Was fairly easy to build - just take not of the instructions and separate the "bolts" into groups of A B C etc.It is much taller than I expected - Mel loves sitting at the very top which is almost eye-level with daddy. Daddy is about 58"My only issue is it might be harder for an older cat - Mel is only 4 - to get up and down easily - maybe add a custom ramp.But Mel loves it and your cats will too. Pic is of him sitting at the top on his snuggle rug. I actually bought 2 so has one in the living room and the bedroom - though he still likes sleeping on my bed but during the day loves looking out the window from it.