Revit Rough Width/Height System Parameters

Making use of the Revit Rough Width and Rough Height System Parameters for Doors and Windows

Having heard lots of questions about how to control or remove the "Rough" system parameters, I thought I'd share a couple of tips I figured out for making them more useful.

Revit door and window templates provide several system parameters that cannot be deleted or renamed.  They are also Type parameters by default, which may not suit your purpose:

1. Width
2. Height
3. Rough Width
4. Rough Height

A lot of people don't use the "Rough" parameters, as the Width and Height are sufficient.  Here is a way to put the redundant system parameters to use:

Let's suppose that the overall sizes of your window families are controlled by type parameters Width and Height.  Most people have a naming convention for the windows that include the sizes in the name - eg.  WN_1800x1200
There is always a chance that a user will duplicate a type and name it wrongly, or make a mistake so that the name does not match the actual size.  This can be annoying or even dangerous if someone makes an assumption about the size without checking (which involves going into the Type properties dialog box).

There is a simple way to make it much easier to check on the fly.  Add a couple of basic formulas to the Rough parameters

• Rough Width = Width
• Rough Height = Height

Type to Instance

Now we want those Rough parameters to be instance parameters, but apparently you can't change them as the "Modify" icon is grayed out when you select one

• Go back to the plan view and select the Width dimension;  
• change it to "Rough Width";
• Check the "Instance Parameter" box in the options bar;
• Change the dimension back to the Width parameter;

Repeat this operation for the Height dimension in the front elevation view;

When you load the family into a project and place a window, the window instance properties will display the size (Rough Width and Height), but they will be grayed out so you can't change the size without going into the type properties.

Its a simple but effective way to make use of those annoying redundant system parameters.   It also shows an easy way to change system parameters from type to instance in the family.