add a shower to a an existing 1/2 bath
I have expanded my 1/2 bath in my downstairs tri-level. I actually have enough room for a small shower. I may consider it, however, I would like to know if you can install an exhaust vent system that I can vent out horizontally through an outside wall (like a dryer vent almost). I am 3 floors down and I'd have to go through existing walls/floors to the roof for a vent. It would be a huge job and involve ripping up several walls and rooms to get to the roof.
Is horizontal venting possible / legal to do? the wall I have to get to is less than 9 feet way and I could travel the vent duct between the floor joists above to that wall and outside.
any help or suggestions welcome,