So I am buying piggies this summer, 2 girls. I am setting things up this month before we get them. I have bought a small playhouse, 4x4, I am planning to insulate with reflective bubble insulation and then go over with plywood. First question is how far up the wall do I need to cover with plywood, I was thinking half way up the walls would be enough? And also there are two holes for ventilation, at the top, but do I need more? I was planning to leave the glass in the windows but they can open. But especially in the winter I am not sure id keep them open all day. should I be drilling more holes for ventilation, maybe half way up the sides so not to be too drafty? I was going to put the house on bricks to raise it, but I have got an empty pallet, would that be sufficient? I