Today I would like to talk about buggy BIM models. I am not talking about models that look a little janky or are an organizational mess, those are for another days rant, no I am talking about the “Review Warning” button.

At some point in your career you will come across an old project that has a large number of warning messages. Either it was an inexperienced drafter or there was a deadline and the project ran out of money, or it was you and you are trying atone for your BIM sins (I certainly am not without guilt). Either way, you need to get the model aligned with office standards.

What are warnings?

Now there are four types of error messages in Revit: Informative warning, serious warning, critical warning, and fatal error. All four of messages fall into two categories: ignorable or you aren’t doing anything until you fix this.

Informative warning - laissez-faire

This warning typically involves items that have no real impact on your model, such as, you deleted a room, but the room is still remains in the project, or placing an item in a view where that category is turned off by the visibility graphics. Something to be aware of but no real issue.

Serious warning – I can let future me deal with these problems.

These can be anything like a wall overlaps, beams are off axis, or two doors have duplicate “Mark” values. This warning also is an ignorable item but should be reviewed soon to not cause larger errors down the line.

Critical warning – Ok. Fine.

These warnings can be incomplete sketches, incompatible phasing, or a hosted object is no longer cutting the host. These items are in the “stop the presses!” category and require you to deal with them before moving on.

Fatal Error – Crap.

Pray you do not get this error after slaving away for several hours and forgetting to save regularly. Essentially, you did something, and Revit was unable to resolve the change and caused the program to crash. When this happens, Revit brings up a dialog box asking if you want to save a recovery file. Typically, this works and saves you any lost time but when this does happen you should immediately use Revits audit feature.

Reasons to resolve warnings

Realistically, you should be able to work in a model and never have to resolve the any of the “serious warning” messages however unresolved items can cause a couple of issues.

Your model will slow down.

• You do not want to have dead weight floating around in your model, the number of objects you have in you project increases the files size.  

• When you make a change in Revit it references the position and parameters of all other items in the project which can cause your computer to slow down when processing the change. It is especially apparent when you work from a mid-range laptop.

They can contribute to a fatal error.

• All serious warning messages are essentially unresolved conflicts and adding to the list can increase the probability of a fatal error.

How do I resolve these errors?

Revit aggregates a list of informative and serious warnings that can be checked by clicking Manage > Inquiry > Warnings.

Revit categorizes errors and groups the objects in conflict. If you click on the object in the list, the conflicted object gets highlighted in the model. Or, if you click the show button Revit will bring you to a view where the item is visible. It may take a couple of views before the object is apparent.

Sometimes, however, you are unable to clearly see where the item in question is exactly. This is where the “select by ID” button comes in handy. Every single object in Revit gets assigned an ID tag, from lines to infill walls from demoed windows. If you copy the object ID into the “select by ID” search box you will be able to find the object no matter what. This 100% saved my butt once. (Whenever I tried to modify a specific window the model would crash. It was only after I used this feature I found out the window was being hosted by an infill wall which was causing the issue.)

You can also export all errors to an HTML file to copy and paste the ID number directly into the search. (I find that process to be too much extra work, so I simply write it down on a note pad that I always have on my desk.)  

Typically, I go through and review any outstanding warnings every two weeks along with the Revit audit feature. Once you resolve all of your warnings you should sit down with your BIM manager to ensure you are following company standards so you are optimizing performance and workflow inside your models.