Back when we had a campervan it had a custom-made removable Barjo dog crate in rear. It had a divider panel across the middle which could be removed if you wanted to fit a Great Dane in it, or would allow two smaller dogs their owns spaces with the divider installed. The crate fitted between the Transit wheel arches and was 4ft wide by 2ft deep, giving each of our beardies a space roughly 2ft by 2ft. This was just enough for them to curl up and turn around in whilst keeping them relatively restrained in the case of any violent braking etc. The space they had (0.4square metres) has become a de facto standard measurement to assess dog crates by for beardies.
So I thought I'd look at the floorspace of caravans on the same basis, assessing how many beardie spaces they provided. Just to get things started, the campervan in question (SWB Transit) had the equivalent of 6 dog spaces (including the dog crate. Our current Bailey (not including the doorway) has 12. A Troll 540 has 9, a fixed bed 530 has 6 and a similar 550 has 7 or maybe 8. A 430 Triton has 7.
So there you are a handy ready reference to the amount of space a dog or dogs of medium size has in some Eribas. That is, of course, unless you let them on the benches or bed, when it's a whole different ball game.
' Ball? Ball? Did anyone say ball? I'm up for that'