Complex sentence: The house has been owned by a number of families since it was built, and was restored in 1937 The Historic American Buildings Survey notes that it was restored in 1937, which was when the survey made photographs of the building.
Split into simpler sentences: The house has been owned by a number of families since it was built. It was restored in 1937 The Historic American Buildings Survey notes that it was restored in 1937, when the survey photographed the building.