Bought this about 2 weeks ago. Spent about 2/5 hours over 2 days to build all the wood parts. One board was split. They replaced it within a week. Then yesterday myself, wife, son, and neighbor put up the 4 legs, I attached the side pieces while they held everything steady. My son helped me put the frame in place for the top roof. I did the complete rest by myself. 6 hours yesterday and 3 hours today. So, including building the wood parts, about 12 hours total, most by myself. There are no written instructions, but the drawings are great. If you carefully follow the drawings, you will do just fine. The drawings were amazing. Showed all the holes, so you can't go wrong. They even highlight areas that would otherwise be tough to see.
We absolutely LOVE our 12x16 gazebo! It took my boyfriend 2 days by himself (he refused to ask for help) but if you have a couple people, or 5 people like the instructions suggest, it could easily be done in 3 or 4 hours! We love in the Pacific Northwest and it's great to sit under during a good storm!