A nine year old and a 12 year old reviewed the directions with me and we put it together in about an hour. The extra pieces were appreciated. The only problem was the slat spacers which were hard to press into place and were prone to pinching the skin on your palm into a blood blister when they snapped into place. The space between the top of the bottom mattress and the bottom of the top bunk  is too small and lead to bumped heads.