Good size.  Not as solid as my last one.  The 3 platforms at the top aren't very soft, and the edges aren't very deep, so they don't 'hug' the cat. We're going to have to add beds or mats to them. The houses are not hard sided - they're little tents.  That said, it was replacing a 6 year old one with sisal falling off everywhere, and, for the price, it was good value.