6/50
Shadow Lawn (Wilson Hall), New Jersey
This 130-room building in New Jersey is located on 90,000 square feet and was once Woodrow Wilson's vacation home. It became part of Monmouth University in 1956 and was featured in the movie Annie.
If you're thinking vacation homes are a little less presidential, check out some of the great cabins you should see.
7/50
Pensmore, Missouri
This massive 72,000 square foot home was built to be tornado-proof, bomb-proof, and earthquake-proof. It is built of insulated concrete forms and is called Chateau Pensmore. At the facility, located near Ozark, Missouri, astrophysicist Stephen Huff built reinforced steel called Helix into concrete that can withstand EF-5 tornadoes, allowing it to bend without breaking during a tornado. It was constructed as follows. For a more practical solution to preparing for a tornado, check out your rain shelter location.
8/50
The One, California
The iconic Hearst Castle once topped the list of California's largest homes, but that position has been usurped. The One, a newly completed 100,000-square-foot mega-mansion built by real estate mogul Nile Niami, is expected to sell for at least $340 million. That would make it the largest and most expensive home in the United States.
Featuring a futuristic design, The One features 20 bedrooms, 30 bathrooms and five pools, as well as a movie theater, 50-space parking and a private nightclub.
You can increase the square footage of your home, perhaps on a small scale.