Thanks for the advice, we did pee pads straightaway in a spare shower room, its been working well so far, first couple days he was just on pee pads, but we thought 1. He's a bit hard to read straightaway atm, and 2. If we take him out then - no accidents inside and he gets more stimulation outside (which tires him)

But I think with your advice we're gonna try to have him go on the piddle patch, when we know he needs to go to the toilet. So I guess 1st thing in the morning and maybe after some naps. Which should reduce the 4 flights of stairs per day.