This product was received in multiple HEAVY packages (all delivered at the same time).  I assembled in a leisurely 5 hours (my wife helped lift the twin bed on top of the full bed, but other than that, I assembled solo).  The instructions were easy to follow and I had no issues with the construction.    The finished product seems to be very sturdy as I climbed on the stairs and both beds (180 lbs).  I'd recommend this product.  I did add felt furniture strips to the bottom of the bed posts and stairs to prevent scratches on the wood floors, but all you need is Phillips screw driver.