Did you know Revit did not always have a Scale command! For the first several years, there was literally no way to scale anything. We had Mirror, Copy, Rotate, but no Scale command. I think the logic stemmed from the idea that you would never scale building elements/components. For example, if a door or window were scaled, it should not get thicker or the hardware would not change size.
Here is an old AUGI fourm post, from 2003, showing an experienced AutoCAD user asking about the lack of a scale command in Revit: http://forums.augi.com/showthread.php?905-Scale-command
Even with the Scale command, there are some things that are still not able to be scaled. The above logic still applies... you cannot scale doors, windows, most families, etc. BTW, this command was originally called Resize; the keyboard shortcut still being RE.
From Revit help: "The Scale tool is available for lines, walls, images, DWG and DXF imports, reference planes, and position of dimensions. You can scale elements graphically or numerically."
I was recently using the beta version of Revit 2018 to develop a design for a competition, which I will talk more about in another post, and ran across a family I needed to scale down. To save time, I found this family online (don't remember where), but it was way too big (notice the 2'-2" dimension).
Luckily there is a trick to scale down any family... load the family into a Planting family and then load that family into another Planting family. Now the family has a built-in Type parameter called Height which scales the entire family up or down (this is normally used to change the height of a tree so they are not all the same).
Here is the family at the correct scale in the project...
And a 3D view to show more of the detail I did not want to model for a competition.
The light source in the original family still provided light when rendered!
I first learned about the great trick to scale an entire family from Marcello Sgambelluri. who is a top rated speaker at Autodesk University and BiLT (formerly RTC). We first met at RTC (Revit Technology Conference) in Stone Mountain Georgia in 2012 - we both had our families there. Check out his AU session on this topic here: AB3020: Size Does Matter: Learn How to Scale and Morp Families in Revit. He also has a great blog podcast, Simply Complex, which I will be on someday when our schedules align!