Saturday, 3 August 2013

Parameters Part 2 - Filters

My first post on parameters introduced the concept of parameters, the differences between instance and type parameters and why you would used shared instead of project parameters.

This post will look at Filters and how parameters can be used to effectively filter objects based on the value of the parameters which is a powerful technique. Filters are akin to to combination of Filter and Conditional Formatting in Excel.

Some of my examples included parameters for fire rating which for buildings is a very important attribute of many building elements including walls, doors, windows, etc. Traditionally the information relating to fire performance of these elements is conveyed through fire drawings and specifications. The fire drawings typically use the floor plans as an underlay and the fire information is overlaid on it. The 60 minute compartments are indicated using red lines, 30 minute using blue lines, etc. This works well as it is visual and can be quickly interpreted by everyone without too much difficulty. There are two drawbacks though:

  1. The drawings are created for a specific purpose, usually for building control approval and the information tends to be static.
  2. The colour fire drawings must be cross referenced every time anything related to fire control issues arise.

What if we could assign the performance to the wall or door through a parameter and let Revit colour that wall or door red if 60 a minute fire rating is required. As an output we achieve the same effect perhaps with a little more accuracy in linework. We do now have the advantage that when anyone else interrogates the properties of the wall in any view, they can quickly identify the fire performance required of that wall without having to look at the views for the fire drawings or the printed PDFs/DWFs or sheets. As everything in Revit is in 3D, this transcends to sections, elevations, 3D views and schedules. If the person quantifying materials uses DWF, the data for all the walls and doors can also be interrogated through the properties panel in Autodesk Design Review. The end result is better coordination through the information being immediately to hand and less ambiguity as the data is current. We are now leveraging the i in BiM.


Filters change the way a view looks. Make a copy of a floor plan view by right clicking on the floor plan view and selecting either Duplicate or Duplicate with Detailing. If you Duplicate with Detailing, all annotations including room tags, text annotation will copy also. The floor plan will have colour lines indicating the fire performance for walls which the fire engineer has marked up in the fire strategy report. Give the view an appropriate name.

In the properties windows, select Visibility Graphics or use VG at the command prompt if you are more familiar with keyboard shortcuts. The last tab is named filters.

The list of filters is initially empty. Filters come in 2 parts which is not as obvious as it should be in Revit.

  1. The Filter itself i.e. give me all walls whose fire rating is 60 minutes
  2. How the filter is applied to this view i.e. show the hatch of the wall as solid blue.

To create a new Filter, click the Edit/New button at the bottom. You will be prompted to give the filter a name. There is no rules for filter names, just keep them readable and consistent.
The list of filters already created in this project will appear on the left hand side. Using the buttons below this list, you can create a new filter, copy one of the filters on the list, rename or delete a filter.

Categories are the Family Categories which you can filter on. Remember in the first post, I applied the Fire Performance shared parameter to both Walls and Doors. If I select Walls and Doors as Categories, I can filter by Fire Performance but if I add Ceilings, Fire Performance will not be available. Unless of course, I go back and edit the Parameter for Fire Performance to include Ceilings in the list of Categories.

I will select Walls for now. Select Fire Performance as the filter, select equals as the condition and then type a value you want to use for 30 minute fire rating. I am using FR30 which is my code for Fire rating 30 Minute. Click OK or Apply to save your filter.

We have changed nothing graphically on our view, we have just created the means to select all walls who value for Fire Performance equals FR30. Back in the Filter tab of Visibility Graphics dialog, click the Add button.

Select the filter you created from the list and click OK.

The filter will appear in the list of filters and you now have the option to override some of the visibility settings. I want all 30 minute fire rated walls to have a blue solid hatch so I will override the pattern for Cut.

Click OK and now all your walls which have a property of FR30 for Fire Performance will have a solid blue hatch.

Solid Hatch works well for walls but not for doors as doors don't have a hatch pattern. I have created separate filters for walls and doors and then individual filters for each fire rating.

And the final output looks like this:

The first time you create the filters, it can seem like a little effort. If you Save the View as a View Template, you can then apply it to all fire strategy views. The views including any filters created can be copied to other projects using Transfer Project Standards under the Manage tab so all your effort can be replicated quickly.

Important Notes

I haven't figured out an effective means to apply colour to Curtain walls. I have added model lines for now as a workaround. I will update this post when I figure it out. Suggestions are welcome.

Fire Rating is an inbuilt parameter in Revit. I used Fire Performance for my instance parameter for walls and doors to avoid confusion when selecting parameters.


I have used filters to create different graphical views of drawings for the purpose of improving the processes of creating and maintaining fire performance data for elements in buildings. This is only the tip of the ice berg as to what can be done. You can include 2 rules in a filter and colour all rooms where the occupancy exceeds 10 people in the Biotechnology department. Instead of adding colour, you could use the visibility property of the filter to hide all elements that are not structural. The list is endless.

A sample project is available on Google Docs.

No comments:

Post a Comment