As soon as I stepped back to admire my work, the cats were up on it. From opening the box to being done took about an hour. I suggest that you lay out all the pieces before starting. Also, I suggest that once you place the large top platform, put the large cubby on first and then the two posts. I placed the opening for the bottom cubby so it was facing a platform so the cats could get inout easily. Total coincidence that the plush matches my wall paint!