Largest House by State 2025

North Carolina

The largest home in the United States is the Biltmore Estate, which is located in Asheville, North Carolina. It is 175,000 square feet, making it around 70,000 square feet larger than the next biggest home in America. The Vanderbilt family built this in 1889 and it was finished in 1895. The Vanderbilt family had made their fortune during the railroad boom, where they acted both as traders and worked on the railroad itself. The family opened the Estate to the public in 1930, quickly becoming one of the top tourist attractions in the area. The large mansion has 35 bedrooms, 65 fireplaces, and around 43 bathrooms.

New York

You may recognize the next house from movies such as “Citizen Kane”. The Oheka Castle located in the state of New York is a whopping 109,000 square feet. It was built between 1914 and 1919 for the cost of 11 million dollars, which translates to roughly 158 million dollars in the equivalent purchasing power of today’s currency. This large house was built by Otto Kahn, who made his fortune financing the building and reorganization of the railroad network throughout the country.

Oheka Castle has since been turned into a luxury hotel and includes a large golf course. In the past, celebrity guests would attend as there was a private airstrip attached to the hotel.

Pennsylvania

The Gray Towers Castle, located in Pennsylvania, is modeled after Alnwick Castle - a medieval structure in England. The castle was initially built for William Welsh Harrison and designed by famous architect Horace Trumbauer. Harrison was a sugar magnate, expanding his trade all over the country - and sourcing it from various suppliers in the Caribbean. Grey Towers c\Castle is the 18th largest house in the U.S. and was officially added to Arcadia University as part of their campus in 1929. What used to be regal bedrooms are now used as student housing, where most are vying for the opportunity to take part in its eclectic history.

The architecture of the house is extremely peculiar and impressive at the same time. The entire structure is said to have been built without a single nail. As is with all large houses that were built many decades ago, the house is rumored to be haunted with various spirits lingering in the halls.

Delaware

Winterthur Mansion, located in the small state of Delaware, is the third largest house in the United States. It was built under the direction of the famous du Pont family and was eventually completed in 1932. The Du Pont family were well known to be art collectors, which has made the house into the beautiful museum and library that it is today. The mansion was donated to the state in 1951 in the hope of enriching the lives of the public, who can enter the grounds on many days of the year. There are 175 rooms in the house and it is situated on nearly 1000 acres of grounds and natural gardens.