About 4 years ago we build our first Haunted House for our PTO's Trunk-or-Treat event. Every year since then I've improved the process a little to make it easier to setup and dissemble. - the use of shower curtains to hang the backdrops reduced the setup time significantly. The time consuming part is building the components for the structure - which is modular and can be broken down for storage. We can setup an 8 -room Haunted house in about 30 minutes - not including the time to add props.
We've build this outdoors a few times, but the wind is your enemy. The structure is light-weight and the backdrops act like huge sails, so a strong breeze can blow it over. If you build it outside you may want to weigh down the frame using cinder blocks.