the plan

I am going to be doing some work on my bathroom. I'm not quite sure what the correct name for this is, remodeling, rehabbing, gut and build? I am going to be removing all the walls down to the studs, fix any electrical and plumbing issues found, add an outlet and exhaust fan, replace the window, put up concrete board in the shower and green board elsewhere and putting up new tile.

The house was built in the 1930's, 1934 I believe. So the original construction reflects the time. The walls are plaster and lath, there is a wood frame window in the bathroom over the tub, and the original electrical was knob and tube. Over the years there have been some updates. As far as I know there is no more knob and tube in the house, there is still some in the detached garage however. I don't believe the tile in the bathroom is original. Over the years water has permeated the walls and some of the plaster in the shower is starting to fail. We noticed that some of the tiles were swelling out, but until they were removed I didn't realize how bad the damage was. The tiles were the only thing holding the plaster in place. As I removed tiles, plaster power fell out of the wall. The good news was that it was a limited area that was failing. Other area appear to be fine.