OP
Knobhead
It’s totally irrelevant to the OP. It was a basic two way switching set up, intermediates had nothing to do with the situation!Yes but if you have more than 2 switches controlling the same light or group of lights then only 2 of them can be 2 way, the rest will need to be intermediate, regardless of how many stories there are in your house.You could have a bungalow or single storey flat where the hall light is controlled by a switch by the front door, a switch by the lounge door and a switch by the bedroom door; one will be an intermediate.... Or if you were really lazy you could have your bedroom lights controlled by a switch by the door, and one on either side of the bed. Again, 3 switches, one of which is an intermediate.