1) Putting it over the window on the outside wall - this would be no problems from the inside, but the work required on the outside would be very tricky because there is a one story extension underneath which has a fairly steep sloping roof, the slope running perpundicular to the bathroom wall. I can't see any way of getting to the wall to make a hole/fit the outisde part of the fan. The roof is too low to stand on and there is no way of getting ladders up from the ground as the extension is in the way! Can anyone think of a way around this?
2) Put the fan on the ceiling and have it venting to outside through ducting to the (easily accessible) outside wall at the other side of the house. I don't think this is practical as the ducting would have to run about 2 metres through a cold loft and any steam would certainly condense before reaching the outside.
3) Put the fan on the ceiling and vent through the roof - wouldn't consider DIY-ing this so would have to get someone in to do it - any ideas how much this would potentially cost?
4) ...erm, I ran out at three - if anyone can come up with a workable alternative then please feel free to let me know!
Thanks in advance, Richard