I came accross this post on AU's website and thought I would share.  This is a really great tip written by Craig Thomas, Leo A Daly on June 15, 2010.  Click on the Source Link to see the original Post!

Associating Signs to Adjacent Rooms

Creating a signage schedule by room can be a challenge. Normally, the sign will report the room that it appears in, rather than the room that it is marking. This article shows one method of associating a sign to an adjacent room.

Our office decided that we did not need to actually model the sign. We chose instead to represent the sign schematically in plan. In this example, we will create a symbolic sign family that has an anchor that can be dropped into the adjacent room, if desired.

Getting Started

We start by creating a new Family. Certain objects that you want to model that do not have a clear place in the Revit Category hierarchy, and signs are one of them. I prefer using the Specialty Equipment.rft template, whereas some may prefer the Generic Model category. Others may consider it part of their Furniture. Select the template that best fits your needs. Save the family using your firm’s naming standard.

Whatever you decide, you will want to create a subcategory to separate signage from the remainder of the overall category. We do this by opening Object Styles from the Settings menu on the Manage tab. As you can see in the image below, I have already created a subcategory under Specialty Equipment called Signage. We will also need another sub-category to use for anchoring the sign to the room. By selecting the New button, the New Subcategory dialog is displayed. Once you give it a name and click OK, you can choose the lineweight, color, pattern and material that the subcategory should use.

Setting Up the Family Structure

As with most templates, two reference planes are already in the family. If you check the element Properties of each, you will notice that both have the Defines Origin checkbox checked. This determines where the object will be in relationship to your cursor when you place the object. For this family, the horizontal reference plane will represent the face of the wall in a project.

We need to locate two things: the symbolic line-work to show in plan and the anchor to associate with the room. It is always a good idea to create this structure using Reference Planes or Reference Lines. In this case, Reference Planes are most appropriate. Locate one plane 2-3 inches below the existing horizontal plane. This will control the symbolic line-work that represents the sign. Locate another plane 1 foot above the existing horizontal plane. This will control the sign anchor. Next, add a separate dimension from the original horizontal plane to each of the planes added.

Adding a Parameter to Locate the Anchor

Select the dimension that locates the sign anchor reference plane. On the Options Bar you will find the Label option as shown in the image at left. Pick the down arrow and select parameter…>. This opens the Parameter Properties dialog box. By adding a parameter this way, you do not have to worry about choosing the correct type of parameter to use. The type is already selected and grayed out because you picked an object that requires that parameter type. Your cursor should be at the Name textbox. Enter a name for this parameter. In this example, I chose Sign Anchor. Next, in the drop-down list under Group parameter under, select where you would like this parameter to show up in the Element Properties dialog box. I chose Graphics. Other options may make sense as well. If you are not sure, the default, Other will work. Finally, make sure that this parameter is an Instance parameter. This will allow the user to determine if the anchor for each individual sign should be dropped into another room or not.

If you think you will need to control the location of the symbolic line using a parameter, use the same technique described above to add a parameter to the dimension locating the symbolic line-work reference plane. If not, just leave it. You can always edit the Family if you decide it is too close or too far from the wall. Your family should look something like the image below.

Adding the line-work

Now add line-work to the structure we have created. Use the Symbolic Line command on the Detail panel of the Detail tab. Once selected, you should use the Type Selector to choose the Signage line style. This line style was created as a result of adding a subcategory. Draw the line as long as you want it to be, making sure to snap to the reference plane created earlier.

For the sign anchor, we will use a Model Line. We do this so that Revit will see the sign in the room where the line exists. Use the Model Line command in the Model panel of the Create tab. This time choose the Sign Anchor line style from the Type Selector. Again, make sure to snap to the reference plan controlling the sign anchor location. The length of this line is completely arbitrary, but needs to be long enough for Revit to see. My line is 1 foot long.

Use the Types command in the Family Properties panel to set the default Sign Anchor dimension. Set the default to 0’-0” if you expect that most of the signs will be placed in the room that they belong in. If you expect that most of the signs will placed in adjacent rooms (such as a corridor next to the door into the adjacent room), set the default to 1’-0”. You will be able to adjust each sign independently because we made the sign anchor an Instance parameter. Setting the default dimension saves you some time.

Using the Family in a Project

Now we can load it into our project. Use the Load into Project command if you have the destination project open, or open the project and use the Load Family command on the Load from Library panel on the Insert tab.

When you place the family, you will be locating it by selecting the face of a wall. Once placed, you can use the small arrows to drag the anchor into the adjacent room. The image above shows the anchor dragged into Office 102. The schedule above shows one sign in room 102 and two in 107.

Once you are happy with the behavior of the signs, you can turn off the anchor using Visibility/Graphics Overrides. On the Model Categories tab, scroll down to find Specialty Equipment. Expand it by selecting the plus (+) sign. Find Signage Anchor and remove the checkmark next to it.

With a bit more work you can add the Sign Message parameter and create the schedule, but that is a topic for another day. In this article we explored using simple line-work to associate a family with a room. Along the way we discovered the use of subcategories, length parameters, and the use of both model and symbolic lines. As you can see, careful creation of Revit Families can produce powerful results.