I bought one at petsmart that had to be assembled and hadthe sharp edges and splinters, I sanded it down some. The boys use that one.
The timber hide-a-ways are better, smoothe too. I gave the medium sized one to the gerbils, the large one is in my basement out of use at themoment. I don't use any houses for most of my pigs. The boys have a house on their upper decks, right now fudge and Ollie have the wooden house and a cuddl-e cup, Sparky and Rover have a stool and a log cabin that came with chloe and Lila from their former adopter.
I've got 3 large fiddle sticks, about 5 children's step stools, and 6 pigloos in addition to the timber hide-a-way that are stored in the basment for the time being.