Piece of cake. Lots of ducting available to go on the wall, under the floor, in the floor void above etc.
You'll need a centifugal pump to get enough pressure but they're common.
Google it - eg
http://www.bes.co.uk/products/180.asp
You need the right m³/hr so make sure there's somewhere for the air to get IN to replace what's going out or nothing will move. Vent in the door is the usual.
My builder has now started work on our downstairs toilet. He has bought 4" round pipes that he is going to duct through our floorboards and exit beside the front door.
What type of extractor fan would be suitable, preferably from
screwfix
website.
You mentioned earlier about centifugal pump, to get enough pressure, so we'll look at screw fix, as I want it now.
Vent in the door, the builder has not mentioned it. Does it mean that he has cut the door, which is newly fitted by him, to allow air inside the toilet? I'll ask him cut from below and leave a half an inch, to for air to enter, instead of fitting those ugly fixed vents in the new door.
I'm worried about draft entering from 4" exit hole that he cut out.
I'm stuck as I hired this foreign builder who speak little english and probably has now knowledge about extraction in confined space!
He has fitted the extractor fan with the light switch, so if anyone goes for a pee or brush his/her teeth the bloody fan comes on, is there a simpler way of having separate switch for fan and light, however he has done the wall tiling, so wonder if it's too late!
I like to separate switch for our downstairs toilet for fan and light, as he hasn't done wiring yet and not tiled it.