Pouring concrete slab

I know very little about concrete, but ISTM that's effectively pouring a large paving slab. There's no rebar and it's not very thick, so I suspect it's not going to handle heavy loads (like a wall on it). I'm sure it's fine for a chicken coop (<50kg) but I wouldn't use it as the foundations for a building.

Also it may not stay level if there's any ground heave, since it's not bedded on anything but dirt and there's no gravel or anything underneath to absorb ground movement.

Theo

It's only temporary though. In time the area will be a part of a large patio they say. The rich concrete mix and increased thickness around the edge will help surely. It should be ok for a door step for a few years.

I've seen this couple before and they admit that in a high traffic area outside their caravan the concrete cracked up. OK maybe for a static slap such as a little used shed base.