A bunker house is a high-security shelter designed to protect its occupants from various threats such as nuclear war, global pandemics, earthquakes, civil unrest, chemical agents, and weather events like tornadoes and hurricanes. Bunkers are almost always underground, in contrast to trench bunkers which are small concrete structures, partly dug into the ground. Bunker houses can be relatively simple steel tubes or reinforced shipping containers buried in a suburban backyard, or they can be elaborate whole-house structures, or even communities, with multiple rooms, state-of-the-art entertainment centers, wine vaults, hidden escape tunnels, and even swimming pools and hydroponic garden systems to grow fresh vegetables. Sometimes decommissioned military sites and equipment, such as missile silos and vast storage facilities, can be repurposed as civilian bunkers.

Bunker houses can have various features, such as a full kitchen, two full baths, closets, and a pantry. They can also have ventilation/circulation systems, central heat & cool, private wells, and septic systems. Residential bunker houses can be purpose-built with a bunker, and the normal location is a reinforced below-ground bathroom with fiber-reinforced plastic shells.

Bunker houses are often associated with survivalists and “preppers” who are preparing for the end of civilization as we know it. There are now companies that specialize in the design and construction of underground bunkers, offering everything from weapons rooms to nuclear, biological, and chemical (NBC) air-filtration systems and gastight and waterproof doors. There are also real estate brokers who specialize in selling homes with private bunkers.