REVIT INTERFERENCE CHECK

Revit has inbuilt interference checking (called Clash Detective in Navisworks).

It is quite simple to use, but has limitations (see below).

Revit command:

Collaborate > Interference Check > Run Interference Check .

Left side checks against right side.

Select categories to check.

It is possible to select a linked Revit file and categories within it.

Hit OK and Revit creates a report.

Selecting an item in report highlights it, hit Show button to zoom to object.

Report can be exported as HTML file.

Workflow

• 1. Create 3D view showing only objects being checked. Make sure all of those objects are visible; be careful with the scope box.

  2. Change Visual Style to Shaded (not Shaded with Edges). This will speed up zooming in the view.

  3. Create Interference Check report (see Revit Command above).

  4. Leave the report open while you zoom around the view looking for highlighted items.

  5. - Use Show button if you can't see the highlighted object.

  6. - You can also go to other views (e.g. Plan) and the current object will still be highlighted.

  7. - Pick a highlighted object in a view to get its properties to show in the Properties window. Identify its level from these properties.

  8. If possible make changes to resolve clash, then hit Refresh button in the report window.

  9. You could also save a screen grab of a clash. If you do make sure you identify the location in the file name.

To Check only part of a project:

If the project is broken into linked files, do Interference Checking in a linked file.

You can also create a separate Revit file to check:

• 1. Select the objects you want to include.

  2. Make them a group.

  3. Select the group in the Project Browser.

  4. Right click and select Save Group…

  5. Open the file, link files you want to check against.

Limitations

• • All objects of selected categories are checked. For example you can not just check one level.

  • You can only check the current file against itself or one other linked file at a time. e.g. you can not check architecture (current file), structural link and mechanical link in one run.

  • The report doesn't identify which level an object is hosted on, it only reports Mark parameter and ID number.

  • The report numbers each clash but these numbers have no relevance inside Revit - they can't be used to identify the clash in Revit.

  • You can not use Select by ID on objects inside linked files.

  • You can not edit objects in linked files to overcome clashes. - although you can open linked files and run a matched Interference Check.

  • When you run a new Interference Check the previous Report is overwritten (though you can Export a report).

  • Some objects (like Air Terminals, Pipes) will always create a clash as penetrations are not usually modeled for them.

  • You can't ignore clashes that you know are legit.

  • Once you run thru all the collisions, since you can't ignore clashes, if you run the interference check again in a week, you'll have all the same clashes (that you wanted to ignore), that you'll have to go thru again...

VISUAL CHECK

If you only want to check particular areas a human visual check can be the best method to use.

Workflow

• 1. Create 3D views showing only objects being checked (both in current project and linked file).

  2. Use scope box to limit view to identifiable area (e.g. a level).

  3. Give objects being checked contrasting colours.

  4. Note you can not change colour (i.e. Material) of objects in linked files. It can only be done by opening the linked file, making the changes, and saving it.

  5. Zoom around to show clashes.

  6. Save screen grabs of view of clashes.