Add reference planes for measurement to family

[cbt990]

How do I add an invisible reference to this window family so that I can dimension to the centerline? the line running through the center currently is just a model line that I added because I knew it would always be visible. I will delete it once I have the window placed correctly, but then my dimensions wouldn't be valid anymore.

So I am trying to have this center line pop up as an option for dimensioning.

Thanks for the help

[barthbradley · Accepted solution]

In the Window Family add a Center Ref. Plane and make it a "Strong Reference" under the RP's "Is Reference" Property.  

...I'm surprised it doesn't exist already.

...BTW: you can make any RP pickable in the Project environment (for dimensioning, aligning, etc.) just by using an Is Reference other than "Not a Reference". 

[syman2000]

Why not use invisible line inside the window family? That way it won't show up but it is still there.