1. Carolands Chateau
First on our list is a 46,050-square-foot, 4.5-floor mansion owned by Charles and Ann Johnson. The Johnsons who uses the mansion as gathering place for their very large family spent a whopping $20 million on the restoration of this early 1900s, 98-room California Historical Landmark on 5.83 acres. The building, which is also listed on the National Register of Historic Places has had a lot of twists and turns over the past decades – which includes a murder case and natural disaster.
2. Nottoway Plantation
The Nottoway Plantation comes next as the biggest houses in the world. Built-in 1859 by John Hampden Randolph, this historic building remains the largest plantation in all of America with 53,000 square feet (4,900 m2) of floor space. The building is located close to White Castle, Louisiana, United States. It is currently owned by Paul Ramsay and has a total of 64-rooms with 165 doors and 200 windows. The building, which has a Greek Revival and Italianate-style, is currently used as an inn popular tourist attraction.