Multiplying width by length yields square footage. As an example, if a room is 17 feet wide by 17 feet long, 17 × 17 = 289 square feet. There are in total 2.1 million sq ft of floor space in the White House. The first lady's family shares this space with the staff who live and work there. The size of your room will depend on how much space you need to live comfortably. If you have a family, then you will need more than one room. The square footage of a room is also called its "footprint." Footprint is the amount of area occupied by a single object, such as a chair or bed. So, the footprint of a room is the area it takes up. The more space you need, the more money you can spend on luxury items such as fine furniture or large windows. As well as being important for keeping rooms together, the shape of a building's exterior also has implications for what can be done inside it. For example, a roof that covers only part of the room means that some expensive upgrades won't be possible. Such as installing solar panels or an energy-efficient heating system. In conclusion, a square foot is a unit used to measure floor space.