
I would say this was not acceptable for the reasons you have stated.
with a dog as small as a JRT surely they have room in the house for a whelping box and a puppy pen. Once pups are say five weeks old then a pen attached to this bui9lding with the door and winsows open will maybe be useful for shelter while they are outside to play.
To make this into a safe kennel the roofing and ventilation would need to be addressed.