The houses are mainly in the sound stages and tents behind the main park areas. You won't see anything related to the houses during the day. That's the one thing I discovered the first time I went to HHN in 2004...how big the Studios really is. There is so much more that guests don't see but during HHN, lots of the back stage parts are openI went to UO on a HHN and could see very little of what the party is made up of. Where do they do all the haunted houses? We were looking around to see if we could figure it out.