Interesting topic . Whilst I think it would be odd for someone in U.K. to mention that their house had stairs ( which is the norm in UK , like having a roof ) .
It is something that a host should consider when selecting their sitter , especially if they are narrow or steep. We recently did a sit where the attic had been converted to a large family bathroom which had the only shower and bath in the house . The access was a narrow staircase ( not obvious from the photos. It was fine for us , but would have been difficult for some sitters .
Another issue with older properties in U.K. ( I mean 14th century old ) we have done a few sits in these characterful buildings .
During the video call pre confirming a sit the hosts asked how tall we were - which was relevant as they mentioned the low beams and how they themselves bumped their heads frequently in certain areas of the home .