiple times to accommodate all the subsequent changes made to the 3D model.

With 4D BIM Modelling, you combine that 3D model with the Schedule in one program. Now, you can simulate your construction projects to accurately predict whether your schedule works smoothly or if the changes result in clashes.

During execution, as the schedule is updated, the drafting office can verify that the 3D model still correlates to the updated schedule.

2.4 5D – Project Cost

5D BIM modelling takes 4D and adds Project Cost.

When you have successfully integrated your 3D model and 4D Schedule, you can start adding your costs, taking your model up to a 5D level. This means you will be able to immediately determine how much any clash/ delay/ change will cost and the impact on the overall CAPEX of the project.

This allows for quick, efficient, modern decision-making tools to address any proposed changes. The full scale and impact of any changes can be modelled before large amounts of money and time are spent.

Building Information Modelling (BIM)

Small CMS Station 5D Screenshot – showing a model integrated with cost and schedule

2.5 Building Information Modelling BIM from a Drafting Perspective

There are various explanations of BIM, but none of them directly address the Drawing office side of this technology, only the theory. Most people, therefore, fail to understand the entire concept, resulting in mistakes. If the drawing programs are not set up correctly, they won’t be used to their full capacity. This is the main reason why most people give up after developing BIM systems.

There might be BIM specialists out there who know the systems’ theory, but so many forget the information they will use in the 3D model when they start moving into 4D and 5D. Yes, the drawing office is just as important to this system as the technology and theory.

The specific drawing programme, or technology, does not matter so much. There are various, and they are all good with their pros and cons. The concept stays the same all the way to level 5D.

Design Drafting Staff have a streamlined way of designing and modelling, and this will have to be adjusted slightly to ensure that the models being produced fit the construction/fabrication schedule to ensure seamless integration in your Secondary programme. But knowing how to design gives you the thought process to make quick and intelligent decisions.

Completed Intelligent 3D Model (Navisworks)

3. Advantages of Using Building Information Modelling Systems

3.1 Project Construction Planning

You can use this tool to simulate the construction sequence. You can break it up into sections (Days/hours), so in the morning’s site toolbox meetings, you can show your teams which areas they will be working on. In this way, you can track one program’s actual start and end date.

3.2 In-house Training

Setting up a model in the office can give your employees or fellow draughtsperson a visual idea of what you are trying to teach them. They can keep that file (we use Navisworks Manage) so they can measure and refer to those files. They will be able to see the correct specs and safety distances.

3.3 Client Liaison at Progress Meetings and Interactions

Creating an environment where the client can have real input into their Infrastructure (in our case, Plants/Tank farms, etc.) will enable you to deliver a better end product. This minimizes changes later in the project when most of the work has already been done.

3.4 Cost Prediction in Real-time

When you run the simulations, and construction has started, you can track the costs and actual timelines in one place, using models and updated information. Changing the actual time started will indicate a change in the cost, which you can see immediately.

3.5 On-site Personnel Training in Equipment/Operations

When a large plant can get noisy, it is very difficult to train an operator in those conditions. Using the BIM tools, you can sit in an air-conditioned office and show them exactly where and when they have to be there and spare your time, reducing the risk of someone not understanding. It’s also safer.

3.6 Fabrication/Construction From the Model

Using the 3D model in a program such as Navisworks will enable you to use that as a fabrication method. Using visuals instead of other drawings, which can confuse some, can save time and predict problems. This is a big step forward; the benefits will be great if you can ensure your designs are sound.

4. Preparation

There is quite a lot of preparation to ensure that your company can execute a BIM project. If you realize in the middle that you are not prepared, fixing the projects will be much harder, and the delays will be immense.

4.1 Method Statement

You must sit with your dedicated BIM team and create a method statement for how you will execute your projects. Ensure your team has the same idea and that it is aligned with the results. There are a lot of examples of how to do this, but do not overcomplicate it. When you overcomplicate it, there is a chance that your team will not understand the process, and mistakes will be made.

4.2 Design Criteria

After you have written a Method statement, you will move to the design criteria. This document will assist the drafting staff in knowing the standards to which they should be drawing. This will include 100% correct layer naming, document numbering, details that need to be drawn in, amount of model break-ups, etc.

4.3 Training

Training is one of the most important steps in the process. It is important to train your employees on what to expect and what is expected from them in this journey. You will ask them to work with high quality and concentration to ensure their models are correct for using BIM. Letting them understand the entire purpose of BIM and the excitement about it will give everyone a common goal.

It will not be necessary to send everyone on training for 2 days, but maybe send a few leaders and let them guide and teach the rest of the team. The drawing teams must be educated to understand construction sequences because they must draw 3D models to communicate the idea to fit the schedules.

4.4 Start Small

Start with a smaller project. Have a DEDICATED team that executes a smallish project so all the lessons and gaps can be filtered out. On the smaller jobs, it is easier to fix a mistake and catch up, the larger project gets confusing an overwhelming to everybody. Especially when the whole team is still learning and finding their feet, remember that the timelines on these projects differ from those of normal 3D modelling projects because the attention to smaller details should now be considered.

4.5 Set-up

After creating those two crucial documents (Method Statement and Design Criteria), you are ready to set up your projects (referring to the Drawing office environment). This might be different from what you would have done in other projects. Look at how you will split up your drawings and how you will be drawing them.

Model for Two Pipelines Across a Bridge

5 Building Information Modelling: Tips

Knowing there will be pitfalls and how to avoid them is a crucial part of executing a BIM project successfully, and there are a few if you are not ready or not set up for the time to come.

5.1 Time

The project managers need to be updated on how long these types of projects take. You will learn this if you do a smaller project to test the waters. It is much harder to keep track of the time limit, which is too short, and it involves a large amount of data, which is a new area of expertise.

5.2 Correct Modelling

It is of utmost importance that the team adhere to the Method Statement and the Design criteria. The BIM software will be confusing when the correct layer numbering and naming are not used. Finding items to connect to your simulations will be difficult in a model with many components.

5.3 Research

Do extra research to be sure that you understand the concept correctly. Because there are so many varieties of this process, it can be up to you to take a piece of each puzzle and complete it.

5.4 Discipline Interactions

Part of the purpose of BIM is to start creating a more combined working environment for all disciplines. This will stop the battles between each other. Understanding each other’s role in the end goal can improve productivity. At this stage, integrating the project scheduler and the draftsperson is important so they can start drawing the correct information to suit the schedule.

5.5 Quality Control

Be sure to make provision to quality check your teams work regularly, once again you do not want to realise at the end that something is not up to standard. Be sure that they stick to the design criteria and double-check that the model correlates to the project schedule that has been set up. In a perfect world, the schedule should be done before the modelling starts, but we all know it is not a perfect world…

5.6 Software/Processing speed

Using up-to-date software and computers assists in the process. It can be demotivating to the team to have constant slowness of computers and also slows down the entire process.

Quality assurance example – project set-up in the drafting environment

6. Building Information Modelling: Incorporating PointCloud Data

Incorporating PointCloud data into your BIM is one of the best tools for the Brownfields and even Greenfields sites. An intelligent 3D model can be created from Brownfields As-built Lidar Scans. Scanning is a great tool to assist in clash detections, minimise the risks, and assist with fabrication.

In Greenfields areas, the point cloud can be used for space planning and future expansion planning. What is important to know about this tool is that it can be misunderstood and then misused. Knowing how to use it can improve your productivity and deliver a better end product.

6.1 Quality

The quality of a scan is the first key point in determining the value of the PointCloud data. Although it is a bit more expensive to use, the value it brings is priceless.

It is important to create a rule of thumb for the scanning teams to know how many times around equipment they should be scanned to create the best resolution for modelling. Having experienced scans that were not up to standard, struggling through modelling with them, and losing faith in this technology (my first scanning project), it is difficult to maintain a high standard of modelling.

Next, determine the length of time the scanner should scan at one position. This also improves the quality of the scan. The longer, the better.

The file sizes of these scans can be enormous, so determine if you can use the black-and-white version or if you need the scan-colour version. It seems to assist if it is in colour because the teams can have a better idea of the site since not the entire team can go to the site.

6.2 Processing

After the scanning, the correct processing of the scans must be done. This needs to be done by someone who understands the environment and knows what to look out for when problems occur. The problems might be anything from a few misalignments to the orientation being wrong.

6.3 Time

Enough time must be given for the scans to be completed and processed. If this is not done, you will have unclear scans or the scan misaligns, and inaccurate work will be done. If improper scans are done, more money will be spent to send people to the site to do manual markups (more inaccurate) or send the scanner again (costly).

6.4 Training, Training, Training

No one can be good at anything if they are not trained or at least assisted in the correct direction. Using the PointClouds is a real challenge (take it from me), and training needs to be done. There are intricate ways of dealing with PointCloud. Knowing how to use the PointCloud, the most complex structure/equipment can be modelled from it. Do not lose faith in the technology; if you feel that you are not satisfied with its performance, it might be a flaw in the process. Remember that with correct processes in place and correct scanning, it is a tool to improve productivity and time, not decrease it.

6.5 Storage

The data from PointCloud scans can vary from 40GB to 600GB, 1TB, or even larger. These are massive amounts of data. The PointCloud data is sensitive, and it references a lot of different files. There are ways to ensure those reference files become one.

To store this type of information, you will either need a massive server just for PointCloud data, or you will have to use those combined data sources and add only the piece of the puzzle that the person is working on on their computer. Breaking the PointClouds up into respectable areas seems to work better than everyone working off one set.

6.6 Software/Processing Speed

The same principle applies to working with PointCloud Data in your software than with the Modelling, if not more so. PointCloud uses a lot of processing power to run, so computers that can run this should be strong. With that said, making PointCloud more user-friendly comes with the training thereof. Be smart, work smart.

End Result with Quality Assurance. Now, you can start 4D connections and 5D incorporation.

7. Suggestions

Working with Autodesk products has been accommodating to the PointCloud and BIM environments. They have programs that are just viewers and many designing programs for all disciplines, which work well with Navisworks (also Autodesk). The files import seamlessly into each other.

8. Conclusion

The entire BIM process, including the various technologies, can be intimidating. Still, with proper research, preparation, and some of the tips discussed, it is possible to achieve huge project success using BIM.

Don’t forget about the worker ants (draught personnel). They have to build the nest, and they know the flaws and challenges behind the theoretical methodologies. Keep your entire team updated and in the loop throughout the project, and ensure their opinions and concerns are collected and incorporated. Without the worker ants, there will be no nests.

Remember that the BIM environment allows people to come together and create a more integrated environment.