This was very easy to set up. I did it by myself. There is no need to buy one the next size larger than the trampoline. I bought one for our 15’ trampoline. Material is very thin. If left on for extended length of time I can see this getting ripped from being in the wind. Not enough head clearance for older kids. 
Update:  it rained last night while this clubhouse was still on the trampoline. Even though there is a round screen vent in the roof water collected on the roof and ripped the clubhouse by two of the pools. The weight of the water was too heavy. I would not recommend buying this item. It would be too much work putting it on and taking it off for one day of play.  $120 down the drain.