How to take off quantities from BIM (with the best results)

Taking off quantities from BIM is not as hard as it used to be. With a plethora of tools out there providing the service, it should be easy.

So why aren’t we all doing it? The answer is usually twofold:

1. We don’t have a BIM model
2. We don’t trust the results

The construction industry is fast embracing BIM, with 12% more companies using BIM year-on-year. So we can’t afford to be left behind. Whether we use BIM models now for our cost estimation or not, it’s soon going to be inevitable. So let’s get prepared.

Trusting the results is a more complicated story. It’s true that many quantity takeoff (QTO) tools don’t measure the right dimensions. With tools that don't do the job well, quantity surveyors risk duplicating their efforts and still rely on 2D drawings.

In this post, we’ll explain:

• Why QTO from BIM is important
• How to take off quantities from BIM to get the best results
• 5 suggestions for moving forward

Why is anyone taking off quantities from BIM?

In construction, taking off quantities refers to the process of identifying elements of construction works that can be measured and priced. It’s the first step in estimating the cost of your proposed construction project. 

Almost all construction projects have now been digitalised with the inventions of PDF and CAD. Building Information Modelling (BIM) is the next step. It’s not just a design, or a representation of what you want to build. The key is in the word “Information”. Your BIM model includes information on everything surrounding the project: geospatial information, local data, build sequencing, costs… and much more. Your BIM model can continually be enhanced by multiple stakeholders over the whole life cycle of the project.

Taking off quantities from BIM should be more accurate, easier and faster. That’s why anyone would take off quantities from BIM, as opposed to a 2D model. But many BIM programs are still not up to scratch and require a large amount of manual tweaking. 

BIM software has been stuck in the past and has been preventing professionals from moving with the times. It’s time we started using artificial intelligence to help us achieve the accuracy we need in the limited time we have for construction planning.

How to take off quantities from a BIM model 

It doesn’t matter what state your BIM model is in, as long as it was designed in Autodesk Revit. If not, you’ll need to convert it into an Industry Foundation Classes (IFC) file before you start taking off quantities from BIM.

Step 1: Uploading the BIM model

Either you can use Kreo’s Revit plug-in or you can directly upload your .bim file(s) into Kreo. Kreo Takeoff federates your model for you - no need to worry about having a different model for architectural, structural or MEP. Start getting used to working from one model to avoid mistakes.

Step 2: Fix your model

Kreo checks your federated model and identifies where there are major errors. It will spot, for example, where there is a giant column or wall that needs to be split into buildable sections. It will make recommendations for you to ensure the model is correct. Not your job? Don’t worry, it’s easy. Kreo fixes some issues for you straight away. You can also tell Kreo to ignore the problems you know won’t be crucial to taking off quantities correctly.

Step 3: Classifying the BIM elements

Let artificial intelligence identify and classify the BIM elements in your model. Then you can manually tweak anything the machine is unsure of. Every time you use it and feed the machine with information, you improve its knowledge. Eventually it will understand every model you build.

Step 4: Take off quantities from BIM!

This is the fun bit. Kreo takes off all the quantities for you from the BIM model. You can sit back and watch! 

Step 5: Export for your bills of quantities

Share your model and results with anyone, as Kreo is cloud-based. You can export your QTO into Excel spreadsheets for further analysis in other programs, or to create your bills of quantities faster. You can keep uploading BIM models with design changes as you go along. Keep your records in one place with Kreo. Control permissions for your company or external project stakeholders with advanced permission settings.

2 Tips and reminders for taking off quantities from BIM

Be brave! You’ll get cynics who don’t like to try new technology. But how can anyone know what it does if they don’t try it out? Push for the extra support and see what you find. 

Perfection is the enemy of good. Those who worry this won’t get 100% accurate results should take a long hard look at current practices. Experts who use 2D drawings may be accurate if they have enough time. But in the pre-tender window, it’s usually rushed and vague estimates are used where accuracy could have been strived for. BIM tools were created and are maintained by humans. Feed back when you notice there are mistakes and help tech companies improve. Revit’s QTO tool was good enough until Kreo discovered a better way of taking off quantities from BIM. And we can keep getting better.

Quantity takeoff will improve

Quantity takeoff in construction is still far too laborious. In our survey with Construction Manager Magazine, 63% of professionals said QTO would be the first pre-construction process they’d automate.

By using artificial intelligence to take off quantities from BIM, we’ll see faster, more accurate results. We’ll see quantity surveyors and cost experts spending their time more wisely on value engineering decisions. We’ll see more effort go into the pre-construction planning phase and projects will be predicted more accurately. Construction productivity and quality will increase.

See for yourself

If you’re ready to start taking off quantities from BIM, you can get a free 14-day trial of Kreo Takeoff today. Watch the demonstration video below to see how quick and easy it is. Time to take off!