outdoor hose bibb
 

I am having a new block fence/gate installed and a hose bibb is in the way, they want to put an "elbow" on it and move it about 11 inches, what is the right thing to do ?

Can't say a whole lot without seeing it, or knowing more specifics. One thing I can think of, however, is if it's a freeze proof type. Will they be removing that and exposing the plumbing to the cold winter air? If so, it could cause the pipe to freeze up and possible burst.

Welcome JoTa:
If you have a basement or crawl space that the hose bibb comes from you can go inside and do the re-piping to a new location and screw the hose bibb back on. If yours is not a frost proof (which runs at least a foot into the house) you will need to get one. Then drilling a new hole will solve the problem. Be sure to fill the old hole with something mouse-proof.
Glenn