iTWO costX® Consultant Series: BIM Revisioning

For our latest Consultant blog series, we’ll be delving deeper into the topic of 5D Building Information Modelling to provide some handy tips and tricks for iTWO costX® users. Our third post is from our US based Consultant Ben Baker, who has provided an overview of how to use the Auto-revisioning tool within iTWO costX® on BIM files.

The ability to revise models plays a significant role in the construction process. When a model is designed well, and the properties of each object are consistent, the revisioning process will go smoothly. If something has been added, it can take a little more time to fish out the changes; however, with iTWO costX Revisioning, that process can be greatly optimised.

In this blog, I’ll show you a BIM file that I used a Model Map on to complete the takeoff, and focus on the exterior doors and the wood deck. We’ll see how the revision process will show you the changes and an overlay comparison of the model so you can identify the new quantities quickly and efficiently.

The two exterior doors and deck are highlighted green in the above image. These are the items we’ll be looking at today. When you have received a new Model and want to revise your current one, you need to go to the Revision Tab and press Add near the top left side of the screen.

This will prompt you to give your revision a Name and apply any notes if you want to keep a paper trail. You will also have the ability to change the default Drawing Path if needed (but typically this won’t need amending).

Once you have created your Revision Name, click Insert. The model and any drawings will be locked with a padlock symbol. You will now need to Promote your Model by using the Promote Drawing button.

Once you click on the Promote Drawing button, it will ask you what you want to do. There are two options at this point: Choose a New Drawing File or, Keep the Same Drawing File

If you’re choosing to bring in a new drawing, you’ll have to find where your revised or updated BIM file is. I’m using a DWFX File with drawing sheets attached to it in this example. If you need to update your sheets, select the sheets you wish to promote; if it’s only the Model, then select only your Model.

The drawing properties window will appear after it’s been loaded, and nothing should have changed unless you want to change the actual model name and its folder structure. Clicking Update will bring up another pop-up informing you that your BIM Dimensions have not been promoted yet, and to use the Promote BIM Dimensions button to update them. Press OK and find the Promote BIM Dimensions button within the Revisions Tab.

Once that process is completed, iTWO costX will inform you that changed and deleted BIM dimensions have been automatically revised and to re-use the original methodology that you extracted the quantities with on the original takeoff (either a template or Model Map). You also, at this point, have the option to perform manual takeoff with the objects of the model if required.

Let’s look at the Deck and the two Exterior doors we saw before the revision.

The Deck is still highlighted in Green, and the SF footage quantity has been updated to the new size. However, the two doors are now showing as a 0 count, and we’ll need to use the Model Map to account for those new doors. Let us compare the drawings now to see those changes. Find the Compare Drawings button in the revision tab.

This option will ask you a few questions. The first is which Revision you want to compare. If you have multiple revisions, you can compare the newest model to any previous model. The Comparison Method must also be selected, and the best option here depends on what you’re revising. In this case, I am using the Match Objects.

When you match objects, the original or revised model will be compared to the one you choose.

When you press the Layers tab, you’ll get five options.

You can see the changes, what is new, deleted, or see how something is different before and after. You’ll quickly know what you need to address or capture by doing this.

Once you’ve compared your two models together and seen the differences, you can then run your Model Map once more and add any additional items that may have been added. It is important to note that if there are objects in the Model that are not captured in your Model Mapping definitions, you’ll need to map those definitions to capture them within your format.

Once the dimensions are updated, the estimating spreadsheet can be updated with the new quantities and therefore, the updated price.

Lastly, there is an option to view a BIM object log that will cycle through all the objects and tell you if the objects have been used more than once, if anything is duplicated, and if there are any unused objects. This log will help you vet your work and see if there is anything that needs to be verified or picked up.

Duplicates, in this case, are shown if there is more than one quantity pulled out of one object. These Railings show two items: a 3’ Pipe and a 900mm Pipe. This would be a double-up as the 900mm pipe was taken off before creating the model map and pulling out the 3’ pipe.

However, the curtain walls show a duplicate for the window blinds and the exterior curtain wall system.

I used the curtain wall objects in the model and supplemented the window blind takeoff.

Overall, BIM Revisioning is an important process that aids iTWO costX users in providing fast feedback to architects and designers about any changes in the model. If you’d like to learn more about BIM Revisioning, please watch our iTWO costX Coffee Break video here.