The house on the series, not any of the movies.

I know I've talked about this several times either here or on the Hazel thread. But the answer to your question is Gidget's house is the Hazel house the Don Defore era Hazel house. They re-arranged the stairway a bit but it's the same house. The kitchen is exactly the same as Hazel, even same appliances.

I think also you will see the bedroom of Donna & Alex from The Donna Reed Show on Gidget, at the least it's a re-use of the closet doors. So it's worth looking at the various Screen Gems shows for examples of newer uses.