2 story house plans (sometimes written "two story house plans") are probably the most popular story configuration for a primary residence. A traditional 2 story house plan presents the main living spaces (living room, kitchen, etc) on the main level, while all bedrooms reside upstairs. A more modern two story house plan features its master bedroom on the main level, while the kid/guest rooms remain upstairs. 2 story house plans can cut costs by minimizing the size of the foundation and are often used when building on sloped sites. Two story house plans also typically offer less roof area than their single story counterparts which can make them more energy efficient, especially in colder climates.