I actually started 15 - 20 yrs ago with 3 new windows down there & knocking walls out 12 yrs ago.
It's sometimes never ending -being a homeowner.
I kept the very back room the same as it's my laundry room & I keep tools there. The use of my washer & dryer is included in rent - as long as he doesn't take advantage & let others use it. He was told not to let anyone back there.
Legally, there has to be egress...a back exit, which is a door to laundry room which has a door exiting out the back. I figure a tenant might sneak the use of them when I'm gone so I'll let him use it.